244 questions
Tooling
0
votes
2
replies
43
views
OpenSCAD. A way to assign materials
I want to try out structure design. What i've done by far is a SCAD model for four trays and a cover above them.
// PARAMETERS
Length = 2000;
Width = 225;
Height = 38;
Wall = 2;
CoverThickness = 5;
...
- 1,057
0
votes
0
answers
25
views
Is there a way to convert wireframe models to solid, watertight exports for FEA
I've been trying to convert this wireframe into a solid 3d model for finite element analysis and I'm just lost. Here's the code and an image of the wireframe and thank you for your help :) :
...
- 23
0
votes
0
answers
40
views
Time complexity of FEM-simulation of biphasic problem
I am trying to estimate the time complexity of an FEM simulation, that solves the normal contact between a biphasic block and an rigid indenter.
Say the block has a mesh with N x N x M nodes and the ...
- 13
2
votes
1
answer
142
views
Generalized Nonsymmetric Eigensolver Python
How do I solve a nonsymmetric eigenproblem. In terms of scipy.sparse.linalg.eigsh the matrix needs to be "real symmetric square matrix or complex Hermitian matrix A" (https://docs.scipy.org/...
- 23
0
votes
1
answer
151
views
Quad structured mesh with Gmsh using transfinite option starting from an stl file
I'm using GMSH through Python API to create a structured quadrangular mesh to perform FEM analysis of an ascending aorta for my master thesis. I have definied, on the surface of my geometry, ...
0
votes
1
answer
187
views
Gmsh example t4.py unable to find t4_image.png, other examples run fine
Goal is to solve my previous question Generate a mesh from my polygon geometry to iterate FEM for geometry optimization? by myself using Gmsh
I've installed Gmsh (also) 4.12.2 using pip on macOS 10.15....
- 3,835
2
votes
0
answers
475
views
Generate a mesh from my polygon geometry to iterate FEM for geometry optimization?
The 2D script below generates polygons in a box, which represent a cross-section of three cylindrical rings parallel to the z axis which will have voltages applied. I'll solve the Laplace equation in ...
- 3,835
0
votes
1
answer
236
views
Meaning of mesh_size
In the following, does "mesh_size" refer to the maximum perimeter or maximum area of each element?
with pygmsh.geo.Geometry() as geom:
geom.add_polygon(
[
[0.0, 0.0],
...
- 101
0
votes
1
answer
950
views
How to connect a mesh using gmsh and vtk in python
I'm working on a project that creates and manipulates meshes on geometric objects using the finite element method. So far, the user imports a file (.step) and selects areas of the object to create ...
1
vote
1
answer
199
views
Finite Element Analysis with Gridap.jl; how to define Von Mises stresses in Linear Elasticity problem?
From the Gridap.jl tutorial, I am struggling to compute the Von Mises stresses. I would love to get the feedback from the community on how to compute the Von Mises Stresses in the correct way. In this ...
- 589
0
votes
1
answer
49
views
FEM: computing edge values from continuous function (Whitney p-forms)
I'm writing a Finite element method based on Whitney p-forms, where the solution coefficients are defined on edges and faces.
For example, the electric field can be approximated as
vec(E) = sum e_i ...
2
votes
1
answer
80
views
Python gekko line break in equation definition
I'm currently implementing the Galerkin-Method for finite Elements by hand and using python gekko to solve the resulting non-linear algebraic equation system. This creates no issues for small systems ...
- 174
1
vote
1
answer
298
views
Sparse matrix solver in java using ojAlgo library
I'm currently doing FEM calculations in java on very large square matrices with sizes up to 1M x 1M. These are very sparse though with under 10M entries. I'm using ojAlgo with the SparseStore matrix ...
- 55
0
votes
0
answers
111
views
finite element analysis in mathematica
I have been having trouble solving a coupled set of PDEs in mathematica (electrical current flow), and the issue appears to be in the boundary conditions. Specifically, I have PDES as follows:
sum_{i} ...
- 375
1
vote
0
answers
147
views
1D finite element method in the Hermite basis (P3C1) - Problem of solution calculation
I am currently working on solving the problem $-\alpha u'' + \beta u = f$ with Neumann conditions on the edge, with the finite element method in MATLAB.
I managed to set up a code that works for P1 ...
- 43
0
votes
1
answer
3k
views
How to Create Piecewise Function in SymPy with Intervals
i need to create a piece-wise function inside an interval but sympy piecewise can't use and (&). I read that the function can't recieve Boolean values so I tried to add them together and it doesn'...
- 7
0
votes
1
answer
141
views
"Error using vertcat Dimensions of arrays being concatenated are not consistent." in matlab while using integral2
I'm coding a programme about FEM and here is my code
FEM_2D_TRI_QUA_1.m
N1=2;
N2=2;
N=2*N1*N2;
top=1;
bottom=0;
left=0;
right=1;
h1=(right-left)/N1;
h2=(top-bottom)/N2;
T=zeros(3,2*N1*N2);
N10=N1+1;
...
- 11
0
votes
1
answer
444
views
How to setup MATLAB shape function solver
I am trying to find the shape function for a finite element analysis problem in MATLAB. The basic shape function looks like, with the boundary condition on the left. At Ni=N1, x=x1, y=y1 (the ...
- 129
2
votes
0
answers
65
views
Is it possibile to optimize Plotly carpet rendering?
I am working on a plotter for Finite Element Method solutions. I decided to use the Plotly library because of the carpet plots. I have my data to plot and this is my result:
Flow over NACA0012
Each ...
1
vote
1
answer
1k
views
Generate unstructured surface mesh from coordinates
Problem summary
I have a rectangular prism like in the image below where I know the coordinates of the vertices.
I want to discretize the lateral faces of the prism into an unstructured surface mesh ...
- 319
0
votes
0
answers
729
views
How to avoid accumulated error over time and "drift" in numerical time integration?
I'm coding a few programs to study structural dynamics problems, and I'm trying to understand how to estimate and minimize accumulated error over time for large-time scale calculations.
An explicit ...
0
votes
0
answers
259
views
Setting Boundary Conditions in Finite Element
EDIT: See solution in the full code, following @bgb2's comment.
I'm currently trying to code a Finite Element Analysis to solve a 2D heat conduction problem. For now I'm looking at the steady state ...
- 935
0
votes
0
answers
137
views
Is it possible to perform a geometric non-linear analysis in Abaqus with multiple independent steps?
I am trying to analyse a large structure with multiple loading scenarios (independent - different loading directions), while considering geometric non-linearity. Using different steps is not ...
- 3
0
votes
1
answer
388
views
How to use two UEL in same problem in ABAQUS
I am solving a contact problem. A footing under compressive load placed over soil. I would like to use two different types of user-defined elements one for the soil and other for the footing. Please ...
1
vote
1
answer
1k
views
Is three.js able to show FEA results?
I’m trying to develop an real-time wind turbine simulation Finite Element Analysis software using three.js to display the caculated 3D FEA results. Like the image one frame of FEA result.the showed 3D ...
- 33