Author(s): Sebastian Vecchi, ANSYS Inc.
Problem Specification
1. Pre-Analysis & Start-Up
2. Geometry
3. Mesh
4. Physics Setup
5. Results
6. Verification & Validation
Pre-Analysis & Start Up
Pre-Analysis
First, we need to know if the expansion of the bar is greater than the free space between the bar and the wall x = 0.002 meters. Below is the equation and the calculated result used for the expansion of the bar.
δT=αLT=(1.2E-5°C-1)(5m)(100° C)=0.006m >0.002m
Now that we know that the deformation due to the change in temperature will be greater than the space between the bar and the wall, we know that there will be a stress on the bar. If the wall was not there, the bar would fully deform to the calculated value above. Since the wall does stop the deformation process the following equation can be used.
δT=x+δσ
Where Tis the strain contribution from the change in temperature and is the strain contribution from the force imparted by the wall on the bar. This equation can be combined with the first one to make the following.
αLT=x+PL/EA
Substituting xx=PA, we get the solvable equation
αLT=x+σxx/LE
Solving for , we find that
σxx=αET-xE/L
After substituting, we find
σxx=(1.2E-5°C-1)(2E11 Pa)(100° C)-(0.002m)(2E11 Pa)(5m)=160 MPa
Start-Up
Now that we have the pre-calculations, we are ready begin simulating in ANSYS AIM. Open ANSYS AIM by going to Start > All Apps > ANSYS 18.1 > ANSYS AIM 18.1. Once you are at the starting page of AIM select the Thermal template in the top right corner as shown below.
You will be prompted by the Thermal Template to either Define new geometry, Import geometry file, or connect to active CAD session. Select define new geometry and press Next. For this problem we will be using a Steady/static calculation type and adding structural as an additional physic, select them in the menu and press Finish. The Model Editor will launch automatically.
Go to Step 2: Geometry