# Questions tagged [acegen]

AceGen is a Mathematica package for automatic code generation, focused on finite element method subroutines.

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91 views

### Negative Jacobian for small finite element in AceFEM

I want to make simulation for 1 hexahedral finite element of dimensions 1mm x 1mm x 1mm. I need to use SI units (metres) as below in the code ...
• 65
63 views

### SMTShowMesh with additional graphics in SMTRestart session

Some time ago I posted a question concerning additional graphics for SMTShowMesh[] SMTShowMesh with additional graphics Now I want to include additional graphics in SMTRestart[] session for ...
• 65
156 views

### AceFEM-generated mesh versus Mathematica mesh: How to extrude 2D mesh to create a 3D mesh in AceFEM

The packages MeshTools (@Pinti) and FEMAddons seem to feature similar functions. I sometimes had strange (i.e. inconsistent results when meshing would work/not work without changing anything). Which ...
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1 vote
109 views

### How to enforce DOFs to have the same values in AceFEM?

I want to make simulation of shearing of one cubic finite element as in the code below. How can I constrain all horizontal displacements (in X direction) of nodes "X"==L to have the same ...
• 65
86 views

### AceGen: Assemble a user specific global array (similar to "Residual")

I have an issue which I know is definitely solvable but I don't know how to implement this in AceGen. Basically, I want to assemble a matrix $\mathbf{L} \in \mathbb{R}^{n_{dof} \times 6}$ for a global ...
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1 vote
79 views

### SMSDo Error when try to use counter variable i as vector index in loop

I try to evaluate the following code, but I get "Error during numerical evaluation of expression with random numbers." Expression contains parts that canot be evaluated. Messages: ...
138 views

### Why are my AceGen results not matching with the commercial FE software?

I conducted a linear FE analysis of a 3D cantilever beam using AceGen/Acefem and Ansys. I find that results are a little bit off from the ansys results. For e.g., the deflection reported at the ...
• 101
92 views

### Question regarding initial guesses for Newton's method in AceGen/ AceFEM

I am trying to solve a system of equations with the command SMTNewtonIteration[]. This method needs initial guesses for the degrees of freedom I am looking for. Is ...
90 views

### Split module "Tangent and Residual" to two modules "Tangent" and "Residual"

I am struggling with an issue and need advice. In general: My objective is to implement a Quasi-Newton (QN) method using a small strain elasto-plastic element from the main library and a user defined ...
• 45
76 views

### Meaning of divergence message?

I am using the command SMTNewtonIteration[] to solve a boundary value problem in AceFEM and get the following error message: What does this message mean exactly? ...
64 views

### AceGen/AceFEM: Divergence in a term, that should be equal to zero

I have a problem concerning the order of the evaluation of the AceFEM parameters. My AceGen Element contains, among many others, an expression of the form B (aa - bb/(cc Exp[dd w^2] + ff)) with B, aa, ...
1 vote
98 views

### Integrate doesn't give a result for non-linear functions

I use Acegen for Finitie Element formulation that gives out residuals and tangents by taking in the field values as inputs. For this in my residual formulation I need to integrate a nonlinear term ...
• 13
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### How to extract gauss coordinates in AceGen/ AceFEM?

I am trying to implement a 2D turbulence problem with the model of Spalart-Allmaras. Therefore, I need to extract the global gauss coordinates to define parameter 'd' which stands for the distance to ...
85 views

### AceGen/ AceFEM: Wrong number of nodes?

I am trying to create an element T1 (linear triangle) to solve the steady, incompressible Navier-Stokes equations. Therefore, my SMSTemplate command reads as follows ...
1 vote
83 views

### Numbering of auxiliary symbols in AceGen generated code

I have a general question regarding the numbering of auxiliary symbols in AceGen. Consider this example (taken from the AceGen manual, only the language is switched to ...
147 views

### AceFEM higher order elements fail basic test

I was trying to perform a simple test, as some results that we obtained from AceFEM were not matching with the results we obtained from other methods. Here, I have a simple biaxial test on a cube of ...
• 33
146 views

### How to modify global stiffness matrix before solving it by SMTNewtonIteration[]?

I'm trying to use the Model Order Reduction technique to reduce the stiffness matrix in AceFEM/AceGen. But there is a problem with the manipulation of the global stiffness before solving it by ...
106 views

### Dynamic allocation of memory within the given array

Let say a have an array of known dimension array={-1, 3, 6, -5, -6, 12} and indexes where the negative numbers appear is not known in advance. I want to create an array for which elements satisfy ...
• 33
174 views

### Is it possible to remove an element during computation in AceFEM?

The title says it all. I know there have been a lot of enhancements in the recent versions of AceGen/AceFEM. I would like to know if there is a possibility of removing an element during computation (...
• 1,309
1 vote
97 views

### Different boundary conditions

I have a problem regarding the definition of multiple boundary conditions in AceFEM. I am dealing with coupled problem simulations (displacement and magnetic potential) and therefore I have to apply ...
• 634
1 vote
127 views

### Strange visualization for H2S element

I am experiencing a strange behavior in the postprocessing of H2S element. I have provided a MWE below. Reference: H2 element ...
• 1,309
109 views

### Package AceFEM error: cannot be automatically installed

I have a problem to perform the package AceFEM in Mathematica 12.0.0.0 for Mac (software: macOS Monterey Version 12.4 | processor: 1,8 GHz Dual-Core Intel Core i5). I downloaded the newest AceGen and ...
121 views

### How to stop simulation after a given model variable achieves certain value?

I would like to stop my simulation after a given model variable (say, plastic strain averaged over entire domain) achieves a given threshold value. Do you know how to do it? I'm supplying the MWE. How ...
1 vote
35 views

### Number of input parameters (nargin equivalent) for AceGen

Is there an equivalent to the MATLAB parameter nargin that can be used in AceGen? For example, consider a function that takes in two vectors and an optional scalar. ...
82 views

### Clear AceFEM memory

I am doing multiple AceFEM simulations by invoking the mathematica notebooks using NotebookEvaluate. After a number of simulations everything breaks down, I suppose the problem is too much memory ...
139 views

### Calculate ArcTan in AceGen

I am working on a material model SMSStandardModule["Tangent and residual"] in AceGen and want to use command ToSphericalCoordinates for but AceGen is ...
342 views

### AceGen/ AceFem on new M1 Mac

Apple has updated its processors some time ago and I am curious if AceGen/ AceFem are compatible with this latest generation of the Apple M1 processors? And maybe someone can already report on the ...
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1 vote
230 views

I wonder whether there is any way to add data directly to the linear equation system in AceFEM. I´m having external data that I want to superimpose to the linear system before solving it. The targeted ...
95 views

### AceFEM: MIEL example aborts for many load steps

I am currently using AceFEM version 7.303 and Mathematica 12.2 but had the same problem with other versions before. My laptop as well as the server I use work with Linux. When I run the example "...
• 43
234 views

### 3D meshing of cyllindrical domain into hexahedral elements

I need a solution for generating a hexahedral mesh for a cyllindrical domain in Mathematica/AceFEM. Ideally, it should be close to cyllindrical symmetry not very far from the center. The best option ...
132 views

### AceGen SMSFreeze[] function

I'm quite new to AceGen and I'm not getting the function of SMSFreeze[]. The manual writes the following: SMSFreeze[symbol,{exp1 ,exp2 ,{exp3…}..},allOptions] create data objects that represent ...
128 views

### AceGen: Keep full symmetric matrix

I am using AceGen to compile a subroutine for MATLAB. The subroutine involves several steps of linear algebra that yields a number of symmetric matrices. However, when using AceGen there seems to be ...
234 views

### AceFEM: Divergence in iterative procedure (Newton-Raphson) for fine meshes

I am trying to model a problem of a nearly incompressible $10~\rm{m} \times 2~\rm{m}$ beam with a uniformly distributed end load. The beam has a Young's modulus of $200~\rm{Pa}$ and a Poisson's ratio ...
163 views

### AceFem Error in SMTShowMesh

I consider for a calculation a sphere embedded within a matrix. To plot the results and especially the behavior around the spherical inclusion I want to "cut" through the matrix. That seems ...
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164 views

### Running AceGen / AceFEM on a cluster

Did anyone here ever sucessfully installed AceGen/AceFEM on a cluster? Does anyone has experience with performing AceFEM simulations on a cluster system? Is it possible at all?
181 views

### Parallel/Multi-thread element code generation using AceGen

I am using AceGen to generate source code for finite element simulations in AceFEM. I have elements with a very large number of vertices/degrees of freedom which can take a very long time to compile. ...
1 vote
286 views

### Print global stiffness matrix in AceFEM

I have a 2D linear elastic simulation in AceFEM and for post-processing purposes I would like to print the global stiffness matrix and global displacement vector. I am able to get the global x and y ...
140 views

### initial condition in finite element method

I want to apply the initial condition below to the linear element c(x; 0) = sin(10πx); if x in [0; 0:1] and c(x; 0) = 0; if x in [0:1; 1]. I tried like ...
201 views

### Meshing an inclusion in an inclusion

I do have FEM mesh related question. I am trying to mesh some inclusion from a png file using ToElementMesh. Thats working quite nicely even for more complex structures. ...
• 634
140 views

### Help with script for running AceGen generated routine in ABAQUS

I am using the below configuration to run a AceGen-generated viscoelastic element in Abaqus. Abaqus version: ABAQUS 6.14-6, OS: Windows 10, Visual studio: 2013, Fortan compiler: Intel Fortran compiler ...
1 vote
36 views

### AceGen set up for Linux [closed]

I would like to run Abaqus User Element (UEL) subroutine generated by AceGen. I have Abaqus 6.14 coupled with gfortran compiler in Linux Ubuntu operating system. How do I configure ABAQUSCompile.bat ,...
131 views

### Coupling AceGen with Abaqus

I am using Abaqus for nonlinear FEA and, I have generated a UEL (User defined Element Subroutine)using AceGen. But the .log file generated by Abaqus shows a syntax error when I try to run a job using ...
619 views

### 3D Inclusion with structured mesh and coarse and arbitrary matrix

I am wondering if there is a simple way to define a structured 3D mesh (inclusion) like e.g. that and surround it with a corse and unstructured Matrix. It should be possible to refine both more or ...
• 634
1k views

### General:: Exp[-717.401] is too small to represent as a normalized machine number; precision may be lost

I am solving pde. For the post processing bvp, there is solution given in output which is the solution from mathematica version 10.0.1. Output from above in mathematica 10.0.1 is, But when the similar ...
104 views

### How to obtain eigenvectors in AceGen

I'm trying to obtain eigenvectors of a 3D plastic stretch tensor $C_p$. There is no SMSEigenvectors function, so I tried with ...
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49 views

### AceFEM MacOS not responding

I just upgraded to v7.114 of AceFEM running on MacOS 10.15.5 and Mathematica 12.0.0.0. I was running v7.101 without a problem. AceGEN seems to work but all AceFEM code starts but does nothing. The ...
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254 views

I tried to run AceGen/AceFEM on my Mac(10.15.5). I installed Mathematica (12.1.0.0) successfully and also the latest version of the AcePackage (7.113). The installation of the AcePackage is successful,...
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316 views

### Deformation following loads in AceFEM/AceGen

I have a simple 2D finite element problem comprising a unit domain that is fully constrained on the left, vertically constrained on the bottom and subject to a uniformly distributed load at the top. ...