MartinaC

Hi everyone, is it possible to define as input data the behaviour curve of a non linear elasto-plastic matierial in a MAT1 card image material with the NL parameters activated? I tried to import the curve, changing the TYPSTRN value, but the solver Optistruct does not start. The curve has non linear trend both in the elastic that in the plastic phase. Bests Martina

There are other possibilities to simulate tensile tests of non homogeneous coupon bars and export the global stress-strain curve? Because I am able to export just the stress-strain curve of each element Best Martina

Hi everyone, I am simulating a tensile test with Optistruct. The analysis is NLQS and the material is isotropic. I set the analysis as proposed in the eBook "Introduction of Non linear finite element analysis using Optistruct", section 3.1.5 Tutorial: Small-Strain and Large-Strain Plasticity in a Test Coupon. I would like to understand how to set the CELAS1 element in order to use it for the building of the force-displacement output curve. I created the element, but the output curve results flat, so I think the problem is the Set. Attached is the .fem file, is usefull. Bests Martina MODEL2_surfs_JarvO1_NLQS.fem

Thank you very much Rahul.

Thank you. Yes, I have to perform SED analysis.

Here the files, if you can find a different solution for my problem. The .h3d is too heavy to be uploaded here. MODEL2_surfs_O1_fy200_NLQS.fem MODEL2_surfs_O1_fy200_NLQS.out

Thank you very much. I modified the stress-strain input curve and it worked!

Of course. I attach elso the TABLES1. I imposed the strains between 0 and 1 because shown in the eBook. The real material has maximum total strain equal to 0.3.

Hi everyone, I am simulating tensile tests with welded samples. I am using NLQS analysis in Optistruct, according to the eBook Introduction to Non Linear Finite Element Analysis using Optistruct. My problem is that the stress-displacement curve after the simulation shows stresses which value is higher than the ultimate stress imposed with the TABLES1. How is it possible? Why the stress-displacement curve does not become flat? Does it have any meaning? Bests Martina

Hi everyone! Is there the possibility to mesh a surface with elements like in the attached image? Bests Martina

Hi everyone, I am modeling a 3D hollow element made by more components in Hypermesh to conduct NLQS analysis with Optistruct. My system is symmetric and I want to know if there is the possibility to tell the software that the unmodeled part is the mirror of the modeled part, so that it considers the constraints due to the symmetry. I know the software allows to reflects elements, but I would like to not works with too many nodes. I attach pictures: 1 is the modeled/discretized part; 2 is the entire system (modeled, unmodeled parts) Thanks Martina

Of course. Now I tried to add some other support to the element: the analysis is running. I will see if it converges when it will end. Simm2D_full compression_NLQS.out

With my professor we thought the model was numerically too complex to be analyzed. So we simplified the model with a scheme and analyzed its behavior. Thanks for your support Martina

Hi everyone, I am performing a non-linear quasi-static analysis on a system made by elements with different materials and geometry. I attach the files. The system has an SPC for dof 1, 2, 3 at the bottom part and compression pressure on the other 3 sides. The problem is that the analysis does not converge because of error 4965. Is this a problem of the load pattern or load type, or a problem of analysis parameter setting? Before this trial I performed on the same model a non-linear quasi-static analysis of simple tension along x axis imposing a displacement on the right side of the system and an SPC for dof 1, 2, 3 on the left side and the analysis converged. After this I imposed the displacement also along y axis, but it didn't converge, so I tried with forces, and then pressures, but the analysis didn't converge. If the problem is the load setting, the definition of an envelope of the vertical loads with the horizontal loads could give good results? Bests Martina Simm2D_full_compression.hm

Thank you Rahul!