Example 10.2-1 [Ansys Workbench/Thermal Stress and User Defined Result] A 50m long deck sitting on superstructures that sit on top of substructures is modeled by a box shape of size 20 x 5 x 50

m3. It is subjected to 80

oC at top surface and convection all lateral surfaces. The end surfaces are

fixed. The convection coefficient of air is given by 50 W/m2-

oC and the ambient temperature is 20

oC.

The material is Structural Steel. (a) Compute the thermal stress distribution. (b) When the yield stess

varies with temperature by , obtain the ratio of the

equivalent stress to the yield stess.

Figure 10.2.1-1 The model deck and typical bridge structure (Michigan Dept of Transportation) Solution.

[Project]

1. Add Static Thermal Analysis

[Geometry] 2. Sketching tab> create the section

3. Modeling tab >Extrude > Generate

[Model] 4. Click Steady-State Thermal analysis in Outline

5. Temperature > pick the top surface > Apply > enter the temperature

6. Convection > pick all lateral surfaces > Apply > enter the film coefficient and bulk temperature

7. Click Solution in Outline 8. Thermal > Temperature and Total Heat Flux

9. Solve

[Project] 10. Drag and drop Static Structural analysis on top of Solution cell. The Schematic Map appears as

11. Double click Model cell

[Model] 12. Click Static Structural in Outline

13. Imported Load from thermal analysis solution has been added

14. Supports > Fixed Support > pick both end surfaces > Apply

15. Add Total Deformation and Equivalent Stress in Solution

16. Solve 17. The Equivalent Stress appears as

18. Click Solution in Outline > click Worksheet on top menu bar

19. Scroll down to BFE and right click >Create User Defined Result

20. BFE is the name for temperature in Ansys and appears in Outline 21. Right click > Rename > change it to Y(T) > enter Expression of Y(T) using BFE for temperature

> change Identifier to YT > see the result of Y(T)

22. Right click Solution in Outline > Insert > User Defined Result > right click it and change the name to SMargin > In Details, enter Expression as SEQV/YT and Identifier = SMargin

23. See user defined SMargin as

Example 10.2.2-1 [CFX] A water tank has dimensions as shown below. The units are in MKS. The thickness is 0.1 m outward from the given dimensions. (a) Create the tank by Revolve on XYPlane

and the outlet pipe by Extrude on a new plane located at 10 m from XYPlane. Also, Blend with

Radius = 0.5 m on the edge between two surfaces. (b) Then, use Tools > Thin to create a thin

structure. Use the outward thickness = 0.05 m. (c) Use Fill option to fill the tank for fluid. (d) Based on the geometry just created, perform CFX analysis. (e) Use the CFX results to perform static stress

analysis based on the pressure due to the flow.

Figure 10.2.2-1 Water tank structure

Solution.

[Project]

1. Add Component System/Geometry

[Geometry] 2. Sketching tab> create the closed section for the tank with Polyline

3. Modeling tab > Revolve > pick the axis of rotation / Apply > Generate

4. Click XYPlane > New Plane > Transformation 1 = Offset Z, FD1 = 10 m > Generate 5. Sketching tab > create the circle

6. Modeling tab >Extrude > Direction = Reversed > Depth = To Next > Generate

7. Tools > Thin > ctrl + pick both top and exit surfaces > Details/Selection Type=Faces to Remove / Direction=Outward / Thickness = 0.05 m > Generate

8. Assume that user forgot to add the round around the joint edge. Tree Outline/right click Thin

feature just added > Insert > Fixed Radius > pick the joint edge/Apply and enter the radius in

Details > Generate

9. Tools > Fill > Extraction Type = By Cavity > pick all three surfaces (the blended surface is not

used in Fill) > Generate 10. Click Solid body created by Fill operation and see Fluid/Solid = Fluid

11. Select the Solid body> right click > Suppress (no need)

[Project]

12. Drag and drop Fluid Flow (CFX) in Analysis Systems (not in Component Systems that does not have Geometry) on Geometry cell

[Mesh]

13. Generate mesh and see as (right now, just accept the default mesh). User should try to use Inflation for mesh controls at inlet and outlet. See below the original and inflated meshes.

[Setup]

14. Double click Default Domain in Outline or right click and Edit

a. Basic Settings tab >Material = Water, Reference Pressure = 1 atm > OK

15. Boundary> enter a name “inlet” > OK

b. Basic Settings tab

Boundary Type = Inlet

Click Location > pick the top surface

c. Boundary Details tab

Mass and Momentum / Normal Speed = 1 m/s

d. OK

16. Boundary> enter a name “outlet” > OK a. Basic Settings tab

Boundary Type = Outlet

Click Location > pick the end surface of the pipe

b. Boundary Details tab

Mass and Momentum > Option = Average Static Pressure, Relative Pressure = 1 atm

c. OK

[Project] 17. Double click Solution

18. Define Run dialog appears >Start Run> see the convergence plot as

19. Close the Solution window > back to Project [Results]

20. The initial wireframe may show much. Double click Wireframe in Outline

a. Definition tab > drag the slider and make Edge Angle = 5 > Apply

21. Contour > OK (accept the default name) > double click the contour in Outline

a. Geometry tab > Variable = Pressure > Apply

b. Uncheck Wireframe in Outline (see above right)

22. Vector > OK for name > double click the vector in Outline

a. Geometry tab > Variable = Velocity

b. Symbol tab > Symbol Size = 2 (just adjust seeing the results) > Apply

23. Clip Plane > OK for name > double click the clip plane in Outline

a. Geometry tab > Method = YZ Plane, X = 0 m, check Flip Normal (depends on your

model orientation) > Apply

b. Right click in Graphics window > Clip Scene > select the clip plane (see above right)

24. Streamline > OK for name > double click the streamline in Outline

a. Uncheck all others in Outline not to display them excep the streamline

b. Geometry tab > accept all defaults > Preview Seed Points > Apply

[Project]

25. Right click Geometry component > Duplicate

26. Double click the copy of Geometry

a. Unsuppress solid body

b. Suppress the fluid body

27. Drag and drop Static Structural analysis on Geometry cell of copied Geometry 28. Drag Fluid Flow/Solution and drop it on Structural Analysis/Setup

[Static Structural / Model]

29. Click Static Structural in Outline 30. Supports > Fixed Support > pick the bottom surface > Apply

31. Right click Imported Load> Insert > Pressure

a. In Details, select three inner surfaces for Geometry> Apply b. CFD Surface = Default Domain Default

32. Add Total Deformation and Equivalent Stress in Solution

33. Solve

34. Right click in Graphics window > View > Front

35. New Section Pane > draw a vertical line through the pipe > rotate the results