RISA-3D Rapid Interactive Structural Analysis – 3-Dimensional Version 5.0 User’s Guide RISA TECHNOLOGIES 26632 Towne Centre Drive, Suite 210 Foothill Ranch, California 92610 (949) 951-5815 (949) 951-5848 (FAX) www.risatech.
Copyright 2003 by RISA Technologies All rights reserved. No portion of the contents of this publication may be reproduced or transmitted in any means without the express written permission of RISA Technologies. We have done our best to insure that the material found in this publication is both useful and accurate.
Table of Contents Before You Begin 1 Model View 49 How to Use the Manuals 1 Plot Options 51 License Agreement 2 Multiple Views 52 Installation 3 Selection Tools 53 Technical Support 3 Making Changes to Selections 56 Maintenance 3 Modify Members 57 4 Model Rendering 58 Defining the Model 4 Copying Model Elements 58 Solving the Model 4 Connecting Along Members 60 Reviewing the Results 5 Selecting Planes 65 Important Assumption! 5 Drawing Plates 66 Conventions Used in
RISA-3D User’s Guide II Tutorial 5 – Dynamic Analysis 108 Printing Graphic Results 101 Tiling Results Windows 101 Dynamic Solution 108 Batch Solution 102 Frequencies and Mode Shapes 109 Envelope Solution 103 Response Spectra Analysis 111 Code Check Results 104 Modal Participation 112 Optimizing Steel Shapes 104 Scaling Factors 112 Excluding Results 104 Load Combinations with RSA Results 113 Printing Desired Results 105 Conclusion 115 Version 5.
Before You Begin Before You Begin How to Use the Manuals This Guide is designed to be read in two ways. If you are already familiar with structural modeling in general you can skip the supporting text and read only the underlined action items to move through the tutorials very quickly. To do this read the rest of this Before You Begin section and then skip to page 6 and look for the underlined action items.
RISA-3D User’s Guide License Agreement END-USER LICENSE AGREEMENT FOR RISA TECHNOLOGIES® SOFTWARE: The RISA-33D software product (SOFTWARE PRODUCT) includes computer software, the associated media, any printed materials, and any "online" or electronic documentation. By installing, copying or otherwise using the SOFTWARE PRODUCT, you agree to be bound by the terms of this agreement. If you do not agree with the terms of this agreement RISA Technologies is unwilling to license the SOFTWARE PRODUCT to you.
Before You Begin Installation To install RISA-3D please follow these instructions: 1) Put the RISA-3D CD in your computer CD drive. 2) If the CD starts automatically go to step 4. If the CD does not start after 10 seconds click the Windows Start button and select Run. 3) In the Run dialog box type “d:\risacd” (where “d” is the label of your CD drive) and then click the OK button. 4) Follow the on-screen instructions.
RISA-3D User’s Guide Overview Using computer software to perform structural design is essentially a three-step process. First, you define your model. Next you solve that model to obtain solution results. Last, you review those solution results to see how your model performed and determine if changes are needed. Usually you will need to repeat the cycle several times before you arrive at a final design. The purpose of RISA3D is to speed up this process.
Overview Reviewing the Results You can review your results graphically or with the spreadsheets. Spreadsheet solution results (displacements, forces, stresses, etc.) are listed on the Results menu. You can sort and filter these results to get exactly what you want. In the button and choose the results graphic views you can click on the Plot Options that you want to display; force diagrams, plate contours, deflected shapes, etc.
RISA-3D User’s Guide First Look at RISA-3D Starting RISA-3D So lets take a quick first look at RISA-3D and then we’ll begin the tutorial. Start the program as shown below by clicking on the Start button and then choose Programs and then RISA and finally RISA-3D. The remainder of this chapter will give an overall guide of what you have in front of you. (The next action item is on page 15.
First Look at RISA-3D The RISA-3D logo image in the center of the screen will disappear after a few seconds. Lets take a moment to explain what you have in front of you. Title Bar The bar along the top of the screen is called the title bar. It contains the name of the file that is currently open in RISA-3D. The three buttons on the far right side of the title bar are used to control the main window. The button will shrink RISA-3D to a button on the taskbar.
RISA-3D User’s Guide Results – All analysis result spreadsheets may be accessed from this menu. Tools – RISA-3D provides features to help you organize identify and correct problems as you model the structure. Program preferences are also located here. Window – The Window menu can be used to manage all of the windows that you have open in RISA-3D whether they are spreadsheets or model views. Special tiling options are provided here that are geared to specific modeling tasks.
First Look at RISA-3D Drawing Toolbar The Drawing Toolbar is the third horizontal toolbar in the figure above. This toolbar may be turned on and off as needed to help you with graphic editing. Selection Toolbar The Selection Toolbar is the vertical toolbar along the left side of the screen. It provides selection tools to help you work with parts of the model. You will make selections when you do things like graphically edit only part of the model or print only part of the results.
RISA-3D User’s Guide Workspace The actual work that you do in RISA-3D will be in the main area on the screen, which we will call the workspace. Currently the workspace contains a white model view with the default drawing grid and the New Model options. (We will see how to change the default grid and many other defaults as we go along.) As we open new model views and spreadsheets they will also appear in the workspace. This brings us to the types or windows that we can work with.
First Look at RISA-3D Views You may open as many model view windows as you like. This is especially helpful when working in close on large models. You might have one overall view and a few views zoomed in and rotated to where you are currently working. You may have different information plotted in each view. One thing to remember is that the toolbars that RISA-3D displays depend upon what window is active. The active window is the one with the colored titlebar.
RISA-3D User’s Guide cell that moves around the spreadsheet as you hit the cursor keys (← , →), Page Up, Page Down, Home, End, etc. You may also select blocks of cells to work on. To select a block of cells, click and hold the mouse button on the first cell in the block and then drag the mouse to the opposite corner of the block and release the mouse. To select an entire row or column simply click the row or column button.
First Look at RISA-3D The middle message box is used to report the units of the current spreadsheet cell. As you move from cell to cell look to the middle status box for the appropriate units. Currently the box is empty because we are not working in a spreadsheet. The status box on the right is used to pass the mouse coordinates to you as you work in the model view. We will point this out again and use it to help us throughout the tutorial.
RISA-3D User’s Guide “What’s This?” “What’s This?” is a Help option that lets you point to an item in a dialog box and find a brief definition of the item. Click the button on the right side of the dialog title bar and the mouse cursor changes to allow you to then click on an item in the dialog. A brief description of the item will be displayed. For toolbars you may simply let your mouse hover over the button to display a description of the button.
Tutorial 1 - Modeling Tutorial 1 - Modeling So we have started RISA-3D and are ready to define our model. We should note here that your picture might not look exactly like the screen above. Your computer screen resolution and font sizes can change the appearance of the menu and toolbars. This is simply cosmetic and should not affect your ability to go through this tutorial. Starting a New File Starting a new file presents you with a clean slate with some initial options.
RISA-3D User’s Guide easily understand the templates and will be able to use the all of the power of RISA-3D. Click the button to start drawing members. Global Parameters Global Parameters are settings that apply to the model as a whole. This window is opened automatically because of this checked box that we mentioned above: Use your mouse to select the Description tab and click in the first field, labeled Model Title so that a flashing cursor appears there.
Tutorial 1 - Modeling Moving down, the P-Delta Tolerance is used to set the convergence tolerance for the P-Delta analysis. Leave this set to 0.5%. The Vertical Axis option is used to indicate which of the three global axes (X, Y or Z) is to be considered the vertical axis. For this model, leave this set to “Y”; indicating the global Y-axis is the vertical axis. The Global Parameters dialog should now look like this: Use your mouse to select the Codes tab.
RISA-3D User’s Guide The choices for Wood Design Code and Concrete Design Code are NDS 91: ASD and ACI 99. We will use the the default specifications for the tutorial, which are already selected. Use your mouse to select the Concrete tab. The entries under the Concrete tab contain options related to the analysis and design of concrete members. The Shear Tie Options allow you to control the Number of Shear Regions that will be used when detailing a beam or column span.
Tutorial 1 - Modeling Checking the box for Bad Framing Warnings will produce a message in the error log whenever the program detects a member that is unsupported at either of its end joints. This can be common for models that contain cantilevers, rafters and such. Checking the box for Unused Force Warnings will produce messages on the member detail report that informs you when weak axis and torsional moments have been neglected. Before we close this window we’ll look at the buttons at the bottom.
RISA-3D User’s Guide Click on concrete. to indicate that the Material Type for our new members will be Notice that when you click them, the white circles will become filled to indicate that your choice has been accepted. These circles are known as radio buttons and are used when you must choose between two or more items that are mutually exclusive. To select a radio button, you may click on the circle itself or on the adjacent text.
Tutorial 1 - Modeling member are considered fixed to or released from the member's points of attachment (the end joints). Note • You should use member releases to model how members are attached to each other, for example how beams are connected to columns or other beams. Use boundary conditions to model how the structure is attached to its external points of support, for example how the columns are attached to the foundation. We will use fixed ends, so there is nothing to change here.
RISA-3D User’s Guide What we’ve done is define a drawing grid with an initial X-increment for our truss points of 3 ft followed by 4 equal increments of 3.75 ft each and a final increment of 3 ft. Note the use of the “@” symbol to define a series of equal increments. Our Y increments are set at the beam, the bottom chord and the top chord. Other things to notice here are that you may specify a radial grid and you may save the grid layout to use in other models.
Tutorial 1 - Modeling We will start by drawing a line from point A to point B as shown here: Move the mouse to the lower left corner of the grid (point A, location 0,0,0) and click once. You should now have a line drawn from that point to the mouse, this line follows the mouse as you move it. Also a joint has been created and labeled N1. If you don’t see this, it means you weren’t very close to the lower left grid point when you clicked, so try again. Now move straight up to point B, grid location (0,18.
RISA-3D User’s Guide The line that follows the mouse should now be anchored to this new grid point, joint N2, and your screen should now look like this: Now is a good time to point out the Undo button will undo any mistakes that you make. on the RISA Toolbar, which Let’s continue with our drawing. Since the second column is not attached to the member we have already drawn we need to “pick up” our pencil and move to the other side of the drawing grid to resume drawing.
Tutorial 1 - Modeling Move the mouse to the lower, right grid point (A) at coordinate (21,0,0) and click. Now move straight up to the grid point (B) at coordinate location (21,18.5,0) and click again. We now have a column on the left from joint N1 to joint N2, and another on the right from joint N3 to N4. Click the right mouse button to “pick-up” the pencil. Click the right mouse button again to stop drawing. This will pop the button back “up” and the cursor becomes the standard arrow .
RISA-3D User’s Guide Click on the Set Plot Options button . It is the first button on the Window Toolbar (the second horizontal toolbar). We’ll discuss the plot options in more detail later. For now, click on the second tab at the top, which is labeled Members. Now click on the button next to the words “Color Coded” and a black dot will indicate you have made this choice. Beneath this the first indented option is “Color Basis” and “Section Set” is already selected.
Tutorial 1 - Modeling The members should now be displayed in color. The legend is displayed in the upper right hand corner of the model view to tell you what the colors mean. We haven’t used any section sets yet, but that is about to change. The “na” color used for our columns indicates that they were not defined with section sets. Our columns are defined, now lets do the wood truss. Since these members are going to be different we will use a different Material Type. Click on the dialog again.
RISA-3D User’s Guide This sketch shows what you’ll draw next; lines from A to B, then B to C, then C to D and lastly from D to A: To begin drawing the truss chord, move the mouse to the top of the left side column at joint N2 (point A) at grid location (0,18.5,0) and click. Now move to the right to the top of the right side column at joint N4 (point B), grid location (21,18.5,0), and click again.
Tutorial 1 - Modeling Click the RIGHT mouse button somewhere in the middle of your screen and you will see this shortcut menu: This menu brings relevant options right to where you are currently working. Notice that all of the options have to do with the view that we are currently working with. If we were working in a spreadsheet the choices would be relevant to that spreadsheet. Note that the first option is called Recall Last Dialog and note also that next to it is “Ctrl-D”.
RISA-3D User’s Guide The dialog now looks like this: Now click Apply This sketch shows what will be drawn next; lines from A to B, then to C, etc. ending at point F: Move to point A, grid location (3, 22.5, 0), and click. Now move down to point B, grid location (3, 18.5, 0), and click. Move up and to the right to point C, grid location (6.75, 22.5, 0), and click. Next move down to point D, grid location (6.75, 18.5, 0), and click. Move up and to the right to point E, grid location (10.5, 22.
Tutorial 1 - Modeling This sketch shows what will be drawn next, lines from A to B, to C, etc. ending at point E: Move to point A, grid location (18, 22.5, 0), and click. Now move down to point B, grid location (18, 18.5, 0), and click. Next move up and left to point C, grid location (14.25, 22.5, 0), and click. Move down to point D, grid location (14.25, 18.5, 0), and click. Finally, move up and left to point E, grid location (10.5, 22.5, 0), and click.
RISA-3D User’s Guide Physical Members You may notice that we have defined our truss chords with one member, rather than multiple members between each panel point. RISA-3D’s Physical Member feature allows us to do this and much more. Physical Members automatically connect the members that frame into them. This means that you don’t have to use multiple members to model what is one Physical Member in the field.
Tutorial 1 - Modeling Wood Properties For our model we will modify the wood material for the truss members. The complete NDS species database is built into the program. Therefore, you can select any valid species / grade combination and RISA-3D will provide the design values. We are going to change the grade from “No.1” to “Select Structural”.
RISA-3D User’s Guide Type the following: Col-Rules, [TAB], [TAB], 14, [TAB], [TAB], 14, [ENTER] Steel-Bms, [TAB], [TAB], 12,[ENTER] Conc-Bms, [TAB], [TAB], 12 [TAB], [TAB], 10, [ENTER] Truss-Rules, [TAB], 10, [TAB], 3.5, [TAB], 6, [TAB], 1.5 This spreadsheet should look like the figure below: Notice there are several parameters available to control the suggested alternate shapes. You can define acceptable member depth and width ranges, and also code check ranges.
Tutorial 1 - Modeling Section Sets Spreadsheet On the Data Entry Toolbar click on and this window will open: Repetitive members are inherent in structural design and Section Sets provide an easy way to handle them. This will become even more apparent when we have RISA-3D pick new / optimized member sizes. Our truss has only nine web members but what if we had three trusses and we had to change the section, which we will do in part two of this tutorial.
RISA-3D User’s Guide Click the arrow next to the text that says “A36” to open the drop down menu of hot rolled materials. Select A992 for the beam material as shown in the figure below: Notice that the Section Set data consists of a number of entries. The Shape entry indicates the current size that will be used for the member. The Design List and Design Rules entries tell the program what list of shapes to use and what design restrictions to impose when it tries to re-design / optimize the member.
Tutorial 1 - Modeling The left side of the dialog contains a list of available shapes. The shape highlighted in blue indicates the currently selected shape which should be a W5X16. The rest of this dialog is pretty self-explanatory. The Shape Type is currently a Wide Flange but can be any of the others listed such as a WT or channel section. The Shape Database is currently the AISC database but you can also choose from Trade ARBED, or Canadian.
RISA-3D User’s Guide Select CS as the shape type (in the middle). Finally choose 14CS3.75X135 as the selection at the top of the list of available shapes. Click OK and you will return to the Sections Set spreadsheet. Again, the A, I and J properties will be updated as soon as you leave the cell. Click on the first cell in the Design List column to make this the active cell. Then click the arrow next to the text that says, “CU” to open the drop down menu of design list. Select CS as the design list.
Tutorial 1 - Modeling The design group for both members is currently set to Rectangular. While this is sufficient for the web members, we would like to use doubled members for the chords. Click on the Shape cell in the first row and and then click the arrow to open the dialog with the NDS Wood Database. Select to indicate that our top chords will consist of two back back to back rectangular sections. Click OK to return to the Section Sets spreadhseet. We’ve now changed the current shape to a Double 2x4.
RISA-3D User’s Guide Concrete Sections Click on the Concrete tab and take a moment to review the information given. We origninally chose to define our concrete member directly rather than use section sets. Therefore, we will not be defining any members using the section sets listed under the Concrete tab. Take a minute to review the information listed here. Just like with the steel and wood tabs, the information consists of a section Label, Shape, Design List, member Type, Material and Design Rules.
Tutorial 1 - Modeling Click on the Window menu. The top of the Window menu presents some arrangement and tiling options that we will get to later. At the bottom of the menu the open windows are listed. Notice that they are numbered in the order that we opened them starting with the Model View and ending with the Member Section Sets we just finished. The current window has a checkmark next to it. We can choose any of the open windows from this list at any time.
RISA-3D User’s Guide CRECT12X8 Change the member type by clicking the down arrow next to “Column”. Then select “Beam” from this drop down list. Finally, we want the beam to be fully fixed at both ends so select that option. When you are done, you screen should look like the following: Click Apply and we go back to the model view. Here is what you’ll be drawing; a line from A to B: Move to point A, grid location (0, 10, 0), and click. Now move right to point B, grid location (21, 10, 0), and click.
Tutorial 1 - Modeling Boundary Conditions We will now add boundary conditions at the base of the columns. Click on the Boundary Conditions button on the Drawing toolbar. You will be presented with the following dialog: Boundary conditions define how the model is constrained. All models must be attached to some external point or points of support. Boundary conditions are applied to particular joints.
RISA-3D User’s Guide Click the first down arrow in the X Translation field and you will see all the options available for the boundary conditions: Reaction - The “Reaction” code specifies full restraint for the indicated direction. No movement will be allowed in the indicated direction for this joint and a “reaction” will be calculated and reported. Fixed - The “Fixed” code also specifies full restraint for the joint in the indicated direction however no reaction is calculated.
Tutorial 1 - Modeling The dialog now looks like this: Click Apply. The mouse cursor now looks like this , which indicates that you are ready to apply the boundary condition to any joint that you click on. We want to apply the boundary condition to the base of both columns at joints N1 and N3. Click on joint N1 and then on joint N3. We are finished with the boundary conditions and your screen should look like this: Version 5.
RISA-3D User’s Guide To see how these boundary conditions were recorded click Data Entry toolbar to open the Boundary Conditions spreadsheet: on the We could edit the boundary conditions here, or add new ones. We could type in a boundary condition directly, usually by just typing the first letter such as “R” for reaction. We can also click on the arrow to view the available options. Saving Your Data This concludes Tutorial 1. The next tutorial teaches you how to make modifications to the model.
Tutorial 2 - Modifying Tutorial 2 – Modifying In this tutorial we will modify the 2D frame we defined in the last tutorial and use RISA-3D’s graphic editing features to expand it into a complete 3D frame. Make sure you start off correctly by opening the file mentioned next. After starting RISA-3D click the Open File button. In the File Open dialog select the file named “RISA-3D Tutorial 2 Starter” and click Open. Close the Global Parameters window by clicking OK and we will begin working in the model view.
RISA-3D User’s Guide Double-click the column on the left to obtain the following dialog: Click the tabs at the top to view the information on each page, some of which we have not covered yet. After scanning the pages click the End Releases tab. Change the J End Release to Bending Moment Released. Click OK to close the dialog. Now double-click the column on the right to change that one. Click the End Releases tab. Change the J End Release to Bending Moment Released. Click OK to close the dialog.
Tutorial 2 - Modifying Changing one or two items in the model is best handled in this manner. However, if you had to change a lot of members there is an easier way. This is where the graphical selection and editing tools in RISA-3D become very useful. Let’s learn more about the model view and how we can best put it to use. Close the dialog without making any changes by clicking Cancel. Model View Next we will learn how we can modify the model view.
RISA-3D User’s Guide the anchor point to the mouse. Move the mouse such that the part of the model you wish to zoom in on is enclosed in the box, then let the mouse button go. You can cancel the box zoom by dragging the mouse off of the model view window area. Go ahead and try a box zoom now. The other two buttons, and , zoom in or out on the model as a whole. The actual zooming is towards the center of the model view.
Tutorial 2 - Modifying Loads The next three items, , are provided to help you view the loads. We will come back to this once we have defined our loads. Toggling Items On and Off The remaining buttons are toggles and will control information in the new view. Click to toggle model rendering. We’ll cover rendering later on. Click to toggle the joint labels. Click to toggle the member labels. Click to toggle the boundaries. Click to toggle the global axes orientation on and off in the view.
RISA-3D User’s Guide Select the option by clicking the radio button next to it. If it is not already selected select Section Set from the Color Basis drop down menu. Click OK to close the Plot Options dialog. Note • You may make any plot options your default options by clicking the Save as Defaults button on the Misc tab. Multiple Views We demonstrated that you could have more than one view when we used the clone feature. Each view is independent and can be rotated, rendered, selected, etc.
Tutorial 2 - Modifying Close the second view by clicking in the title bar. Selection Tools Selections are important to modify and view only parts of the model. Stated simply, an item is “selected” if it is fully displayed graphically. An item is “unselected” if, instead of a display of the item, only a gray line shadow of the item is displayed. All of our model elements are “selected” at this time.
RISA-3D User’s Guide Click on this button . This “unselects” the entire model. See how the model is now displayed in gray? Now try each of the selection tools below. The Box Select and Box Unselect tools work as you might expect; you use them to draw a box around the part of the model you wish to select or unselect. Only items that are entirely in the box will be affected. To use these, first click the button then move the mouse to the model view.
Tutorial 2 - Modifying The Save/Recall button is used to save and recall selection states for the model. This is very helpful for large models that require more than just a few clicks to obtain a particular selection state. The Lock Unselected button, when pressed, causes all currently unselected items to stay unselected, no matter what other selection buttons are pressed, until this button is pressed again.
RISA-3D User’s Guide Making Changes to Selections Now click the Unselect All button, to unselect the entire model. Then click the button to change the model view to an XY. Then click to maximize the view plane. Click the Line Select Your cursor changes button. to indicate that you are now in the line selection mode. Click and hold your mouse button to create the start of your selection line near the left most truss web member. Move your cursor past the right most web member and release the mouse button.
Tutorial 2 - Modifying For these “modify” options a “Use?” checkbox is available for each item that may be modified. This indicates what parameters are applied. We saw this when we defined the boundary conditions. If the little box is not checked, the parameter won’t be used. Modify Members Now click on the Draw / Modify Members button on the Drawing Toolbar. Select the Modify Properties tab to view the modification options. Click on , and in the upper-left portion of this dialog.
RISA-3D User’s Guide Your model should now look this this: Model Rendering A powerful graphics option offered by RISA-3D is the ability to display a rendered image of the model. A rendered image shows each member plotted using a true scale representation of the shape assigned to the member. The subgroup beneath this button indicates how much of the member length is to be rendered.
Tutorial 2 - Modifying Click Apply. Our entire frame was “selected” so all of the frames were be copied. In addition to copying the joints and members, if we had any loads on the frames they would have been copied as well. Your structure should look like the following image: We will now add the connecting beams. First click to maximize the view plane. Then click the Draw / Modify Members button on the Drawing Toolbar. Be sure to click on the Draw Members tab.
RISA-3D User’s Guide Click on the joint in the middle of the front column that is labeled N48 to define the I-end of the first member. Then click on the middle joint on the middle column (N32) to define the J-end of the first member and the I-end of the second member. Then, finally, on the middle joint of the right-most column (N16) to define the J-end of the second member. Now we will define the member at the tops of the same columns. RIGHT click to pick up the pencil.
Tutorial 2 - Modifying Click Apply and then click on the three columns in the front; the same columns that we just connected with beams. New nodes will appear on the upper half of the columns between the two beams. Press Ctrl-D to recall the last dialog, then click on the Draw Members tab. Choose Cold Formed for your material type and select “Girt” for your Section Set. Change the end releases to Pinned at Both Ends.
RISA-3D User’s Guide Now RIGHT click to pick up the pencil. Then click on to bring up the Drawing Grid options and select the Snap To Options tab. The settings on this dialog allow you to set up a grid of graphical editing points along any orthogonal plane. They also allow you to automatically snap to the quarter or third points of existing members. Make sure the Quarter Points and Third Points boxes are checked.
Tutorial 2 - Modifying mouse cursor passes over them. Back in the model view our cursor is still which indicates that we are still in drawing mode. Move the pencil tip from the bottom of the front left column up the length of the column. When the tip of your cursor reaches the quarter point of the member a red dot will appear indicating the presence of a graphical editing point. When this point appears, the status bar will display the coordinate location of the drawing point.
RISA-3D User’s Guide We are finished drawing, so right click to pick up the pencil and RIGHT click again to stop drawing altogether. Now we will select and then copy these new members to the other side. button and then click on the members that we just Click the Unselect All drew so that they are the only members that are selected like this: Now click on the Copy X inc field and type: button again. Click the Clear button and click in the -21 Click Apply and here is what we have: 64 Version 5.
Tutorial 2 - Modifying Selecting Planes Next we’ll add a floor composed of plate elements. We will use Criteria Selection to select the joints that we will draw to at the 10 foot elevation. This type of selection lets you select elevations, plans or any block of the model. Unselect the entire model by clicking on . Now click the Criteria Selection button. Select the Coordinates tab and click in the first Y coordinate field and enter “10” for the minimum value.
RISA-3D User’s Guide Click OK. Items at the 10 foot elevation are selected like this: Drawing Plates Now we can define the floor by drawing and submeshing plates. Click on the Draw / Modify Plates button. Leave the Material set to “gen_Conc3NW”. Then click in the Thickness field and change this to “3”. The dialog should look like this: Now click Apply to draw the plates. To start, click on the closest corner joint and then move to the right corner joint and click again.
Tutorial 2 - Modifying Submeshing Plates How many plate elements do you need to use to get accurate results? Entire texts can be devoted to the topic of “mesh size”. The finite element method is an “approaching method”. This means that finite elements give more accurate answers as you use a finer mesh of plates to model a given surface. See the RISA-3D General Reference for parametric studies that demonstrate this along with some design examples for shear walls, horizontal diaphragms and spread footings.
RISA-3D User’s Guide Click the Select All button and you should now see: Notice that submeshing the plates has added new joints along the existing beam members. These are automatically attached with the physical member feature. The plates are shown at 80%, which can be adjusted in the Plot Options. The shrink factors only apply to the length and width of the plates, not the thickness. The full thickness is always shown.
Tutorial 2 - Modifying These options control the graphic display of the plates and to a certain degree mimic the member display buttons. Wireframe, Color Filled, Rendered and Don’t Draw are the four main options across the top and are mutually exclusive. These determine how the plates are displayed. Beneath each of these are additional sub-options that may be included.
RISA-3D User’s Guide Model Merge Click on the Model Merge view to see this dialog: button on the Drawing Toolbar in the model In a nutshell, model merge looks for duplicate nodes and members (with the same coordinates) and merges them into one. If the “Merge crossing members?” option is checked in the model merge panel, RISA-3D will look for members crossing each other, and connect them. A typical case might be X-bracing.
Tutorial 2 - Modifying Change the X Factor to “1.25” and the dialog should look like this: Click Apply. The model view displays the change and we are finished widening the truss. We cannot use Scale feature to raise the truss because it would also lift the crossbeam. For this change we will use the Move feature. We will move the truss but we don’t want to move everything so we need make our selection first. It will be easier to work with an elevation so click on the Window toolbar.
RISA-3D User’s Guide Release the mouse button and the entire truss, and nothing else, should be selected. Now click the Move button on the Drawing Toolbar (it has a blue arrow) and a dialog appears. We only want to change the elevation so double-click in the field labeled Y and type “4.25”. Now click Apply. If we wanted to make the changes within the spreadsheets we could have used the block math feature to accomplish both modifications.
Tutorial 2 - Modifying We will now explain what you have in front of you, and what we have done. RISA-3D calculates most of these parameters for you although you may specify your own values as well. It is important to understand how each parameter is handled so you can take advantage of the capabilities of RISA-3D. Most fields have three labels separated by a slash (/), the first label is for steel, the second for timber, and the last one for concrete. Each field is described below.
RISA-3D User’s Guide Refer to the RISA-3D General Reference or On-line Help file for more information. The Cm factor, used in the calculation of the bending stress ratio for steel ASD design, may be entered if you wish to use a specific value. If left blank it will be calculated exactly by RISA-3D. CH shares the same column as Cmyy and is the NDS shear stress factor. If you leave the Cb factor blank RISA-3D will calculate it for you if you’re doing ASD design. For LRFD design, the Cb value is set to “1.
Tutorial 2 - Modifying Sorting Next up we will see how we can sort information in our model. Let’s look at the Joint Coordinates spreadsheet for the first time and let’s use a special window arrangement to do this. Click the Tiling button on the RISA Toolbar and the following list of window tiling options is presented. Later on we will experiment with these options. For now, select the second option which is “Joints Input” and click OK.
RISA-3D User’s Guide Click anywhere in the X-coordinate column. Click on the Window Toolbar, select “Sort Low to High” and click OK. The joints are now sorted in ascending X coordinate order. Now lets add a Zcoordinate sort. Click in the Z coordinate column. Click again and click OK. Last we will sort on the Y-coordinate. Click in the Y coordinate column. Click again and click OK.
Tutorial 3 - Loading Tutorial 3 – Loading In this tutorial we will load the model we defined in the last tutorial. Make sure you start off correctly by opening the file mentioned next. After starting RISA-3D click the Open File button. In the File Open dialog select the file named “RISA-3D Tutorial 3 Starter” and click Open. Close the Global Parameters window by clicking OK and we will begin working in the model view. Click to close the Data Entry Toolbar if it is open.
RISA-3D User’s Guide Type: Roof Load, [ENTER] Wind Load, [ENTER] Live Load, [ENTER] Dead Load, [ENTER] Cladding So we've given descriptions to five BLC's. These descriptions are strictly for your benefit. RISA-3D doesn't require a description. The rest of the spreadsheet is blank because we have no loads applied. We will apply the loads and then come back to this spreadsheet to discuss it further. Click to close the spreadsheet.
Tutorial 3 - Loading appropriate members. RISA-3D provides 1-way and 2-way area loads. 1-way loads are attributed to the closest member in a certain direction and 2-way loads are attributed to the closest member regardless of direction. The roof load will be a 20psf vertical load attributed to the truss top chords with a 1-way area load. The wind load will be a 40psf lateral load attributed to the members on the side of the structure with a 2-way area load.
RISA-3D User’s Guide Click OK. Items at the top chord elevation are selected like this: On the Insert menu select Area Load. Specify “-0.02” for the Magnitude. For the Distribution Direction select A-B from the drop down list. The case is already set to Roof Load so click Apply and we will draw the roof load area. For this 1-way area load the first two clicks define the direction of the load.
Tutorial 3 - Loading The maximum value is not necessary since there is nothing beyond that location. The dialog should look like this: Click OK. The front face elements are selected like this: Press Ctrl-D to define the area load. Change the Load Direction by selecting X from the drop down list. Specify “-0.04” for the Magnitude. For the Distribution Direction select Two Way from the drop down list. Change the case to Wind Load by selecting it from the drop down list.
RISA-3D User’s Guide Click on the bottommost node (N6) first and then proceed clockwise clicking on the corner nodes N84, N70 and finally N2 to define the area. Click Select All to select the entire model. Surface Loads The next thing we need to do is to put surface loads on the plates. We will apply a uniform .1ksf (100psf) load to all plates, as part of Basic Load Case 3. The surface load is applied uniformly over the surface of the plate.
Tutorial 3 - Loading Click Apply and the loads are created and displayed. Distributed Loads The cladding on the structure will be applied as a 300plf distributed vertical load on the BEAM-Z members. We will apply these loads by clicking on the members to demonstrate this method. Click the Distributed Loads button. Change the value in the Start Magnitude so that it reads “-0.3”. Notice how the value for the End Magnitude automatically defaults to this same value. Now click on the down Cladding”. Version 5.
RISA-3D User’s Guide Click Apply and we are ready to select the members. At this point we could simply click on the four BEAM-Z members to apply the load. However, for demonstration purposes, we will make a selection that designates the correct members. button and then click the Criteria Selection Click the Unselect All button. Click the Members tab and choose BEAM-Z from the Section Set list. Click OK and the members are selected in the view.
Tutorial 3 - Loading The Distributed Loads spreadsheet opens with the loads that were assigned to BLC 5. Note that the drop-down list on the left side of the active window now contains “BLC 5:Cladding”. To view distributed loads that belong to another BLC you can use this list to select the BLC of interest. You may also click on blank cells in the Basic Load Case spreadsheet to open spreadsheets for load cases that have yet to be defined.
RISA-3D User’s Guide We will use the Block Math feature to change the magnitude of the load. First we will select all of the cells in the Magnitude column. Click on the column heading for the Magnitude (this is the gray area at the top of the column that contains “Magnitude…”). The entire column is now selected and is colored magenta. Now click on the Block Math button to open the Block Math dialog. We want the dead load to be 90psf, or 90% of the copied live load. Enter “0.
Tutorial 3 - Loading Click in the next cell down which represents BLC 2 and select the down again and pick the “WL (Wind Load)” category. arrow In the same manner assign the third load case to the “LL (Live Load)” category and then assign BLC 4 and BLC 5 to the “DL (Dead Load)” category. The spreadsheet is complete and looks like this: Close it by clicking the in the titlebar. Load Combinations The last step in applying loads is to define how the loads are to be combined.
RISA-3D User’s Guide The combinations that were entered in the spreadsheet may be edited. We will explain all of the fields before going further. The first field, the description, is strictly for your reference. You may enter any descriptive label that you wish and it will be displayed with the results when the load combination is solved. The Solve checkbox indicates whether this combination is to be included in the Batch or Envelope solution.
Tutorial 3 - Loading These lines should now be shaded yellow. If they are magenta you selected cells in the spreadsheet, not the button on the very left. If you have selected the rows correctly the line delete button on the Window Toolbar should be active. Once you have the lines selected, click the Delete Lines Window Toolbar. button on the The lines are deleted leaving you with 10 combinations. Next we will delete combinations 9 through 10. You may also delete lines in a spreadsheet one at a time.
RISA-3D User’s Guide The remaining fields define which material types will be designed / checked for that load combination. This way we will never get an NDS wood code check for the strength level load combinations used for concrete design. Review the information in this screen to make sure the design data is the same as above, then close the spreadsheet by clicking the button. Displaying Loads Now click the Select All button to select the entire model. RISA-3D provides easy ways to view your loads.
Tutorial 3 - Loading Choose “LC 5:ASCE 3 (a)” from the drop down list. This is a great way to verify that our model is solving the problem that we want it to solve. One thing to note here is that the magnitudes of the loads represent the factored combination. For example the displayed floor load magnitude is the combination of the dead and live loads multiplied by their factors. When you are finished viewing the load combinations click the Switch Loads button once more to see loads by category.
RISA-3D User’s Guide Tutorial 4 – Solving & Results In this tutorial we will solve the model we defined in the last tutorial. Make sure you start off correctly by opening the file mentioned next. After starting RISA-3D click the Open File button. In the File Open dialog select the file named “RISA-3D Tutorial 4 Starter” and click Open. Close the Global Parameters window by clicking OK. Click to close the Data Entry Toolbar if it is open.
Tutorial 4 – Solving & Results Click Solve. RISA-3D reports the solution steps as they occur. When the solution is complete, you are presented with the Joint Reactions spreadsheet. You will notice that the reactions are summed at the bottom of the spreadsheet. The center of gravity of the vertical loads is reported in the last row. The Results toolbar is also opened for access to other results. You may view results in the spreadsheets, plotted on the model in the view, or in detail for each member.
RISA-3D User’s Guide Click in any cell in the last column, which is the z-z Moment column. Now click the Sort button on the Window Toolbar to access the sorting options. Select “Abs Max to AbsMin” and click OK. You'll be returned to the Forces spreadsheet with the members sorted according to their absolute maximum z-axis bending moment value. Select to view the member stresses. Select to view the torsional stresses, including warping normal and shear stresses for the members that warp.
Tutorial 4 – Solving & Results Graphic Results Since we've solved the model, we now have several more plotting options. First select Single View from the Window menu and the spreadsheets will be closed. Then turn off the joint labels by clicking toolbar by clicking the close button. . Finally, close the Results Plotting Deflected Shapes Click to open the Plot Options and select the Deflection Diagrams tab. Now select the option labeled “Load Combination” which will plot the combination we have solved.
RISA-3D User’s Guide Click OK on the Set Plot Options dialog to close it. The animation window is behind the model view window. From the Window menu select the last option which is “Animation of LC:7 ASCE 4 (a)” and the animation is brought back to the front. You may drag the window up to get a better view. Once the animation begins, you can speed it up or slow it down. This provides a very vivid presentation of how the model is deflecting.
Tutorial 4 – Solving & Results Click OK. The moment diagrams and reactions are plotted with magnitudes. Remember that the columns are bending about their weak axis, which would require a y-Moment plot to view those diagrams. Member Detail Report Next let's use the member detail report to take a closer look at some members. From the Results menu, select Members Member Detail. Click OK and you will get this report on member M1 which is the crossbeam on the back right: Version 5.
RISA-3D User’s Guide This report gives you the ability to see a detailed report showing all the forces, stresses and deflections for any individual member. You can expand any of these diagrams for closer inspection by clicking on them. Click on the local y-axis deflection diagram, the top diagram in the middle. You should now be looking at the deflection diagram for member M1. You may click the Abs Max button to retrieve the absolute maximum value and it’s location.
Tutorial 4 – Solving & Results Scroll down to view code check information and you will see the code check value along with the controlling equation and all of the design values. Finally, close the detail report by clicking the button. You may also open the member detail report by clicking on a member in the model view. On the Selection Toolbar click the Member Detail The mouse cursor will change to open the report. button.
RISA-3D User’s Guide The dialog should look like this: Click OK. You can see that the colored lines represent certain values of Mx and the contouring enables you to see graphically how the Mx moment is distributed on the floors. Next lets try the color filled contour. 100 Version 5.
Tutorial 4 – Solving & Results Click to get back to the plot options for the Plates. Now select Color Filled and the Contour option indented beneath it. Click OK. This gives a more colorful representation of the Mx distribution. Note that for the previous line contour each line represented a specific value; for this color fill contouring the colors represent a range of values that are displayed in the legend.
RISA-3D User’s Guide Batch Solution The Batch solution solves multiple combinations, keeping the results for all of them. The results spreadsheets may then be organized either by load combination or by item. Click on the Solve button again and this time choose Batch solution. Click Solve. You will be warned that the results will be cleared. Select Yes.
Tutorial 4 – Solving & Results Click on the Concrete Columns tab. The column design results are similar to the beam, except that the bending and shear results are given for biaxial loads. Click on the button located on the window toolbar. This will bring up an envelope detail report for the concrete column that looks similar to the one shown below: Because this detail report is based on moment and shear envelopes, it is somewhat different that the one we looked at for a steel member.
RISA-3D User’s Guide Code Check Results Click on the Tiling button, select Member Steel Results and click OK. The first things you will notice are the red members in the model view indicating that we have members that are failing. Notice that the spreadsheet results are now reporting the “worst case” results as a result of the envelope solution we ran. The columns labeled “lc” report the load combination that generated the controlling values.
Tutorial 4 – Solving & Results Now, we’d like to sort our results based on the maximum code check to see which members are closest to failure. Click anywhere in the code check column. Then click on the Sort button and select Sort Max to Min and click OK. Now look for the last member with a code check value that is 0.6 or higher which is M44 on the 5th line. Click anywhere in this row to place the active cursor like this: Now click on the Exclude After the Window Toolbar.
RISA-3D User’s Guide In the dialog above you can see that there are two other printing options. The first option will print lines from a spreadsheet and requires you to have selected the lines before you pressed Print . The last option will print an entire report. We will first exclude most of the items on our screen so that the report only requires a few pages.
Tutorial 4 – Solving & Results are in the report you may use the Up and Down buttons to adjust the printing order. We will remove a few items from the report before we print. Double-click on Story Drift, which is the fourth item in the Current Report. When you do this the section is removed from the report and placed back on the Available list.
RISA-3D User’s Guide Tutorial 5 – Dynamic Analysis In this tutorial we will perform a dynamic solution the model we updated in the last tutorial. Make sure you start off correctly by opening the file mentioned next. After starting RISA-3D click the Open File button. In the File Open dialog select the file named “RISA-3D Tutorial 5 Starter” and click Open. Close the Global Parameters window by clicking OK and we will begin working in the model view. Click to close the Data Entry Toolbar if it is open.
Tutorial 5 – Dynamic Analysis The dialog should look like the following figure: Click and the dynamic solution begins. The term “dynamic analysis” typically is taken to mean the analysis of a model for dynamic loading, including the calculation of stresses and displacements. For the purposes of RISA-3D, the analysis of a model for dynamic effects is considered to be composed of two parts.
RISA-3D User’s Guide You should be left with just this upper left model view: Now click on and then which will open the Plot Options dialog. Select the Joints tab. Clear the Show Joints checkbox. Click on the Deflection Diagrams tab and click on . You will get a warning that this may take a while (it shouldn’t for three modes). Click Yes. You will see three different progress bars, one after the other, build three different animations.
Tutorial 5 – Dynamic Analysis When you've finished viewing the animations select Single View from the Window menu. Response Spectra Analysis Click on the Solve Solve. button and select Response Spectra Analysis and click This brings us to the Response Spectra Selection window: The first field is a list of the available spectra in the RISA-3D spectra library. For this analysis, we'll have RISA-3D build a 97-UBC site-specific spectra. See Figure 16-3 in the UBC for the equations used to build the spectra.
RISA-3D User’s Guide For the tutorial we will have RISA-3D automatically detect and use the dominant mode (the mode with the highest participation factor, discussed later). Click on the down “Dominant”. arrow in the Mode for Signage field and select We will stick with the current combination method and damping ratio which are CQC and 5% respectively. So we've specified the spectra be applied in the X direction, and use the dominant mode for results signs. Click and the UBC 97 Spectra dialog is opened.
Tutorial 5 – Dynamic Analysis The procedure we use is based on the requirements in Section 1630 of ’97 UBC. If you are not familiar with these requirements or if you use another building code you will want to refer to the code to understand the basis for the procedure. The reasons for having to calculate scaling factors are twofold. First, if a “normalized” spectra was used to calculate the spectral results, you must scale the normalized results to match your site specific criteria.
RISA-3D User’s Guide for directional effects from RSA’s in two directions at the same time. An alternative to this method is an SRSS combination, which we will mention briefly. The SRSS flag indicates the RSA results from different directions are to be combined using an SRSS combination. This will generally ensure that reasonable maximum responses are obtained. Setting the SRSS flag will cause the RSA results to be ALL POSITIVES.
Conclusion Conclusion If you've completed the tutorials you should have a very good feel for how to use RISA-3D. Some of the topics we have not covered are listed below. You may not need all of these features but it is good idea to know they are available. Of course, if you wish to know more about specific features, you can refer to the RISA-3D General Reference or the On-line help system.
