1. Large Deflection Arched Beam Workshop 7 Nonlinear Analysis

2. Workshop Supplement October 30, 2001 Inventory #001572 W7-2 7. Nonlinear Analysis - Large Deflection Arched Beam Description A shallow arch is subjected to a 20,000N force at its midspan. Determine the midspan displacement using both a linear and nonlinear (large-deflection) analysis, then compare the results.

3. Workshop Supplement October 30, 2001 Inventory #001572 W7-3 7. Nonlinear Analysis - Large Deflection Arched Beam Loads and Material Properties

4. Workshop Supplement October 30, 2001 Inventory #001572 W7-4 7. Nonlinear Analysis - Large Deflection Arched Beam 1.Enter ANSYS in the working directory specified by your instructor using “beamarch” as the jobname. 2.We recommend building the model using steps 3-12, but if you don't want to, you may resume an existing database (beamarch.db1), then skip to step 13. –Utility Menu > File > Resume from … –Or issue: RESUME,beamarch,db1 3.Define 4 keypoints in the global cylindrical system: kp1 at (1270,75), kp2 at (1270,90), kp3 at (1270,105), kp4 at (1270sin45, 90). Kp4 is the orientation keypoint. –Utility Menu > WorkPlane > Change Active CS to > Global Cylindrical –Main Menu > Preprocessor > -Modeling- Create > Keypoints > In Active CS … –Utility Menu > Parameters > Angular Units... –Or issue: /PREP7 CSYS,1 K,1,1270,75 K,2,1270,90 K,3,1270,105 *AFUN,DEG K,4,(1270*SIN(45)),90

5. Workshop Supplement October 30, 2001 Inventory #001572 W7-5 7. Nonlinear Analysis - Large Deflection Arched Beam 4.Define lines (arcs) from keypoints 1 to 2 and keypoints 2 to 3: –Main Menu > Preprocessor > -Modeling- Create > -Lines- Lines > In Active Coord + –Or issue: L,1,2 L,2,3 5.Define the element type to be BEAM189, and then define material properties (EX=210e3 MPa, PRXY=0.3): –Main Menu > Preprocessor > Element Type > Add/Edit/Delete … –Main Menu > Preprocessor > Material Props > Material Models …Structural – Linear – Elastic - Isotropic –Or issue: ET,1,BEAM189 MP,EX,1,210E3 MP,PRXY,1,0.3 6.Constrain the UX, UY, and UZ directions at keypoints 1 and 3, and then constrain only the UZ direction at keypoint 2: 6.Main Menu > Preprocessor > Loads > -Loads- Apply > -Structural- Displacement > On keypoints + –Or issue: DK,1,UX,0,,,UY,UZ DK,3,UX,0,,,UY,UZ DK,2,UZ,0

6. Workshop Supplement October 30, 2001 Inventory #001572 W7-6 7. Nonlinear Analysis - Large Deflection Arched Beam 7.Apply a force of 20,000 N in the negative Y direction at keypoint 2: –Main Menu > Preprocessor > Loads > -Loads- Apply > -Structural- Force/Moment > On keypoints + –Or issue: FK,2,FY,-20000

7. Workshop Supplement October 30, 2001 Inventory #001572 W7-7 7. Nonlinear Analysis - Large Deflection Arched Beam 8.Define the beam's section properties: –Main Menu > Preprocessor > Sections > -Beam- Common Sectns.. ID = 1 Sub-Type = Offset = Centroid B = 25 H = 12.5 [OK] –Or issue: SECTYPE,1,BEAM,RECT SECOFFSET,CENT SECDATA,25,12.5

8. Workshop Supplement October 30, 2001 Inventory #001572 W7-8 7. Nonlinear Analysis - Large Deflection Arched Beam 9.Assign attributes, including the orientation keypoint, to the lines: –Main Menu > Preprocessor > -Attributes- Define > All Lines... MAT = 1 TYPE = “1 BEAM189” SECT = 1 Pick Orientation Keypoint(s) = “yes” [OK] Pick keypoint 4, then [OK] –Or issue: LATT,1,,1,,4,,1

9. Workshop Supplement October 30, 2001 Inventory #001572 W7-9 7. Nonlinear Analysis - Large Deflection Arched Beam 10.Set 10 element divisions on all lines: –Main Menu > Preprocessor > -Meshing- Size Cntrls > -ManualSize- -Lines- All Lines... –Or issue: LESIZE,ALL,,,10 11.Mesh all the lines: –Main Menu > Preprocessor > -Meshing- Mesh > Lines + –Or issue: LMESH,ALL 12.Turn /ESHAPE on and set /EFACET to two, and then plot the elements: –Utility Menu > PlotCtrls > Style > Size and Shape... –Or issue: /ESHAPE,1 /EFACET,2 EPLOT

10. Workshop Supplement October 30, 2001 Inventory #001572 W7-10 7. Nonlinear Analysis - Large Deflection Arched Beam 13.Save the database and obtain the linear solution: –Pick the “SAVE_DB” button in the Toolbar (or select: Utility Menu > File > Save as Jobname.db) –Main Menu > Solution > -Solve- Current LS –Or issue: SAVE /SOLU SOLVE 14.Select node number 2 (mid-span node), then enter POST1 and print the nodal displacements: –Utility Menu > Select > Entities... –Main Menu > General Postproc > List Results > Nodal Solution... –Or issue: NSEL,S,,,2 /POST1 PRDISP

11. Workshop Supplement October 30, 2001 Inventory #001572 W7-11 7. Nonlinear Analysis - Large Deflection Arched Beam 15.Select everything and enter the solution processor to solve the nonlinear solution: –Utility Menu > Select > Everything –Main Menu > Solution > Sol’n Control.. Activate “Large Displacement Static” under Analysis Options Set Number of substeps = 10 [OK] –Main Menu > Solution > -Solve- Current LS –Or issue: ALLSEL /SOLU NLGEOM,1 NSUBST,10 SOLVE Convergence Graph

12. Workshop Supplement October 30, 2001 Inventory #001572 W7-12 7. Nonlinear Analysis - Large Deflection Arched Beam 16.List the displacement of node 2: –Utility Menu > Select > Entities... –Main Menu > General Postproc > List Results > Nodal Solution... –Or issue: NSEL,S,,,2 /POST1 PRDISP

13. Workshop Supplement October 30, 2001 Inventory #001572 W7-13 7. Nonlinear Analysis - Large Deflection Arched Beam 17.Select everything and set displacement scaling to 5, then plot the UY displacement results: –Utility Menu > Select > Everything –Utility Menu > PlotCtrls > Style > Displacement Scaling … –Main Menu > General Postproc > Plot Results > -Contour Plot- Nodal Solu … –Or issue: ALLSEL /DSCALE,1,5 PLNSOL,U,Y

14. Workshop Supplement October 30, 2001 Inventory #001572 W7-14 7. Nonlinear Analysis - Large Deflection Arched Beam 18.Animate the UY displacement results: –Utility Menu > PlotCtrls > Animate > Deformed Results … –Or issue: ANCNTR,10,0.5 19.Save and exit ANSYS: –Pick the “QUIT” button in the Toolbar –Or issue: FINISH /EXIT