Skip to main content

Ask iMechanica

Description

If your topic fits none of the following forums, post it in this default forum

ABQ Python Scripting to create mesh definition without geometry

Submitted by jo-heintz on
Forums
Ask iMechanica
Choose a channel featured in the header of iMechanica
research
Free Tags
ABAQUS/CAE
Dear iMecanica community,

with ABQ I'd like to create a mesh part without an associated geometry using the bottom-up-technique.
I already found the Python commands to add nodes to an orphaned mesh (from an inp-file).
In order to this I must first import an existing part and make node definitions on the orphan mesh part.
Is there a way in ABQ to define nodes, elements, etc. directly using scripting commands without
creating an orphan mesh part (by importing a model)?

Question in deformations, continuum mechanics

Submitted by AP on
Forums
Ask iMechanica





Hello,

I have a question in intoductory continuum mechanics, in strains and deformations.

 Source of image: wikipedia, http://en.wikipedia.org/wiki/Deformation_(mechanics)

 

In above  image, point B in reference configuration becomes b in current configuration. Vertical displacement of b is given by uy + (duy/dx)*dx.

Please suggest good books for nonlinear FEM and mechanics of composite materials

Submitted by AP on
Forums
Ask iMechanica
Free Tags
nonlinear finite element formulations
composite material

Hello,

For my project I need to learn nonlinear finite element method (FEM) and composite materials. I am familier with linear FEM. Please suggest me good book for nonlinear FEM which will have good explanation of the subject. Also, please suggest book on composite materials especially having lot of solved examples. I know there are lots of experts in this subject on imechanica, so please give me some suggestions. Thanks. 

Thanks.  

Reading off data from output database file when UMAT is applied

Submitted by icin on
Forums
Ask iMechanica
Choose a channel featured in the header of iMechanica
research
Hi ~!
i tried to analyze stress-strain distribution when material is subject to self shrinkage due to drying.
first, i performed water diffusion analysis. second, i performed static analysis with predefined fields data 
from .odb file of the previous analysis results. and it was successful. 

but when i try to use subroutine 'UMAT', .odb file of the previous analysis becomes not availalbe to be read off.
the only thing changed to use 'UMAT' in input file is described below.

Residual stresses 2D to 3D

Submitted by HoneyVerma on
Forums
Ask iMechanica
Choose a channel featured in the header of iMechanica
education

Hello,

i have simulated welding in 2D model for beam attached with cover plates at both the flanges using Abaqus, now i want to use the same residual stress distribution for whole 3D cover plated beam with same cross-section,so that i can find load carring capacity of beam.

but i am not sure, is it possible to find stresses in 2D model then use the same residual stress in 3D model? i try using initial state and restart option but it is not reading the same stresses for whole lenght.so is there any other way of doing this??

Mismatch between built-in linear-elastic material behaviour and tutorial VUMAT in ABQ/Explicit using truss elements

Submitted by jo-heintz on
Forums
Ask iMechanica
Choose a channel featured in the header of iMechanica
education

Hello dear all,



for my master's thesis I'd like to write a simple VUMAT for a material with nearly zero compression stiffness.



So for a better understanding of VUMAT subroutines I did the ABQ tutorial for a VUMAT with isotropic, isothermal elastic material behaviour and compared the results with the built-in material definition.



There is a discrepancy of almost 35% of the S11 stress. ABQ Manual says that both times the Green-Naghdi stress-rate formulation is used.



Non-uniform expansion coefficient alpha in UEXPAN (ABAQUS)

Submitted by youmotou on
Forums
Ask iMechanica
Choose a channel featured in the header of iMechanica
software
Free Tags
User subroutines in ABAQUS

I want to define the expansion coefficient alpha as a function of the depth, alpha(z)=f(z). How can I achieve this in UEXPAN? I cannot find a way to incorporate coordinates in UEXPAN.

Subscribe to Ask iMechanica