Hello, I'm using COMSOL 4.3b for simulating a laser-material interaction, and I have predefined several parameters for specifying material's physical properties such as material's density, material's thermal conductivity, etc. with temperature dependence (interpolation function), which I run no problems at all.
However I've found out, according to the simulation result, these properties couldn't be changed permanently. Take the material density for an example*, the material's density changes with increased temperature as a result of absorption to laser induced energy, which is correct, however it changes back to original value when material cools down after laser beam moves away, which is physically incorrect as the material's composition has changed, which led a permanent density change, so the density value shouldn't be supposed to return back.
* rho v.s T is plotted as: farm8.staticflickr.com/7316/9580528024_451830a09c.jpg
Therefore may anyone could kindly offer any advice(s) for suggesting how I can specify a one-way directional relationship for making sure that a predefined physical property ONLY changes with INCREASING temperature please? In other words, reverse change is forbidden. (in this case, density reduction with decreasing temperature is not allowed)
Thanks!
P.S. I have thought about an alternative, which I can convert these physical properties to time-dependent values, based on a good assumption that could fix the model.
However I've found out, according to the simulation result, these properties couldn't be changed permanently. Take the material density for an example*, the material's density changes with increased temperature as a result of absorption to laser induced energy, which is correct, however it changes back to original value when material cools down after laser beam moves away, which is physically incorrect as the material's composition has changed, which led a permanent density change, so the density value shouldn't be supposed to return back.
* rho v.s T is plotted as: farm8.staticflickr.com/7316/9580528024_451830a09c.jpg
Therefore may anyone could kindly offer any advice(s) for suggesting how I can specify a one-way directional relationship for making sure that a predefined physical property ONLY changes with INCREASING temperature please? In other words, reverse change is forbidden. (in this case, density reduction with decreasing temperature is not allowed)
Thanks!
P.S. I have thought about an alternative, which I can convert these physical properties to time-dependent values, based on a good assumption that could fix the model.