Why can't I solve a harmonic magetic analysis with SOLID117 in ANSYS 8.1?
I could solve it in ANSYS 7.1.
|
You are running out of memory. Starting in 8.0 we added the ability to keep the database data in memory during solution. For this model that adds about 150 MB to the memory requirement 7.1. However, it saves about 20% elapsed time due to less I/O to the page each time data is pulled from the database. The other reason involves some "tree gauging" data used by the 117 elements. Comparing 8.0 and 9.0, the memory increases by about 450 MB in 9.0. This is due to the tree gauging data being allocated once at the start of solution instead of during each element formulation pass. In 8.0 and previous versions, this tree gauging data was allocated and deallocated within the element formulation loop which was inefficient in terms of elapsed time. However, it kept the peak memory usage lower by not being in-memory while the Sparse solver memory was allocated. In 8.1 and later versions, the tree guaging data was/is in-memory at the same time as the Sparse solver memory thus increasing the peak memory requirements. Since this problem only does one equation solution, the efficiency of only doing the tree gauging once is not realized. In 10.0, the peak memory is reduced by about 225 MB compared to 9.0 due to some changes to the tree gauging code. |
||
|