From: Lorenzo Zanon <zanon@ai...>  20131122 17:42:17

Hello, I have an example based on miscellaneous_ex3.C, where I implemented a nonlinear elastic problem with StVenant stressstrain law on a 3D domain 5x1x1, blocked at x=0 and with an applied load at x=5. The problem is, the computation of the displacement (along x y and z) is really slow (hours), on our cluster it goes out of CPU time already with a mesh of 64x8x1 (the loading acts only on the ydirection, so no more elements are needed along z). 4 or 5 Newton steps should be enough for solving the problem... A colleague of mine implemented the same problem on the software called FEAP, and it takes only a few minutes there. I think my implementation is correct because the results on a very coarse mesh (10x2x1) are roughly similar to the FEAP ones on a finer mesh. I don't have any problems for the 2D case also. Is there anything I can do? I'm running in opt mode with the following options concerning the Newton solver: snes_type ls snes_linesearch_type basic snes_mf_operator pc_type lu pc_factor_nonzeros_along_diagonal Thanks! Lorenzo 