I checked a simple tube with variable cross section for bending .
hand calculation states a max. stress of 312 MPa. the simulation show a max. stress of 1100 MPa.
the high stress is a "hot spot" format. if I refine the mesh, the stress result will go higher. in fact , a very coarse mesh gives closer results to reality.
how do I tackle these "hot spots"? it makes the whole simulation useless.