Unexpectedly high thermal stress

Please login with a confirmed email address before reporting spam

When temperature is increased from293.15 K to 294.15 K, thermal stress increases by more than an 10 times magnitude. I have taken materials whose CTE values are reasonably close, but the stress is still extremely sensitive to temperature. I have also defined the temperature dependent properties of materials. Side walls and bottom surface of the sensor is taken as fixed constraint while cavity & diaphragm surface is taken as free constraint.

Any suggestions on debugging this kind of thermal-stress explosion would be greatly appreciated.



1 Reply Last Post 2026年2月25日 GMT+1 10:14
Henrik Sönnerlind COMSOL Employee

Please login with a confirmed email address before reporting spam

Posted: 2 days ago 2026年2月25日 GMT+1 10:14

From the picture, it looks like you have a singularity along the upper edge, so that the stresses can become arbitrarily large.

Without a singularity, a quick estimate of the stress increase for one degree temperature increase in a constrained structure is Young's modulus multiplied with the CTE. For a steel, for example, that number is of the order of 2-4 MPa / degree.

-------------------
Henrik Sönnerlind
COMSOL
From the picture, it looks like you have a singularity along the upper edge, so that the stresses can become arbitrarily large. Without a singularity, a quick estimate of the stress increase for one degree temperature increase in a constrained structure is Young's modulus multiplied with the CTE. For a steel, for example, that number is of the order of 2-4 MPa / degree.

Reply

Please read thediscussion forum rulesbefore posting.

Pleaselog into post a reply.

Note that while COMSOL employees may participate in the discussion forum, COMSOL®software users who are on-subscription should submit their questions via theSupport Centerfor a more comprehensive response from the Technical Support team.

Baidu
map