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Thermal stress in a multilayer object
Posted 14 mar 2013, 06:25 GMT-4 1 Reply
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Hi.
Im trying to simulate the residual stress in a multimaterial sandwich structure and I have done it with the thermal stress module and with a time-dependant study.
I put all my doamins at an initial temperature of 100 °c, then I leave cool down by convection at 0°C. Every ten second I have the result for the Von Mises stress within my structure, in order to understand whether this stress reach the strenght of materials themselves.
Instead of finding that the stress increase as the temperature lowers (due to different thermal contraction), it results that the stress decreases in all layers.
1)Why?
2) What for, in case of a stationary study with steady temperature (T_initial=T_final), the stress is not zero?
Thanks to them can help me.
Im trying to simulate the residual stress in a multimaterial sandwich structure and I have done it with the thermal stress module and with a time-dependant study.
I put all my doamins at an initial temperature of 100 °c, then I leave cool down by convection at 0°C. Every ten second I have the result for the Von Mises stress within my structure, in order to understand whether this stress reach the strenght of materials themselves.
Instead of finding that the stress increase as the temperature lowers (due to different thermal contraction), it results that the stress decreases in all layers.
1)Why?
2) What for, in case of a stationary study with steady temperature (T_initial=T_final), the stress is not zero?
Thanks to them can help me.
1 Reply Last Post 20 mar 2013, 06:41 GMT-4
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Posted:
1 decade ago
Hi
have you checked the Strain reference temperature ? if your system is stress released at high temperatures, then you need to set the ref temp to the high value, and then you will see the stress build-up on cooling
often you get some residual stress as you need to wait very long to remove all heat from your bar, you see a "large" deformation scaled up to be shown, but in absolute it might well be only nanometres
By the way you could compare TS and HT+ Solid with Thermal expansion, there is a little difference, about 1% not sure why
--
Good luck
Ivar
have you checked the Strain reference temperature ? if your system is stress released at high temperatures, then you need to set the ref temp to the high value, and then you will see the stress build-up on cooling
often you get some residual stress as you need to wait very long to remove all heat from your bar, you see a "large" deformation scaled up to be shown, but in absolute it might well be only nanometres
By the way you could compare TS and HT+ Solid with Thermal expansion, there is a little difference, about 1% not sure why
--
Good luck
Ivar