I use COMSOL 4.3b to solve the problem of acoustic waves propagating in solid /air(water) with Eigenfrequency study/ Frequency domain studies. The solid-acoustic interaction need be considered in the simulations.
Everything work well for both eigenfrequency and frequency domain study, when the initial stress is not added in the linear elastic materials, which means that the geometrical nonlinearity is not considered.
When initial stress is added in the linear elastic materials and the 'including geometrical nonlinearity' below the study node is also selected, for simple structure, COMSOL also can obtain right results in both eigenfrequency/frequency domain studies. However, for some complex structures, COMSOL can not get a solution and usually return the message "failed to find a solution, ***, without convergency". Even without the message, the obtained results are obviously wrong, such as outlet power/inlet power > 1.
Is there some tricks in the solver setting, that can improve the convergency problem to get the correct solutions. It is hunting me for a long time.
Everything work well for both eigenfrequency and frequency domain study, when the initial stress is not added in the linear elastic materials, which means that the geometrical nonlinearity is not considered.
When initial stress is added in the linear elastic materials and the 'including geometrical nonlinearity' below the study node is also selected, for simple structure, COMSOL also can obtain right results in both eigenfrequency/frequency domain studies. However, for some complex structures, COMSOL can not get a solution and usually return the message "failed to find a solution, ***, without convergency". Even without the message, the obtained results are obviously wrong, such as outlet power/inlet power > 1.
Is there some tricks in the solver setting, that can improve the convergency problem to get the correct solutions. It is hunting me for a long time.