June 27, 2021 at 8:06 am
Yes, if we apply load gradually, it is possible that convergence can happen and for that bisection happens.
Yes, you are also right about element distortion. Element distortion messages are usually indicative of significant problems due to excessive loading or over-constraint. Solver initially tries to apply load gradually and try to eliminate the distortion. Bisection of the solution is performed automatically, but sometimes additional corrective measures will need to be taken to fix this problem.
Also, there is one more common situation when contact status changes abruptly. ÔÇ£Contact status changes abruptlyÔÇØ means that some contact elements unexpectedly changed from status ÔÇ£closedÔÇØ to status ÔÇ£far openÔÇØ (or vice versa). This may be due to large sliding or bodies contacting/separating suddenly. Mechanical will automatically bisect the solution if necessary.
Refer to below link for some other common issues when bisection can happen.