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Hello,

I made UMAT for some constitutive model.

The everything, in the UMAT code, including constitutive equations and consistent tangent operators are correct.

The problem is that UMAT works at some simple 2D/3D FE model, but sometimes not working in some 3D complex FE model.

The analysis ends due to error 'TOO MANY ATTEMPTS MADE FOR THIS INCREMENT' in msg file.

In data file, only one warning comes out.

"The aspect ratio for 1603 elements exceeds 100 to 1. The elements have been identified in the element set WarnElemAspectRatio."

Hi 

I have few questions:

1- why most the experimental fatigue studies on metal or metal-composites in the literature were adopted a frequency less than 35Hz (the majority of these test have conducted using 20Hz).

I ran into some articles mentioned that the frequency (0-100Hz) has a marginal effect on the fatigue life of metal. is that the only answer

Hello,

I have recently done a simple hourglass model to check the influence of hardening parameters in Abaqus. The reason was the effects of the parameters' change in bigger models were a bit surprising, therefore I needed to investigate the reason using some simpler model. Please see file 1.

After performing tension/compression cycles I got results as shown in files 2, 3, 4 and 5. Please note that only the hardening parameter in the description changes, the other three stays the same for each series.

I am simulating the flow from these (3 inlets) 8 attached figure untill the top of the plate where my outlet is located. 


I am using the following BC 


Inlet - Pressure Inlet 
Outlet - Mass flow outlet 

I am working on inlet pressures between 6- 24 bars . Do i need to use K epsilon or k omega turbulence models currently i am running my simulations in laminar model 

Due to high pressure of 6-24 bar as enough turbulence is generated do i need to select a turbulence model 

I want to create a simulation in Abaqus to get natural frequencies of sloshing tank, should Iperform modal analysis for fluid only or for tank coupled with fluid in it? and how to get natural sloshing frequencies

Hi all,

I'm using ABAQUS-2016 to run a parallel simulation, and I met a problem for assigning periodic BC in large mesh size. I want to make four nodes to be periodic with each other. Normally, I give the node pair in the equation option as:
*Equation
2
nset_1, 2, 1.
nset_2, 2, -1.
*Equation
2
nset_1, 2, 1.
nset_3, 2, -1.
*Equation
2
nset_2, 2, 1.
nset_4, 2, -1.

Hi

This question had been asked here before but with no answer, unfortunately..so I copied it exactly as I run into exactly the same. Your comment appreciated

Here it is

Dear all,

I would like to represent a perfect bond between two steel solids by means of an adhesive composite compound, treated as a solid layer (as first attempt). I defined in Abaqus CAE two tie constraits : 

Hi,

I want to import a cyclic stress strain curve into my model (Uploaded picture). Modelling of non-linearisotropic/kinematic materialbehavior by means of constitutive material description according to Lemaitre-Chaboche.

I only have the stress strain data of cyclic tests. The options are "Hardening: combined" and "data type: stabilized". My Problem is that the strain data has to be increasing in Abaqus. But the cyclic tests include negative strains. How do I avoid this problem?