Analysis of an I-Beam Frame using Abaqus

New topics covered

• Create a part starting with a reference point
• Create datum planes and datum lines
• Create beam elements in 3D using the ‘Create Lines: Connected’ and ‘Create Wire: Point to Point’ tools
• Create beam sections and define beam profile geometry
• Orient beams and render the orientations in the viewport
• Use connectors (wire features + connector sections) to create joints
• Use constraint equations to simulate joints
• Use line loads

Overview

In this tutorial I analyze a 3D structure made of I-beams.

Loads will be applied on some of the beams. The bottom of the structure is fixed in such a way that it cannot translate but it is free to rotate.

Here are the dimensions of the structure:

The beams are I-beams with the following cross sectional profile:

I will use both join connectors and constrain equations to create the pin joints between the frames and cross members in order to demonstrate both methods. 

We will mesh the structure using shear-flexible (Timoshenko) beam elements.

Procedure

a. Overview

B. Part 1

C. Part 2

D. Part 3

Procedure In Text Form

This is a text version of the steps followed in the videos above. (To understand why these steps were followed please watch the videos with the sound turned on).

1. Rename Model-1 to Beam Frame
   • Right-click on Model-1 in Model Database
   • Choose Rename..
   • Change name to Beam Frame
2. Create the frame part
   • Double-click on Parts in Model Database. Create Part window is displayed.
   • Set Name to Frame
   • Set Modeling Space to 3D
   • Set Type to Deformable
   • Set Base Feature to Point
   • Set Type to Coordinates
   • Set Approximate Size to 20
   • Click Continue.. You see the message Enter the coordinates of the point displayed below the viewport
   • Type in 0.0,0.0,0.0 and hit the “Enter” key on your keyboard. A reference point marked with an X and the letters RP appears in the viewport.
   • Click on the Create Datum Point: Offset From Point tool in the toolbar. You see the message Select a point from which to offset displayed below the viewport.
   • Click on the reference point. You see Offset (X, Y, Z) displayed below the viewport. Type in 13.0,0.0,0.0 and hit the “Enter” key on your keyboard.
   • Click on Autofit view on the View Manipulation toolbar to see the point
   • You again see the message Select a point from which to offset displayed below the viewport.Again click on the reference point.
   • You see Offset (X, Y, Z) displayed below the viewport. Type in 4.0,-3.0,0.0 and hit the “Enter” key on your keyboard.
   • You again see the message Select a point from which to offset displayed below the viewport.Again click on the reference point.
   • You see Offset (X, Y, Z) displayed below the viewport. Type in 1.0,0.0,0.0 and hit the “Enter” key on your keyboard.
   • Click on the Create Datum Plane: 3 Points tool in the toolbar. You see the message Select the first point in the datum plane displayed below the viewport
   • Click on the point on the left. You see the message Select the second point in the datum plane displayed below the viewport.
   • Click on the point in the middle which is lower than the other two. You see the message Select the third point in the datum plane displayed below the viewport.
   • Click on the point on the right.
   • Click on Autofit view on the View Manipulation toolbar to see the plane.
   • Click on the Create Datum Axis: Principal Axis tool in the toolbar.
   • From the Principal axis choice buttons at the bottom of the viewport click on Y-Axis. The Y-axis is displayed in the viewport
   • Click on the Create Wire: Planar  tool in the toolbar. You see the message Select a plane for the planar wire displayed below the viewport
   • Click on the edge of the plane in the viewport. You see the message Select an edge or axis that will appear vertical and on the right displayed below the viewport.
   • Change the selection in the dropdown list to vertical and on the left
   • Click on the datum axis (the Y-axis) in the viewport. You enter the sketcher.
   • Use the Create Lines:Connected  tool to draw the profile of one frame
   • Split the lines using the Split tool
   • Use the Add Dimension tool to set the required dimensions
   • Click Done to exit the sketcher
   • Click on the Create Datum Plane: Offset from Plane  tool in the toolbar. You see the message Select a plane from which to offset displayed below the viewport
   • Click on the plane.You see the message How do you want to specify the offset? displayed below the viewport.
   • Click on Enter Value
   • You see the message Arrow shows the offset direction displayed below the viewport. You may wish to use the Rotate View tool from the View Manipulation toolbar to rotate the view so you can better see which way the arrow is pointed. It should be pointed along the positive Z axis (out of the screen, towards you)
   • Click OK
   • For Offset type in 1.5 and hit the “Enter” key on your keyboard. A second plane appears 1.5 m in front of the original. We can now draw the second frame on this.
   • Click on the Create Datum Point: Enter Coordinates tool in the toolbar. You see the prompt Coordinates for datum point (X, Y, Z) displayed below the viewport
   • Type in 1.0,0.0,1.5 and hit the “Enter” key on your keyboard
   • Then type in 13.0,0.0,1.5 and hit the “Enter” key on your keyboard
   • Then type in 4.0,-3.0,1.5 and hit the “Enter” key on your keyboard
   • Click on the Create Wire: Planar  tool in the toolbar. You see the message Select a plane for the planar view displayed below the viewport
   • Click on the new plane. You see the message Select an edge or axis that will appear vertical and on the right displayed below the viewport
   • Change the selection in the dropdown list to vertical and on the left
   • Once again click on the datum axis (the Y-axis) in the viewport. You enter the sketcher
   • Use the Create Lines:Connected  tool to draw the profile of the second frame
   • Split the lines using the Split tool
   • Use the Add Dimension tool to set the required dimensions
   • Click Done to exit the sketcher
3. Create the cross bracing
   • Double-click on Parts in Model Database. Create Part window is displayed
   • Set Name to CrossBracing
   • Set Modeling Space to 3D
   • Set Type to Deformable
   • Set Base Feature to Point
   • Set Type to Coordinates
   • Set Approximate Size to 20
   • Click Continue.. You see the message Enter the coordinates of the point displayed below the viewport
   • Type in 0.0,0.0,0.0 and hit the “Enter” key on your keyboard. A reference point marked with an X and the letters RP appears in the viewport
   • Click on the Create Datum Point: Enter Coordinates tool in the toolbar. You see the prompt Coordinates for datum point (X, Y, Z) displayed below the viewport
   • Type in  1.0,0.0,0.0 and hit the “Enter” key on your keyboard
   • Then type in  1.0,0.0,1.5 and hit the “Enter” key on your keyboard
   • Repeat for 1.0,0.0,0.0, 1.0,0.0,1.5, 4.0,-3.0,0.0, 4.0,-3.0,1.5, 6.0,0.0,0.0, 6.0,0.0,1.5, 6.0,-3.0,0.0, 6.0,-3.0,1.5, 8.0,0.0,0.0, 8.0,0.0,1.5, 8.0,-3.0,0.0, 8.0,-3.0,1.5, 10.0,-3.0,0.0, 10.0,-3.0,1.5, 13.0,0.0,0.0, 13.0,0.0,1.5
   • Click on the Create Wire: Point to Point tool in the toolbar. TheCreate Wire Feature window is displayed
   • Set Add method to Disjoint wires
   • Click the Add button
   • You see the prompt Select the first point displayed below the viewport. You can either type in 1.0,0.0,0.0or click on it with the mouse.
   • You see the prompt Select the second point displayed below the viewport. You can either type in 1.0,0.0,1.5 or click on it with the mouse. A line is drawn connecting the two points. You are once again prompted to Select the first point
   • Repeat the process till all the cross braces have been drawn
   • Click Done. All the datum points selected are filled into the table in the Create Wire Feature window.
   • Check Create set of wires
   • Click OK.
4. Create the material
   • Double-click on Materials in the Model Database. Edit Material window is displayed
   • Set Name to AISI 1005 Steel
   • Select General > Density. Set Mass Density to 7872 (which is 7.872 g/cc)
   • Select Mechanical > Elasticity > Elastic. Set Young’s Modulus to 200E9 (which is 200 GPa) and Poisson’s Ratio to 0.29.
5. Assign Profiles
   • Double-click on Profiles in the Model Database. Create Profile window is displayed
   • Set Name to FrameProfile
   • Set Shape to I
   • Click Continue..
   • The EditProfile window is displayed
   • Set l to 0.075
   • Set h to 0.15
   • Set b1 to 0.12
   • Set b2 to 0.12
   • Set t1 to 0.02
   • Set t2 to 0.02
   • Set t3 to 0.04
   • Click OK
   • Double-click on Profiles in the Model Database. Create Profile window is displayed
   • Set Name to CrossProfile
   • Set Shape to I
   • Click Continue..
   • The EditProfile window is displayed
   • Set l to 0.06
   • Set h to 0.12
   • Set b1 to 0.11
   • Set b2 to 0.08
   • Set t1 to 0.01
   • Set t2 to 0.01
   • Set t3 to 0.02
   • Click OK
6. Assign sections
   • Double-click on Sections in the Model Database. Create Section window is displayed
   • Set Name to Frame Section
   • Set Category to Beam
   • Set Type to Beam
   • Click Continue… The Edit Section window is displayed.
   • Set Section Integration to During Analysis
   • Set Profile name to FrameProfile which we created earlier
   • In the Basic tab, set Material to AISI 1005 Steel which was defined in the create material step.
   • LeaveSection Poisson’s ratio atthe default of 0
   • Click OK.
   • Again double-click on Sections in the Model Database. Create Section window is displayed
   • Set Name to Cross Section
   • Set Category to Beam
   • Set Type to Beam
   • Click Continue… The Edit Section window is displayed.
   • Set Section Integration to During Analysis
   • Set Profile name to CrossProfile which we created earlier
   • In the Basic tab, set Material to AISI 1005 Steel which was defined in the create material step.
   • Leave Section Poisson’s ratio at the default of 0
   • Click OK
7. Assign the sections to the frame and cross bracing
   • Expand the Parts container in the Model Database. Expand the part Frame.
   • Double-click on Section Assignments
   • You see the message Select the regions to be assigned a section displayed below the viewport
   • Click and drag with the mouse to select the entire frame (both sides).
   • Click Done. The Edit Section Assignment window is displayed.
   • Set Section to Frame Section.
   • Click OK.
   • Click Done.
   • Expand the Parts container in the Model Database. Expand the part CrossBracing.
   • Double-click on Section Assignments
   • You see the message Select the regions to be assigned a section displayed below the viewport
   • Click and drag with the mouse to select the entire frame (both sides).
   • Click Done. The Edit Section Assignment window is displayed.
   • Set Section to Cross Section.
   • Click OK.
   • Click Done.
8. Define Beam Orientations
   • Change the Module (displayed above viewport) to Property if it isn’t already the case using the dropdown menu.
   • Using the menu bar click on Assign>Beam Section Orientation…
   • You see the message Select the regions to be assigned a beam section orientation displayed below the viewport
   • Click and drag with the mouse to select the entire crossbracing
   • Click Done. You see the prompt Enter an approximate n1 direction (tangent vectors are shown) displayed below the viewport.
   • Type in 1.0,0.0,0.0 and hit the “Enter” key on your keyboard. You notice orientation arrows have been displayed in the viewport. You see the prompt Click OK to confirm input  displayed below the viwport.
   • Click OK.
   • By default you may not be able to see how the beams are oriented in the viewport. Using the menu bar click on View>Part Display Options. The Part Display Options window is displayed.
   • In the General tab, in the Idealizations section, check Render beam profiles.
   • Click OK.You now see the cross beam profiles rendered in the viewport.
   • At the top of the viewport, ensure the Module is still set to Property and change the Part to Frame .
   • Using the menu bar click on Assign>Beam Section Orientation…
   • You see the message Select the regions to be assigned a beam section orientation displayed below the viewport
   • Click and drag with the mouse to select the entire frame (both sides)
   • Click Done. You see the prompt Enter an approximate n1 direction (tangent vectors are shown) displayed below the viewport.
   • Type in 0.0,0.0,1.0 and hit the “Enter” key on your keyboard. You notice orientation arrows have been displayed in the viewport. You see the prompt Click OK to confirm input  displayed below the viwport.
   • Click OK
   • You now see the cross beam profiles rendered in the viewport. You can now disable rendering of beam profiles.Using the menu bar click on View>Part Display Options. The Part Display Options window is displayed. In the General tab, in the Idealizations section, uncheck Render beam profiles. Click OK.
9. Create the Assembly
   • Double-click on Assembly in the Model Database. The viewport changes to the Assembly Module.
   • Expand the Assembly container.
   • Double-click on Instances. The Create Instance window is displayed.
   • Set Parts to Frame
   • Set Instance Type to Dependent (mesh on part)
   • Click Apply. The Frame is displayed in the viewport.
   • Set Parts to CrossBracing
   • Set Instance Type to Dependent (mesh on part)
   • Click OK. Now both Frame and CrossBracing are displayed in the viewport. Note that they are not actually connected together but only look that way since we created the parts in the correct locations.
   • If you wish to see the rendered beam profiles, using the menu bar click on View>Assembly Display Options. The Assembly Display Options window is displayed. In the General tab, in the Idealizations section, check Render beam profiles. Click OK. Disable the beam profile rendering by repeating the process and unchecking Render beam profiles.
10. Create the connector wires
    • Change the Module (displayed above viewport) to Interaction if it isn’t already the case using the dropdown menu
    • Click on the Create Wire Feature tool in the toolbar. The Create Wire Feature window is displayed
    • Set Add Method to Disjoint wires
    • Click the Add… button. You see the message Select the first point displayed below the viewport.
    • Click on the first point. You see the message Select the second point displayed below the viewport
    • Click on the same point again. You again see the message Select the first point displayed below the viewport
    • Repeat the procedure till 12 of the 16 nodes are selected. Do not select the 4 nodes of the second loop as we will demonstrate a different method for these.
    • Click Done. All the selected points are displayed in the list.
    • Ensure that Create set of wires  is checked
    • Click OK.
    • Expand the Assembly container in the Model Database. Expand the Sets container. You see Wire-1-Set-1. This is the set of connector wires we have just created. Right-mouse-click on it and choose Rename. The Rename Set window is displayed
    • Set the name to Set of connector wires
    • Click OK
11. Create connector sections
    • Double-click on Connector Sections in the Model Database. The Create Connector Section window is displayed
    • Set Name to FrameCrossConnSect
    • Set Connection Category to Basic
    • For Connection Type set Translation type to Join and leave Rotational type at the default of None. You will see Constrained CORM: U1, U2, U3
    • Click Continue…The Edit Connector Section window is displayed
    • Leave everything as it is and click OK.
12. Assign connectors
    • Expand the Assembly container in the Model Database. Double-click Connector Assignment. You see the message Select wires or attachment lines to be assigned a section displayed below the viewport
    • At the right of the message is a button Sets… Since we earlier assigned the connector wires to a set during their creation, we can use this. Click it. The Region Selection window is displayed
    • Choose Set of connector wires from the list.
    • Click Continue…The Edit Connector Section Assignment window is displayed
    • Set Section to FrameCrossConnSect
    • Click OK
13. Identify Sets for remaining 4 nodes
    • Expand the Assembly container in the Model Database. Expand the Instances container.
    • Right-click on Frame-1 and choose Suppress. Frame-1 becomes invisible.
    • Double-click on Sets. The Create Set window is displayed.
    • Set Name to crossnode1
    • Click Continue…You see the message Select the geometry for the set displayed below the viewport
    • Select one of the upper nodes of the crossbracing which was not used as a connector.
    • Click Done.
    • Once again double-click on Sets. The Create Set window is displayed.
    • Set Name to crossnode2
    • Click Continue…
    • Yousee the message Select the geometry for the set displayed below the viewport
    • Select the other upper node of the crossbracing
    • Click Done
    • Right-click on Frame-1 and choose Resume. Frame-1 becomes visible again
    • Right-click on CrossBracing-1 and choose Suppress. CrossBracing-1 becomes invisible
    • Double-click on Sets. The Create Set window is displayed.
    • Set Name to framenode1
    • Click Continue…You see the message Select the geometry for the set displayed below the viewport
    • Select the node on the frame which corresponds to crossbracing1
    • Click Done.
    • Once again double-click on Sets. The Create Set window is displayed.
    • Set Name to framenode2
    • Click Continue…
    • You see the message Select the geometry for the set displayed below the viewport
    • Select the node on the frame which corresponds to crossbracing2
    • Click Done
    • Right-click on CrossBracing-1 and choose Resume. CrossBracing-1 becomes visible again
14. Create constraints for the 4 nodes
    • Double-click on Constraints in the Model Database. The Create Constraint window is displayed
    • Set Name to JoinConstraint1
    • Set Type to Equation
    • Click Continue…
    • The Edit Constraint window is displayed
    • Set the values as displayed in Table 1
    • Click OK.
    • Repeat the process to create JoinConstraint2 (see Table 2), JoinConstraint3 (see Table 3), JoinConstraint4 (see Table 4), JoinConstraint5 (see Table 5) and JoinConstraint6 (see Table 6) with the following values in the respective tables
15. Create Steps
    • Double-click on Steps in the Model Database. The Create Step window is displayed.
    • Set Name to Apply Loads
    • Set Insert New Step After to Initial
    • Set Procedure Type to General >Static, General
    • Click Continue.. The Edit Step window is displayed
    • In the Basic tab, set Description to Loads are applied in this step.
    • Click OK.
16. Assign Loads
    • Double-click on Loads in the Model Database. The Create Load window is displayed
    • Set Name to CrossLoad1
    • Set Step to ApplyLoads
    • Set Category to Mechanical
    • Set Type for Selected Step to Line load
    • Click Continue…
    • The Region Selection window is displayed. You see the message Select a region from the dialog displayed below the viewport. However we wish to select the elements by clicking in the viewport. Click on Select in Viewport
    • You see the message Select bodies for the load displayed below the viewport. Select the crossbar by clicking on it.
    • Click Done.The EditLoad window is displayed
    • Set Component 2 to -1000.
    • Click OK.
    • You will see the force displayed with arrows in the viewport on the selected crossbrace
    • Repeat the process to create a line load on the adjacent cross bracing. Name the load CrossLoad2.
    • Repeat the process to create a line load on the frontal frame element. Name the load FrameLoad1. Set Component 2 to -1500
    • Repeat the process to create a line load on the frame element diagonally across from this one. Name the load FrameLoad2.Set Component 2 to -500
17. Apply boundary conditions
    • Double-click on BCs in the Model Database. The Create Boundary Condition window is displayed
    • Set Name to FixBottom
    • Set Step to Initial
    • Set Category to Mechanical
    • Set Types for Selected Step to Displacement/Rotation
    • Click Continue…
    • You see the message Select regions for the boundary condition at the bottom of the viewport. Click while pressing the “Shift” key on your keyboard to select all the elements (beams) at the base of the structure.
    • Click Done. The Edit Boundary Condition window is displayed.
    • Check off U1, U2 and U3. This will pin these beams allowing them to rotate but preventing any translational motion.
    • Click OK.
18. Create the mesh
    • Expand the Parts container in the Model Database.
    • Expand CrossBracing
    • Double-click on Mesh (Empty). The viewport window changes to the Mesh module and the tools in the toolbar are now meshing tools.
    • Using the menu bar click on Mesh > Element Type …
    • You see the message Select the regions to be assigned element types displayed below the viewport
    • Click and drag using your mouse to select all the crossbraces.
    • Click Done. The Element Type window is displayed.
    • Set Element Library to Standard
    • Set Geometric Order to Linear
    • Set Family to Beam
    • You will notice the message B31: A 2-node linear beam in space
    • Click OK
    • Click Done
    • Using the menu bar lick on Seed > Edge by Number
    • You see the message Select the regions to be assigned local seeds displayed below the viewport
    • Click and drag using your mouse to select all the cross braces
    • Click Done.
    • You see the prompt Number of elements along the edges displayed below the viewport.
    • Set it to 4 and press the “Enter” key on your keyboard
    • Click Done
    • Using the menu bar lick on Mesh > Part
    • You see the prompt OK to mesh the part? displayed below the viewport
    • Click Yes
    • Repeat the above process to mesh the frame as well.
19. Create and submit the job
    • Double-click on Jobs in the Model Database. The Create Job window is displayed
    • Set Name to BeamFrameAnalysisJob
    • Set Source to Model
    • Select BeamFrame (it is the only option displayed)
    • Click Continue.. The Edit Job window is displayed
    • Set Description to Analysis of loaded beam frame
    • Set Job Type to Full Analysis.
    • Leave all other options at defaults
    • Click OK
    • Expand the Jobs container in the Model Database
    • Right-click on BeamFrameAnalysisJob and choose Submit.
    • It is quite possible that you will get an error message stating that connector assignments reference regions are empty or have been deleted or suppressed. Click Dismiss
    • Expand the Assembly container in the model tree. Expand the Features container. You will find that Wire-1 has been crossed off. Right click on it and select Resume.
    • Try running the simulation again. This time it will run. You will see the following messages in the message window: 
      The job input file "BeamFrameAnalysisJob.inp" has been submitted for analysis. Job BeamFrameAnalysisJob: Analysis Input File Processor completed successfully
      Job BeamFrameAnalysisJob: Abaqus/Standard completed successfully
      Job BeamFrameAnalysisJob completed successfully

Table 1 - Join Constraint1

Table 2 - JoinConstraint2

Table 3 - JoinConstraint3

Table 4 - JoinConstraint4

Table 5 - JoinConstraint5

Table 6 - JoinConstraint6