hourglass controll - improve running time of jobs

[albert1981]

Dear all,

I am performing an analysis which is very long (at least 7 days) and needs to be improved.
I am modelling a quarter of the plate with a crack which is propagating from the centre with a very fine mesh and a cyclic load applied. The material is plastic.

There are any option in ABAQUS to increase the the speed of the jobs? Hourglass controll can help?

At the moment I am using shell element with a reduced integration S4R. I am using gaussian integration. Is not relly clear to me wheather hourglass controll can improve the performance. I am also using contact element to avoid compenetration in the symmetry line where the crack is propagating. Does anybody know if there are also option in the contact in order to increase the time performance?

Thanks in advance,

Albert

 

[gurmeet2003]

albert1981,

Hourglassing is a phenomenen that creates an artifical stress field on the top of the real field. Therefore you see geometric stress patterns that do not have any physical basis.

Hourglassing causes problem in accuracy. The way to check for hourglassing is to look at the aritificial energy and compare it to strain energy. The ratio should not exceed 1%. I do not think that hourglassing affects the speed of the solution. First thing to do would be to check if you have any hourglassing or not.

Gurmeet