2 Replies Latest reply on Feb 14, 2018 3:55 AM by Daniel Beaulieu

    Thermal Stress caused by Coefficient of Thermal Expansion

    Daniel Beaulieu

      Hi All,

      I am currently trying to run a simulation to predict thermal stress in a matrix & fibre composite with a change in temperature whilst cooling. My analysis runs and gives values but I know from the theory that the inner material should give a negative reading and then as it transitions through to the outside material it will become positive due to the difference in coefficient of thermal expansion of the two materials. Unfortunately I don't get a compressive stress value from the inner material!  

       

      If anyone could shed some light on why my model wouldn't show this that would extremely helpful!!

       

      I've attached some pictures for visual explanation.

       

      Cheers

        • Re: Thermal Stress caused by Coefficient of Thermal Expansion
          Attilio Colangelo

          Hi Daniel,

           

          A few comments:

          - It looks like you have a fixture at the interface between the outer and inner cylinder.  This is not valid, the model should be bound only at the boundary of the outer cylinder and use soft springs to stabilize further. 

          - Make sure you have applied the temperature to both parts/bodies, not just faces.  You will need to turn on "Solid Bodies" filter to be able to select them in the temperature dialog.

          - Since the effect you are looking for is "hoop" or radial stress keep this in mind when you are plotting x,y,z stresses. 

            • Re: Thermal Stress caused by Coefficient of Thermal Expansion
              Daniel Beaulieu

              Hi Attilio,

               

              Thanks for your quick response!

               

              So I adjusted all of the the points you have made, I have attached the results below. I am now seeing a negative value on the inner cylinder but it doesnt translate through the entire model as you can see but when I fix the other side it becomes rigid and goes back to the original result I posted?  I can see that if I section the model I get the visual result I am looking for but i need this to be correct across the full model.Any other suggestions?

               

              Thanks for your help

               

              Solidworks 2.PNG

              Image 1 - Adjusted Result

              Solidworks 3.JPG

              Image 2 - Section View