I am using exponent Drucker-Prager model at the moment, is there anyone can tell me where the follow exponent D-P eqation comes from originally?
(σ e)(σ e)=λ(σt)(σt)-3(λ-1)σmσt
Where λ= is hydrostatic stress sensitivity parameter and equal to σc/σt, σe is effective stress, σm is hydrostatic stress, σc, σt are stresses under compression and tension, respectively.
I am doing my master thesis on crash simulation of plywood (7 layers-orthotropic material) structures in buses using explicit LS-DYNA FE program. I would like to include failure in my model. Right now I am working on Mat_054_55 (MAT_ENHANCED_COMPOSITE_DAMAGE…..material model from LS-DYNA material library).
Mat_054_55 allows me to get failure by defining anyone of the following parameters,
In a recent rapid communication (see attached paper), using principles of pattern formation, we expose some simple stategies to reliably produce perfect long range order in self-assembling systems. Most self-assembling systems exhibit short ranged order. This imperfection is detrimental to several practical applications. It is almost always possible to produce perfect patterns in small domain sizes but self-assembly over a larger areal span results in defects.
I'm trying to model a composite structure with shell 99 element in Ansys.
I set the thickness and material no. in real constant and prepare an orthotropic material property for that. While ploting the result, as I expect to get the stresses among layers different from other points, but the result is a kind of uniform isotropic graph.
I don't know if any setting other than real constant and material property should be done to get a true result or not. and if I'm true then how can I read the true result.
I will appreciate any help.
I would like to know the difference between Effective Strain, Effective Plastic Strain and Effective Failure Strain.
I want to simulate mold filling of a bar mold with a semisolid alloy by means of FLOW3D cfd package. but there are some problem. for example when I input a file I encounter an error like "level 1 error in subroutine rdstl: level 1 error in subroutine rdstl"in preprocessor. what can I do? does my .stl file have any faults?
other problem with another project is that when i want to solve the problem I encounter an error like "convective flux exceeded stability limit".repeatedly. is my meshing insufficient? how can I solve that too?
Hi,
Thanks for the earlier feedback. I was able execute the user subroutine (UMAT) along with *.inp file only to land into new type of error message:
fatal error lnk1112: module machine type 'IA64' conflicts with target machine type 'X86'
Can somebody please help me to understand what this error means and how to overcome this monster.
I have already installed intel fortran compiler, and microsoft visual studio for windows.
As always thanks for the much needed help.
This issue of the journal club addresses a topic deemed classical by most mechanicians: the onset and evolution of fracture in brittle solids. In the last ten years or so a community of mathematicians have been analyzing the formulation of fracture mechanics models. Although still at a very early stage, there is already a substantial body of work, which either sets in a very rigorous settings some known results, or give rise to other perhaps more surprising ones.
