Problem 1: Structural Analysis of Signs Post University of Puerto Rico at Mayagüez Department of Mechanical Engineering Modified by (2008): Dr. Vijay K. Goyal Associate Professor, Department of Mechanical Engineering University of Puerto Rico at Mayagüez Thanks to UPRM students enrolled in INME 4058 sections

Scope The purpose of this problem is to demonstrate how to solve the displacements of a homogeneous multiple section hollow bar using ANSYS.

Problem Description A 20ft tall post is used to support advertisement signs at various locations along its height, as shown in the accompanying figure. The post is made of structural steel with a modulus of elasticity of E = 29X10 6 lb/in 2. Not considering wind loadings on the signs, (a) determine displacements of the post at the point of load application and (b) determine stresses in the post. OD T lb 150 lb 200 lb Set No.ODT In inches

Start up First, let’s start by opening ANSYS by: Click on: Start > All Programs > ANSYS > Product Launcher. The configuration window will appear: Here we will change the working directory and the memory settings.

Working Directory This is the 10.0 ANSYS Product Launcher main window. Select the Working Directory and type the name of work shop on Job Name.

Memory Settings This step is done for slow computers Click the button Customization/ Preferences. On the item of Use custom memory settings type 128 on Total Workspace (MB): and type 64 on Database (MB):. Then click the Run bottom. Memory settings

ANSYS Main Window This is the main window of ANSYS University Intermediate Utility Menu.

GUI Filtering In order to maximize your workspace to meet your needs. Let’s filter out the GUI (Graphical User Interphase). Click on Preferences > Choose on GUI Filtering: Structural > OK.

GUI Filtering Setting Preferences: 1. Click on Preferences on the ANSYS Main Menu window 2. Select Structural and h-method and Click OK 1 2 2

Element Type For ANSYS to properly analyze the problem, we must choose well the appropriate element. We will choose Element Type Pipe Elastic straight16:

Element Type 1. On Main Menu window, click Preprocessor \ Element Type \ Add/Edit/Delete 2. Click Add… on The Element Types Window 1 2

Element Type 3. On the Library of Element Type window select Pipe Elastic straight16 \ click OK \ click Close on the Element Type window 3

Real Constants The real constant are the dimensions that must remain constant during the design. These constants are: diameters, thickness, among others.

Real Constants 1. On the Main Menu Window select Preprocessor \ Real Constants \ Add/Edit/Delete. 2. On the Real Constants window, click add

Real Constants 1. On the Real Constants window, input the values of outer diameter and wall thickness and click apply. 2. Then enter the new Set No. and repeat the step 1 for each Set No. 3. Finally click ok. 1 Set No.ODT In inches 2

Real Constants Change the Real Constant Set No. Enter the New Outside Diameter and New Thickness 1 2 Then click Apply 3

Real Constants Enter the New Set No, Outside Diameter and Thickness Finally Click ok

Real Constants Click Close

Material Properties 1. On the Main Menu Window select Preprocessor \ Material Props \ Material Models. 2. On the Material Model Behavior window select Material Model Number 1 \ Structural \ Linear \ Elastic \ Isotropic 3. For EX enter 29e6 and in PRXY enter Finally Click Ok and close the material Model Behavior window

Geometry The strategy to create the desired geometry is by first creating the key points where the loads will be applied and then uniting these key points with lines.

Geometry 1. On the Main Menu Window select Preprocessor \ Modeling \ Create \ Keypoints \ In Active CS. 2. Enter the locations for all the nodes in the table. Then click OK. Note that all dimensions were converted to inches 1 2 KeypointXYZ Then Click Apply

Geometry Enter the New Key Point and It Location Then Click Apply

Geometry Enter the New Key Point and It Location Then Click Apply

Geometry Enter the New Key Point and It Location Finally click apply and then ok

Geometry 3. On the Main Menu Window select Preprocessor \ Modeling \ Create \ Lines \ Lines \ Straight Line. 4. Pick point 1 and then point Repeat process until all three lines are finished. 3 4

Geometry Pick First point 1 and then point 2 1 2

Geometry Pick Point 2 and then Point 3

Geometry Pick point 3 and then point 4 Finally Click Ok

Geometry 6. The final model should look like this: 6

Meshing To make the finite element analysis we must first divide the object into small elements, this is called meshing.

Meshing 1. On the Main Menu window, select Preprocessor \ Meshing \ MeshTool 2. On the MeshTool window Click on Smart Size \ Select 4 \ Select Mesh: Lines \ Click on Mesh

Meshing 3. Click on the material # 1 and then OK Material # 1 Click OK

Meshing 4. Click on: Plot > Lines to see the element.

Meshing 5. Click on: Set > Real Constant Set No. enter 2 > OK > Mesh Set Select 2 Mesh

Meshing 6. Click on the material # 2 and then OK Material # 2 Click OK

Meshing 7. Click on: Plot > Lines to see the element.

Meshing 8. Click on: Set > Real Constant Set No. enter 3 > OK > Mesh Set Select 3 Mesh

Meshing 9. Click on the material # 3 and then OK Material # 3 Click OK

Meshing 10. Close the “Mesh Tool” window Close

Loads & Displacements Now we are able to apply the loads at the key points and the boundary conditions of the element

Displacements 1. On Main Menu Window select Preprocessing \ Loads \ Define Loads \ Apply \ Structural \ Displacement\On Keypoints 2. Select the Keypoint Number 1 and click OK. 1 2

3. Select All DOF, and Apply as Constant Value with a Value of 0. Displacements 3

Loads 1. On Main Menu Window select Preprocessing \ Loads \ Define Loads \ Apply \ Structural \ Force/Moment \ On Keypoints 2. Select the Keypoint Number 2, choose FY and enter a value of -200 and then click OK. 1 Pick Point 2 and then click ok Enter the corresponding Values for the force

Loads 3. Repeat the previous procedure for the loads applied at the key points three and four. KeypointLoadDirection 2-200FY 3-150FY 4-100FY

Loads 4. The Model should look like this:

FEM Solution & Plotting Results Now we already developed the geometry, Loads & Displacements and the meshing. We will start with the finite element analysis and obtain the displacements on the key points. After make the FEM solution we are able to plot the results, in this case the displacements.

FEM Solution 1. On ANSYS Main Menu window select Solution \ Solve \ Current LS 1 Then click OK

FEM Solution Then a window will appear indicating that the solution is done. Next close the window.

Plotting Results 1. On Main Menu Window select General Postproc \ Plot Results \ Deformed Shape. 2. Select Def + undeformed 3. Click ok 2 1 3

Plotting Results 3. On Main Menu Window select General Postproc \ Plot Results \ Contour Plot \ Nodal Solu 4. Then DOF Solution \ Y-Component of displacement \ OK. Uy

Plotting Results 5. The plot for the Y-displacements should look like this:

Plotting Results Plotting Results for Stresses 1. On Main Menu Window select General Postproc \ Element Table \ Define Table 2. Click Add. 2 1

Plotting Results Plotting Results for Stresses 3. Select Stress \ von Mises Stress SEQV 4. Click OK. 4 3

Plotting Results Plotting Results for Stresses 5. On Main Menu Window select General Postproc \ Element Table \ Plot Elem Table. 6. Select SEQV and No – do not avg and click OK. 5 6

Plotting Results Plotting Results for Stresses 7. The plot for the Von Misses stresses should look like this: