FEM

Deformation gradient change in Abaqus

Submitted by ratgem.shetty on Tue, 06/03/2014 - 14:29

Help needed!! in Abaqus

I have UMAT written to update stress and material tangent components for a user defined material model. I need stretch ratio as an input for my material model. For this I am using deformation gradient from UMAT. Problem is, when there is constant strain (strain rate = 0), for example when material stretched to 100% strain (rubber) and then held at that strain for certain time to see stress relaxation, the deformation gradient should give the same value of 100% strain, but to my surprise this is changing. Can any one help me with this.

What are the regular iteration steps of cohesive model based FEM for crack problems

Submitted by Wen Ye on Sun, 05/04/2014 - 12:25

Hi,

I'm now start to learn cohesive zone model based FEM for crack problems. According the a regular coehsize model (bilinear for example), the relative displacement and the cohesive stress are both unknwon, so iteration is required. My question is that what are the regular iteration steps?

Thanks.

Modeling of Particulate Composites

Submitted by Yogesh_Bisht on Tue, 04/29/2014 - 16:50

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I am trying to model particulate composites and simulate their stress-strain response. The problem that I am facing is that the inclusions (stiffer than the matrix) are only acting as points of stress concentration. Consequently their is no strengthening and hence no apparent increase in load carrying capacity of the composite. Any help/suggestioin in this regard would be higly appreciated.

Regards

Abaqus: Composite delamination with cohesive elements

Submitted by Maria Pia on Fri, 04/11/2014 - 11:11

ABAQUS

FEM

composite delamination

Hello,

I have to do a FEA regarding impact damage and delamination propagation in a CFRP specimen.

I have to do this using cohesive element in order to see the propagation of the delamination front in the material.

My problem is that I don't know how to do this in Abaqus.

I'll better explain: I can use this software but is the first time approching composite behavior and I really don't know how to model that.

Mesh free coupled with FEM

Submitted by farzad64 on Thu, 04/10/2014 - 08:01

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Hi All

I would like to know , If part of our model has geometrical complexity , is it reasonable to use meshfree method for that area ? does it fasten or ease the analysis ? how to couple it with FEM ?

PhD position in Analysis of Fracture in Porous Ceramic Catalysts by use of X-ray Tomography

Submitted by hlfrandsen on Wed, 04/09/2014 - 09:11

The Department of Energy Conversion and Storage at the Technical University of Denmark (DTU) and Haldor Topsøe A/S (HTAS) is seeking a candidate for a PhD position in analysis of fracture in porous ceramic steam-reforming catalysts by use of X-ray tomography.

Responsibilities and tasks 

huge difference of Young's modulus in sandwich structure

Submitted by Han Shiwei on Tue, 03/18/2014 - 03:26

research

FEM

sandwich strcuture

I am modeling a plate under three point bending with Abaqus. The plate
is a sandwich structure with aluminum plate (thickness: 5mm), adhesive glue (thickness:
0.02mm) and a kind of foam (thickness: 15mm) bonding together. Their Young’s
modulus is at the order of 100GPa, 1MPa and 100MPa. While in incremental
calculation, the job is always be aborted for not achieving convergence. I just
wonder whether the cause of not achieving convergence should be attributed to
the huge difference in Young’s modulus.

huge difference of Young's modulus in sandwich structure

Submitted by Han Shiwei on Tue, 03/18/2014 - 03:24

FEM

sandwich structure

800x600

Hello,

Method for Simulation of Universal Joint

Submitted by Prahel on Fri, 01/24/2014 - 09:46

FEM

splines

universal joint

Hello Everyone,

I have to simulate and find the pressure on the splines in the universal joint. I have to define contact surface and to find a simple method to run analysis on this joint. I am finding it very difficult to select all the surface on every spline. Also, it will make the simulation very big.

Could anyone please help me to find a method or an easy way out. Any kind of suggestions are most welcome.

Regards

Prahel