Hello! I am experience a problem while picking Lorentz force from previous study.
I have a coil (domain 4) where i will ramp the current and a steel region (domains 2,5, 10, 11) where I'm trying to find stresses and deformations caused by Lorentz forces due to eddy currents induced in the steel. The rest is air.
I am ramping the current in the coil from maximum current to zero current, which induces eddy currents in yte steel region and should cause deformations in the steel region due to Lorentz forces.
I do: Study 1, Step 1: Coil Geometry analysis, with coil homogenized muti-turn, numeric feature. In mf/coil feature I prescribe Icoil=100[kA]-100[kA]*t, where t is defined as 0 in parameters. This works fine.
Study1, Step 2: Stationary - solves for magnetic field, t=0 This works fine.
Study 2: Step 1: time dependent - this is transient study where t changes from 0 to 1, reducing Icoil from 100kA to 0.. This seems to work also. I can see magnetic field changing with time, can plot induced currents in the steel region. In Study 1 and Study 2 only mf module is active.
Study 3, Step 1: stationary Here I activate solid mechanics module, but deactivate mf module. In solid mechanics body load is set to be Lorentz force force contribution(mf).
When I run this step it solves, however i doesn't pick up Lorentz forces and resulting stresses are zeros. I can't understand why Comsol at Study 3 doesn't pick Lorentz forces from the previous study. I tried to change body load from Lorentz forces to User Defined mf.FLtzx, mf.FLtzy, mf.FLtzz, but still Comsol doesn't pick the body load and resulting stresses are zeros. I have attached file with this model. can anyone please suggest me how to fix it?
Thanks!