Computational Mechanics Forum

Hi

I am modelling a contact problem using Abaqus and I am trying to use remeshing hoping to get more accurate results in critical locations. But I encounter following error:" the area of 7 elements is zero, small or negative". Despite of the definitions of the remeshing rules always the error message appears when size of elements  is quite a small. My goal is to get minimum element size 1E-7m in critical location. The error message appears much before that goal. I am very grateful if someone could help.

Hi,

I have developed a FORTRAN code to simulate the molding process of glass to make lenses. Hence, it involves a contact analysis between the glass and molds. The contact is modeled using the master and slave node concept and the mold is assumed to be rigid. For the application of this code, we are looking at highly precise dimensions to capture the curve of the mold on the glass after molding.

Hi,

I am reading the book on-Non linear finite element analysis by M.A.Crisfield-as some of you know(as I've posted questions earlier too),it's more of a self study that I am doing-I have got some fundamental questions in chapter 3-the topic on:

Section 3.3 A Truss element based on Green's strain.

Basically the author has divided into 3 sections wherein we have:

Section 3.3.1 Geometry and stress strain relationships

Section 3.3.2 Equilibrium and internal force vector

Section 3.3.3 The tangent stiffness matrix

Dear All,



Could you suggest any literature or online step by step tutorial on how to create your own subroutines in ABAQUS like umeshmotion or umat. Any relevant information would be much appreciated. I am looking for information that are not covered in the ABAQUS manual.

Thanks very much in advace,



Nicholas

Consider attached file.It lists the details of the Timoshinko method for geometric non linear analysis.

Can anyone tell me how is it diiferent from incremental analysis conceptually?

Is it used commercially?Which method is more sophisticated-Timoshinko,incremental or Newton Raphson?

Please help

I have designed a large boat trailer structure and FEA analyzed it statically.



Now, i want to know if it's possible in CATIA to compute the needed pulling force/power that the trailer will need to start moving. I assume a load of 200ton on the trailer frame and some frictional data must be entered to the wheels/ground contact surface. Anyone has ever done something similar before?

Dear all,

I am writing a program for crystal plasticity using VUMAT. I met some problems, hope you guys can help me out.

Assume each node represents a single crystal. At each step, VUMAT will give strain increment which is based on curent configuration(right?)

Then I can calculate the shear strain in each slip system and obtain the plastic deformation gradient. So I can get the elastic deformation gradient for current step. Using polar decomposition, rigid body rotation matrix can be obtained.

This is an extract from wiekepedia: 

Strain measures

Depending on the amount of strain, i.e. local deformation, the analysis of deformation is subdivided into three deformation theories:

Hi. I'm now starting my PhD on a project on sintering of hard metal.

I'm doing a literature study, but I have failed to find any articles that uses FE analysis on the micro/mesoscale. All of them seems to handle this only with a homogenized model on the macroscale.
If I get to be picky, I would prefer something with hardmetal, but at this point, anything would be great.
I would also be very happy to find any suitable reading on FE-analysis on solid-liquid-pore mixtures.