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Complex Conditionals?
Posted Jan 26, 2016, 12:08 p.m. EST Parameters, Variables, & Functions 2 Replies
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I'd like to change some material properties mid-simulation, and I feel the best way to do this is through conditional statements that depend on time.
Is there a way to add a complex conditional statement, for example:
(if t>some number AND temp at some time was > some number)
Basically can I use the temperature of an element at certain times during the simulation in conditional statements?
Is there a way to add a complex conditional statement, for example:
(if t>some number AND temp at some time was > some number)
Basically can I use the temperature of an element at certain times during the simulation in conditional statements?
2 Replies Last Post Feb 1, 2016, 1:10 p.m. EST
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Posted:
9 years ago
Dear Richard,
You may find this article helpful:
www.comsol.com/blogs/tracking-material-damage-with-the-previous-solution-operator/
Best Regards,
You may find this article helpful:
www.comsol.com/blogs/tracking-material-damage-with-the-previous-solution-operator/
Best Regards,
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Posted:
9 years ago
Thanks Walter, I reviewed your link and I think this is what I need. I have some further questions.
I am wondering two things.
1. The previous solution and ODE&DAE features can be used to change parameters based on values from previous time step. In the example given, the emissivity was changed from E_undamaged to E_damaged if the temperature exceeded 60 degC. My question is can a material property, such as thermal conductivity, be changed from a function of temperature, to a different function of temperature? (These functions are interpreted from data but could be changed to analytical if necessary)
2. To change the emmisivity, logical statements were used:
the source term read...
emissivity-nojac(if(T>60[degC],E_damaged,emissivity))
which means if the temperature of an element exceeds 60C then emissivity should become E_damaged. I am wondering if I could include the elapsed time and the position of the elements in this logical statement. It would be something like if an element who's X-position is less than or equal to some function of time, AND the element's Y position is greater than equal to some constant, AND the temperature of that element is over 60C, then change some properties of the element.
Thanks a lot!
I am wondering two things.
1. The previous solution and ODE&DAE features can be used to change parameters based on values from previous time step. In the example given, the emissivity was changed from E_undamaged to E_damaged if the temperature exceeded 60 degC. My question is can a material property, such as thermal conductivity, be changed from a function of temperature, to a different function of temperature? (These functions are interpreted from data but could be changed to analytical if necessary)
2. To change the emmisivity, logical statements were used:
the source term read...
emissivity-nojac(if(T>60[degC],E_damaged,emissivity))
which means if the temperature of an element exceeds 60C then emissivity should become E_damaged. I am wondering if I could include the elapsed time and the position of the elements in this logical statement. It would be something like if an element who's X-position is less than or equal to some function of time, AND the element's Y position is greater than equal to some constant, AND the temperature of that element is over 60C, then change some properties of the element.
Thanks a lot!