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Dear all

I am using Structural Mechanics module to calculate the thermal stress in a two phase model (two differen materials). Under elastic node I have just added a thermal expansion node while I am simply avoiding the use of heat transfer and multiphysics coupling etc because the conduction is neglected, ie both the materils are cooled down at a same rate, there is no temerature gradient between the two materials (iso thermal domains) The questions is

how could I control the cooling rate and couple it with the solver time 't' ? At the end of calculation when I plot the temperature difference the comsol gives me the same value through out I'll try to be more specific solid.T 16°C solid.Tref 300°C and now during whole study time 't', the temp. difference is as following

• time Solid.Tref-Solid.T
• 0 284°C
• 10 284°C
• 20 284°C
• ------------

• 1000 284°C

  as a result of this, the stress state is almost same through the time step (0,10,1000). On the other hand I would like the temperature to drop slowly, say at a given rate which should be, in other words, the difference should rise gradually with time 't'

• time Solid.Tref-Solid.T

• 0 10°C
• 10 20°C
• 20 30°C
• ------------

• 1000 284°C

  so what I'll have at the end is that total stress state will be decomposed into many smaller ones, each of 'em being superimposed as the system progess over time...

  The help of community is much appreciated