WS2B-1 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop 2B Assembly Contact Workbench-Mechanical Structural Nonlinearities

Workbench Mechanical – Structural Nonlinearities WS2B-2 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement Workshop 2B – Assembly Contact Goal: – In this workshop our goal is to investigate the behavior of the pipe clamp assembly (Pipe_clamp.x_t) shown here. Specifically we wish to determine the crushing stress and deformation in a copper pipe section when the bolt in the clamp is torqued down.

Workbench Mechanical – Structural Nonlinearities WS2B-3 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement We will assume the material used for the pipe is a copper alloy while all other parts are steel. It is assumed the clamp is torqued to 1000 N when placed in service. We’ll assume the coefficient of friction between the clamp and pipe is 0.4. The other contact regions will be treated as either bonded or no separation as shown in the accompanying figures. … Workshop 2B – Assembly Contact

Workbench Mechanical – Structural Nonlinearities WS2B-4 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement If previous workshop project is still in session, clear it from the project page Utility Menu > File >New… From the Toolbox, double click “Static Structural” to create a new system. 2.RMB the geometry cell and “Import Geometry and browse to “Pipe_Clamp.x_t” … Workshop 2B – Assembly Contact

Workbench Mechanical – Structural Nonlinearities WS2B-5 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement From the “Units” drop down menu: – Set Project units to “Metric (Tonne, mm, s, C, mA, N, mV). – “Display Values in Project Units” is checked (on). … Workshop 2B – Assembly Contact

Workbench Mechanical – Structural Nonlinearities WS2B-6 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement 3. 3.Double Click the “Model” cell to open the Mechanical Application 4.Once inside the Mechanical application, set the working unit systems “Unit>Metric(mm,kg,N,s,mV,mA)” 4. … Workshop 2B – Assembly Contact

Workbench Mechanical – Structural Nonlinearities WS2B-7 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement 5.Expand the “Connections” branch and use the shift key to highlight all contact definitions. 6.In the details window change the Formulation to “Augmented Lagrange … Workshop 2B – Assembly Contact

Workbench Mechanical – Structural Nonlinearities WS2B-8 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement 7.Highlight the first contact branch. This is the definition for the pipe to clamp contact. 8.In the detail for the definition change the Type to “Frictional”. 9.Enter a value for “Friction Coefficient” of … Workshop 2B – Assembly Contact

Workbench Mechanical – Structural Nonlinearities WS2B-9 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement 10.Highlight the second contact branch. This is the definition for the bolt shaft to clamp hole contact. 11.From the details window change the Type to “No Separation”. The remaining 2 contact regions will be modeled using the default bonded type of contact … Workshop 2B – Assembly Contact

Workbench Mechanical – Structural Nonlinearities WS2B-10 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement Create a local coordinate system along the pipe’s axis. Note, we will use the local coordinate system for post processing later. With the Coordinate system branch highlighted: 12. Select the inside surface of the cylinder. 13. “RMB > Insert > Coordinate System” … Workshop 2B – Assembly Contact

Workbench Mechanical – Structural Nonlinearities WS2B-11 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement 14.From the detail for the new coordinate system change “Type” to “Cylindrical”. 15.Change the Principal Axis to the “Z” Direction 16.Defined by “Geometry Selection” 17. “Click to Change” on Geometry, then select the inner surface of the pipe and “Apply” … Workshop 2B – Assembly Contact

Workbench Mechanical – Structural Nonlinearities WS2B-12 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement 18.In the Details of “Analysis Settings” Window, define the following: – Number of Steps = 2 – Large Deflection = On This analysis is run in two load steps. In, Load Step 1, apply the bolt pretension In Load Step 2, lock this pretension and postprocess the working load. … Workshop 2B – Assembly Contact

Workbench Mechanical – Structural Nonlinearities WS2B-13 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement 19.Select one of the end surfaces of the pipe. 20.Highlight “Static Structural” Branch RMB > Insert > Fixed Support … Workshop 2B – Assembly Contact

Workbench Mechanical – Structural Nonlinearities WS2B-14 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement 21.Select the cylindrical face of the bolt part. “RMB > Insert > Bolt Pretension” 22.In the Detail of “Bolt Pretension” window enter a “Preload” value of 1000 for “Load” Step 1. Using the Timeline, Set load step to “2” and define Pretension as “Lock” … Workshop 2B – Assembly Contact

Workbench Mechanical – Structural Nonlinearities WS2B-15 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement 23.Switch to “Body” select mode. 24.With Solution Branch highlighted, select the pipe part. 25.“RMB > Insert > Deformation > Directional” … Workshop 2B – Assembly Contact

Workbench Mechanical – Structural Nonlinearities WS2B-16 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement 26.From the detail for the “Directional Deformation” change to “Coordinate System”. Note we allowed the default name “Coordinate System” to be used when the local system was created. We could easily change the name to a more meaningful one. 26. … Workshop 2B – Assembly Contact

Workbench Mechanical – Structural Nonlinearities WS2B-17 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement 27.Switch to face select mode. 28.Highlight the outer surface of the pipe. 29.“RMB > Insert > Contact Tool 30. RMB Contact Tool in the Contact Tool Branch Insert > Pressure Repeat step 30 inserting contact “Frictional Stress”. Solve … Workshop 2B – Assembly Contact

Workbench Mechanical – Structural Nonlinearities WS2B-18 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement The solution for this workshop might take several depending on the available hardware. The use of frictional contact triggers a nonlinear solution requiring equilibrium iterations. The solution progress can be viewed by opening the “Solution Information” folder. … Workshop 2B – Assembly Contact

Workbench Mechanical – Structural Nonlinearities WS2B-19 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement Recall that the solution triggered the use of “Weak Spring” stabilization. To insure that the weak springs are not the result of rigid body motion, highlight the Environment branch and inspect the weak spring reaction forces. Highlight Solution, “RMB > Insert > Probe> Force Reaction and specify in the details window the boundary condition as “Weak Springs” – Verify that the reaction in the weak springs is of the order e-5, a negligible value. … Workshop 2B – Assembly Contact

Workbench Mechanical – Structural Nonlinearities WS2B-20 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement Highlight Solution. RMB > Insert > Probe > Bolt Pretension to verify that the bolt pretension working load equals user defined preload – In Details of Bolt Pretension, define Boundary as Bolt Pretension (Trivial since there is only one bolt in this model). – RMB > Evaulate Results … Workshop 2B – Assembly Contact

Workbench Mechanical – Structural Nonlinearities WS2B-21 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement Insert and plotting the “Total Deformation” for the assembly. – This plot is not particularly useful for our goal (investigation of pipe’s behavior). The “scoped” result we placed in the solution branch earlier will be more instructive. … Workshop 2B – Assembly Contact

Workbench Mechanical – Structural Nonlinearities WS2B-22 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement Highlight and plot the result “Directional Deformation”. In this case the result is scoped only to the pipe section. Also, since we employed a local cylindrical system at the pipe axis, the X direction here is displayed in the radial sense. … Workshop 2B – Assembly Contact

Workbench Mechanical – Structural Nonlinearities WS2B-23 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement Similarly, the behavior of the contact region can be view by highlighting the contact result objects. Again the use of scoped results allows a more intuitive plot of the quantity displayed. … Workshop 2B – Assembly Contact