Copper material modelling using Johnson Cook model in LS DYNA
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Plane stress Abaqus UMAT
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Hello everyone,
I have created a UMAT code for J2 elasto-plasticity with isotropic hardening for 3D solid elements.
At this point I would like to support also plane stress shell elements. What changes in the code are
suggested? The already implemented code, takes as input the strain tensor at time tn and the strain
increment tensor and updates the stress at time tn+1 and calculates the material Jacobian and
achieve quadratic convergence. The stress and strain tensors are manipulated as 6x1 vectors and the
How to import edited node coordinates (mesh) to Abaqus?
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import modified nodes coordinates to abaqus
Abaqus nodes are missing degree of freedoms. ErrNodeMissingDofConstrDef
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Problem Description/Question:
I model a cantilever beam with 2D plane stress elements.
The left end of the beam is clampled (encastre).
In Step 1, I use a coupling constraint U2=coupled to apply a vertical load on the right (loaded) end of the model.
In Step 2, I use a different coupling constraint U1=coupled to apply a traction load on the loaded end of the model.
Each constrain is defined with different reference point, different surface, totally independent of each other.
Ackward behavior in Abaqus
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Hello colleagues!
I am facing a very strange phenomenon in Abaqus 2019. Setting up a transient consolidation analysis, and despite converging and showing job as complete, no output is written to the job at all. Needless to say, I am requesting standard field output every n=1 steps and the analysis is 10 increments or so. It's quite frustrating to see your mesh disappear when you expect to see nice colors. If this ever happened to you please do share how you went about it.
Cheers,
When to use equation of state models for modeling hydrodynamic response in metals?
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Equation of state models (Mie-Gruneisen equation of state etc) have been widely used to study hydrodynamic response of material during explosive deformation, ballistic impacts for a long time. As far as I understand, a hydrodynamic response is required to be incorporated in a model if the pressure of impact leads to an increase volumetric strength. That is the stress wave speed in the material exceeds the speed of sound in the material (v = sqrt(elastic modulus/density)). Ballistic impacts occur at strain rates close to 10^9 to 10^12/s.
What causes the other: Stress cause strain or Strain cause stress ( Conjugated Polymers)
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I am struggling in understanding a theorem related to a conjugated polymer which is based on the electro-chemo-mechanical working principle.
The basic idea of the actuator is constructed from three layers, the up and bottom are conductive and the medium layer is dielectric and when the voltage applied the ions migrates to fill the holes.
It is mentioned that the expansion is happening because of the migration of the ions and then the stress occurs.
I don't agree with it as what makes the ions migrate is the electrostatic force and then the strain occurs.
How to automate surface creation in Abaqus ?
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I would like to create a surface (on top side of a cube) in Abaqus
I am aware of doing it manually by using the following in GUI :
1) Tools->Surface-> Create
2) Select regions for surface by the angle
This is what I tried and failed :
1. Obtained all the nodes belonging to a face
2. Obtained all the elements connected to the nodes of step 1
3. Created an surface using the elements obtained in step 2 by appending the following lines in the .inp file
how to access the main page of abaqus-docs.mit.edu
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I found a great tutorial for abaqus/cae at https://abaqus-docs.mit.edu/2017/English/SIMACAEGSARefMap/simagsa-m-Caeb... but I cannot find the main page, which I need to navigate it; I am forced to Google for individual sections guessing at what the section titles migh be; I need a URL to the root page so I can navigate the tutorial like an ebook.
Abaqus startup start-up initialization file Python script
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I need to find a startup file that Abaqus/CAE reads on startup to add a line of Python to modify the behavior the way I like it. I find myself adding this line manually every time I start Abaqus/CAE and I am tired of it. Like the .gpr file but .grp is a binary file--I cannot add things to it with a text editor. It has to be an initialization file, right? Or may be some other way to do it. Thanks in advance.