Some problems like lights,relationshape between space and time, micro-electronics and so on.

Some problems like lights,relationshape between space and time, micro-electronics and so on.

Dear Rayudu Nithin Manohar, FEM is not working effectively when problems with infinite domain and high gradient of parameters  are solved. For example, in structural analysis, there is a contact problem  for interaction of rectangular die and elastic half-space when high concentration of contact pressures take place. FEM analysis of local stress-strain state of micro-heterogeneous  composite material is a difficult task too. In these cases we must choose analytical or semi-analytical  (boundary element method first of all) solutions which are more effective than FEM.

Good luck!

I have an interesting example of a harmonic Lamb wave propagating in an infinite isotropic plate. The analytical solution for the velocity dependence on frequency  is well known, it is called dispersion relation. However, my attemts to use FEM for launching Lamb wave at sufficiently large fequencies, failed due to necessity to decrease element size  with increasing frequency.