Coupled thermo-structural analysis with LSDYNA

[mjie]

I am currently simulating an ultrasonic welding process with LSDYNA. I need to consider heat generation between the frictional surface and couple the heat flux with thermo-stress analysis. As the first step, I tried a simple model with just a few elemnets. I used mat#4, i.e. *MAT_ELASTIC_PLASTIC_THERMO, and assumed the material constants because I don't have reliable test data of aluminum. In running the model, I always get error message that the material is out of range, even if I tried in many ways to adjust the data.

Does somebody have the experience with LSDYNA thermo-structural analysis? Please give me help. Thanks a lot!

mjie

 

[gshye]

Hi,
I am doing some couple thermo-mechanical analysis, but I am using ABAQUS, the similar error occurs sometimes, I think the error is about too large displacement or distortion of the materials,right? so the methode to avoid that is to select the proper materials property data, such as thermal conductivity and specific heat.Also proper value of Young's modulus is also very important. Please also pay attention to the units you use for all these property data. Good luck!

 

[mjie]

You are right. When I increased the heat capacity (or specific heat?), the problem disappeared. Therefore, the problem is because that I used a too small heat capacity, which resulted in very sharp increasing of temperature.

If possible, can you please tell me the parameters you used in your simulation? I may need a further try. Thanks a lot!

mjie