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Hallo,

I am working on gas metal arc welding simulation and i am trying to compute the temperature field by using the commerical software LS-DYNA. I am totally new to this software thats why i am facing lot of hurdle in the simulation.

Can anyone here tell e how i can use the LS PrePost Welding GUI and make me heat source move along the weld line?? It will be very helpful, if anyone can send me some detail documents regarding such kind of simulation.

Regards

Braj

Dear All

Have you run into the situation that the steel plate fails (through the thickness of 8mm) in the gripped area in the tensile fatigue test.

The recommended gripping force (pressure *piston area=1.15 of the test loading) checked and used but I still get this when the number of cycles approximate 1 million for the falied specimens. The test loading is far more than the fatigue limit of my material.

I  don't have any hole or defects in the solid flat gripped area. 

Thanks for comments and suggestion in advance

Please help me to solve error in abaqus "Session has been idle for longer than 3600 seconds"

Deal All, 

I am trying to implement a UMAT( UMAT41) in lS dyna for soft tissues modelling. I have sucessfully created the smp .exe file on wndows but required to create the MPP .exe file to run on our high performance computing facility (HPC) at IIT Delhi which is a redhat(linux based) system. 

Hi,

In multiaxial loading and in the presence of plasticity, To calculate the total strain at dislocation/notch from Abaqus can I used the following formula? 

to consider the multiaxial loading effect, use the effective plastic strain instead of the nominal plastic strain PE1, or, PE2,..

Total  strain = elastic strain +plastic strain 

                 = stress(von mises)/Elastic modulus + PEEQ (effective plastic strain)

Dear all,

I'm using abaqus to build a spherical model, which applies C3D8 linear brick element.  I output the connectivities of one element on the surface and the corresponding coordinates. 

For a linear brick element, the four nodes A,B,C and D on the same surface should lie on the same plane.  However, I got two different normals which are from A,B,C as well as A,B,D.

Is it reasonable or do I misunderstand something?

Best

Hi

I am trying to calculate the Ni-number of cycles for crack initiation from noched steel specimens under multiaxial loading.  I start with the finite element to calculate the max stress and max strain at the notch and end with these questions: 

Assuming the isotropic hardening elastic-perfectly plastic model, and monotonic load equal to the maximum fatigue test loading (S-max in the cyclic loading). 

What is the explanation that the maximum stress-strain are not at the notch but a few mm from the notch?

Is there any way to pass the plastic strain components to ABAQUS subroutines, e.g. VUHARD? I'm wondering whether I could write a subroutine to calculate the equivalent plastic strain directly from plastic strain components. 

I'm working on a dynamic simulation using ABAQUS/Explicit. The material is under a high-frequency loading and unloading, and large deformation is expected. 

ABAQUS calculate the equivalent plastic strain in the rate form, which returned me an outrageous PEEQ value. Ironically, all the PE components seem correct.  

I've got a question about anisotropic plastic. The anisotropic models like Hill or Barlat yield criteria are about anisotropic yielding. However, the hardening behaviors in different directions like rolling direction or transverse direction are still the same, i.e. they work harden in the same speed. My question is what if material in different directions work hardens in different speed? How can I deal with this in finite element simulation?

I m trying to extract energy at each integration point in Abaqus. I can do it for stresses or strains but i cant do for the energetical quantities. The obtained error is : “KeyError: 'ELEN'”, but in Abaqus it is the good keyword… Below it is my code to extract it :

from odbAccess import*import numpy as np

odb = openOdb(path='C:/Desktop/Fish1.odb')# lastFrame = odb.steps['Step-2'].frames[-1]
lastFrame = odb.steps['Step-1'].frames[-1]

topCenter = \
odb.rootAssembly.instances['PART-1-1']
stressField = lastFrame.fieldOutputs['ELEN']