Learning Forum

[MToTheE]

I want to simulate the cooling of a wooden block and the tension which comes with it.

As first I simulate with the Transient Thermal components the cooling of a block from 20°C to -200°C. Thats totally working fine. Then I import the loads from the thermal expansion coefficient into the Static Structural components. When I now try to simulate this I get following error multiple times:

 *** ERROR ***                          CP =     19.453  TIME= 13:09:24

 Thermal strain in element 87626 with material 29 has caused the element  to invert. Please check the thermal expansion definition and the  temperature change.

The Zero-Thermal-Strain Reference Temperature, the Environmental Temperature and the Material Field Variables Temperature of all materials is set to 20°C because I read that they should be the same.

I also used Direct Solver and put the Force Convergence and Displacmenet Convergence on . Large Deflection is also put on because I read in a post that this all helps in simulations with extreme thermal phenomena.

I´m irritated a bit because I made some similar simulations befor and normally they worked. Maybe someone can help me out with a solution.

[peteroznewman]

If you want to see the thermal strain when the entire structure is at a uniform -200C, there is no need to perform a Transient Thermal. You can see the result of that uniform temperature using just a Static Structural analysis. Insert a Thermal Condition. In that load type the -200 C temperature.
Under Analysis Settings, you can have the End Time be 1 second, but turn on Auto Time Stepping. Set the Initial and Minimum Substeps to 100, Maximum to 1000. Turn on Large Deflection.

[MToTheE]

It┬┤s about the thermal strain resulting of an inhomogeneous distribution of the heat. The upper side get┬┤s cooled and the lower side stays at a defined temperature. So I want to know the distribution of heat about a long time period and also the stresses coming with to know at which time the block will get cracks. Thanks for youre help!