Sorry professor, I do not understand. Do you mean that In the latest code, I changed the sign in front of all terms linear form, and no sign change in front of the terms in the bilinear form? But the results are wrong, right? Or, you mean that I should change the sign in front of all terms in the right linear form? Sorry Professor, I really do not understand your mean.
Go back to the files from The elasticity problem with "varf" - #8 by SHENG, and change only the + to - (and vice versa) in front of linear terms, not bilinear terms. If this still does not work, send your update file.
If this is not clear to your, linear terms are terms with no references to u1 or u2 whatsoever. Please take your time, read your code carefully. There is no magic here, try to understand what you are doing instead of switching signs randomly…
Ok, professor,
Many thanks for your patient help. I will do that according to your advice.
Best,
Liu