iterative vs sparse solution SOL 101

[prakhar5aug]

Hi,
what is the actual difference between them.....
iterative solver solved while the sparse solution gave the UFM 9137 and told either to constrain or use bailout......
and whats is SPC where to specify ??

Thanks & Regards,
Prakhar Gupta

 

[BlasMolero]

Dear Prakhar,
Both Iterative & Direct solvers should give the same error if the model is not properly constrained, then this is not a difference between solvers. With NX NASTRAN v9.1 we have two solvers: DIRECT SPARSE solver and ITERATIVE PCG solver. The direct sparse solver is my prefered solver, is perfect to solve shell & beam models, but if you run very large problems with bulky 3-D solid CTETRA elements, the amount of storage required by a direct solution solver may be too large for the available computer resources. For such problems, the use of the iterative method of solution is necessary.

Best regards,
Blas.

~~~~~~~~~~~~~~~~~~~~~~
Blas Molero Hidalgo
Ingeniero Industrial
Director

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