Questions tagged [finite-element-method]
The finite-element-method tag has no usage guidance.
298
questions
0
votes
0
answers
18
views
How can I determine the best thicknesses of a circular plate to achieve minimum weight and high strength?
I want to design a circular plate made from iron ductile material, So I want to determine the best thicknesses of the profile (t1,t2,t3,...etc) as shown in the image tyo achieve the best plate weight ...
0
votes
2
answers
22
views
What is the difference between maximum principal strain and maximum in-plane principal strain?
For the purpose of answering/explaining this, it does not need to be restricted to strains (i.e., it can be stresses too). I am mainly trying to understand when to use which one (i.e., if I am ...
- 8,134
0
votes
0
answers
30
views
FEA meshing of irregular geometry
I work on the simulation of sand particles and usually use tetrahedral free-meshing to represent their complex geometries for finite element analysis. I have recently spent some time looking into ...
- 9,642
5
votes
1
answer
128
views
PATRAN Order of Operations
To preface this question, almost all of my FEA experience has come from SolidWorks, so I haven't had to deal with these types of problems.
I'm designing a truss structure in PATRAN composed of 1D ...
CommunityBot
- 1
0
votes
1
answer
26
views
Deformation Due to Material Removal and Residual Stress
Suppose I have a piece of metal (of arbitrary geometry) with some residual stress profile. I then remove a chunk of the metal and the piece of metal deforms (due to the residual stress). For ...
- 1,077
0
votes
2
answers
303
views
What is the difference between Frictional non-linearity and Geometric non-linearity in FEA? (In terms of Stiffness matrix)
For geometric non-linearity, we know that as the geometry changes during the analysis, the global stiffness matrix changes since it already is a function of geometry of the structure.
What I want to ...
CommunityBot
- 1
0
votes
0
answers
18
views
Checking if a Residual Stress Field Achieves Mechanical Equilibrium
Suppose I told you the Cauchy Stress Tensor at every point inside a chunk of metal. And, yes, I know this means that I would need to tell you about an infinite number of points - let's ignore that ...
- 15
1
vote
1
answer
24
views
What is the meaning of the traction continuity condition in the generalized momentum balance (continuum mechanics)?
In Nonlinear Finite Elements for Continua and Structures by Belytschko and al. it is stated:
As we have already noted, the strong form, or generalized momentum balance, consists of the momentum ...
CommunityBot
- 1
1
vote
1
answer
67
views
Why do Eigenmodes of a rigid system also diagonalize the Mass and the stiffness matrix seperately?
To set up my question, I will briefly recap the derivation that is usually given for eigenmodes of a system:
If there is no force present, and a body is described by a vector $u$, then the equations ...
CommunityBot
- 1
0
votes
1
answer
23
views
Beam deflection for FEA model validation
I'm trying to validate an FE model that I'm using by comparing to a simplified analytical solution to the problem.
The part I'm analyzing is a lug that is constrained on one end and has a point load ...
- 553
1
vote
1
answer
901
views
Meshing Complex models in abaqus
I'm trying to mesh a model of a morphing wing in Abaqus and have been running into issues. It was recommended that I partition the model into smaller parts, but it seems that the more I try to ...
CommunityBot
- 1
0
votes
1
answer
61
views
Curve-linear vs. Cartesian coordinate systems: linear-elastic & isotropic elasticity tensor
For shell elements, is the elasticity tensor for linear-elastic & isotropic materials the same in a local curve-linear (convected) system vs. a local Cartesian system?
I wonder because ...
CommunityBot
- 1
0
votes
0
answers
24
views
Creating a state-space representation (.m format, Matlab) via Simcenter 3D (NASTRAN) using Component Mode Synthesis Reduction
I'm trying to create a state-space representation of my FE-model using a "Component Mode Synthesis Reduction" (general form of Craig-Brampton reduction). The picture underneath shows (...
- 9,642
1
vote
1
answer
3k
views
Calculate the Euler buckling load of a column using the finite element method
I am trying to find the buckling load of following column:
I started from the system of equations $P = (K + K_g(N))U$, where $K$ is the stiffness matrix of a single 2D frame element and $K_g$ is the ...
CommunityBot
- 1
0
votes
1
answer
223
views
In FEM, what is the difference between a single element with a quadratic shape function and two elements with linear shape functions?
Using Finite Element Analysis to obtain a Weak form of a PDE, what is the difference between the two cases:
A single element with a quadratic shape function
Two elements with linear shape functions.
...
CommunityBot
- 1
0
votes
1
answer
58
views
Determining the critical load of a fixed beam with non-uniform cross-section?
I am a computer scientist, not a mechanical engineer, so it is absolutely possible that I am missing some basic understanding here.
I have a beam that is fixed in both ends and my goal is to ...
CommunityBot
- 1
0
votes
0
answers
11
views
Specific Heat, Pore Fluid In ABAQUS
I want to model a problem that the theory behind is in the "Coupled Pore Fluid Flow and Stress Analysis" context that there is in the ABAQUS online documentation, version 2022. The link to ...
- 9,642
0
votes
0
answers
30
views
New to AutoCAD, trying to accomplish a simple task of trying to simulate how much force can a U channel withstand
Sorry if my question or parts of it seem vague or stupid, I'm fairly new to mechanical engineering. I'm part of a team that is building a simulator platform and I am mostly at the helm of the software ...
1
vote
2
answers
66
views
Finite Element Method for Spherical Objects
I am familiar with the procedure of the FEM for simple planar objects like truss and etc. but my question would be whether it would be possible to use this method to calculate the stiffness or ...
CommunityBot
- 1
0
votes
1
answer
13
views
Deformation in nano timescales for stress > UTS
I am investigating the deformation of high-strength carbon steel past its UTS, subject to extreme pressures of order 1e+19 Pa, but applied in small timescales (100-500 ns). For a material, such as ...
CommunityBot
- 1
0
votes
0
answers
24
views
Define material from Ogden–Holzapfel two-fiber strain-energy function in Ansys
I'm trying to do a FSI simulation with properties, described in this paper and for the structural properties, the authors use an Ogden–Holzapfel two-fiber strain-energy function to describe the solid ...
- 3
1
vote
1
answer
28
views
Displacement vectors and linearised angles vectors from local finite element frame to rotated global frame
$s=R\tilde{s}$ is fine, but why $\theta=R\tilde{\theta}$? Namely: why vectors of linearised rotations $\theta_i$ and $\theta_j$ (at nodes $I$ and $j$ respectively) are rotated like they were vector ...
CommunityBot
- 1
0
votes
1
answer
40
views
Iterative Method through FEM
Due to reasons, I can not fully describe the process explicitly so I will be using substitutes to represent the variables.
Nomenclature:
x - an independent variable
y - another independent variable
Fz ...
CommunityBot
- 1
0
votes
2
answers
3k
views
How to avoid contact penetration in Ansys?
I am trying to simulate contact between a flat rigid plate and a sphere. I am applying a load on the flat rigid plate and the sphere is flexible. How can I avoid this flat from penetrating into the ...
CommunityBot
- 1
1
vote
1
answer
208
views
Analytical solution of thermal stress in a bi-metallic cylinder
As a side project I have looked to solve using Python an analytical solution for one-dimensional transient heat transfer in a thick cylinder with cladding on the inside surface, wherein the fluid in ...
CommunityBot
- 1
0
votes
0
answers
14
views
Aligning stresses from one element to another from FEM
I have a Finite Element Model (FEM) and from this model I want to transform the stresses of one element such that they align to another element's axis.
Element A:
Centroid: [7195, 5151, 479]
...
1
vote
2
answers
254
views
FEM of beam with unsymmetrical UDL
I have two different UDLs for 6.5m and 3m spaced side by side on a primary beam. If I were to calculate the FEM of this beam, how should I proceed as there're no formulas for situation particularly ...
CommunityBot
- 1
2
votes
2
answers
161
views
Imposing/ensuring a constant mass flow rate in turbulent flow simulation
I'm trying to simulate using Finite Elements (non commercial software) the Tube Bundle benchmark problem:
http://cfd.mace.manchester.ac.uk/ercoftac/doku.php?id=cases:case078&s[]=tube&s[]=...
CommunityBot
- 1
0
votes
0
answers
12
views
Deformation Under High Pressure
If a FEA model suggests that a material deforms in a certain way for a max pressure of 1e+11, 1e+13, 1e+15, can it be suggested that the same "direction" of deformation would be true?
I have ...
- 21
1
vote
2
answers
64
views
Is there a specific way to simulate porous structures?
I tried to simulate an axial compression test for a lattice (porous) structure but It takes too much time and it doesn't give me the right answer (when I compare with experimental results). So, I was ...
CommunityBot
- 1
0
votes
2
answers
39
views
Benchmarking Geometrically Exact Beams: Clarification Needed on Material Density?
In an early paper on Simo, I came across an example titled "Cantilever 45-degree bend subject to fixed and follower end load". A force of $600N$ and $300N$ was applied at the end, resulting ...
- 806
0
votes
1
answer
81
views
FreeCAD: FemAnalysis Python module missing
After trying to execute the GMSH macro by psicofil I got an error:
...
CommunityBot
- 1
4
votes
2
answers
754
views
Interference fit problem in ANSYS Workbench 16.1 - how do I get rid of pressure/displacement raisers?
I have an interference fit problem of two perfect cylinders modelled in 2D using symmetry. The overall interface pressure is around 20MPa lower than the hand calculations and I get non-uniform ...
CommunityBot
- 1
0
votes
1
answer
26
views
Is there a way to program a buckling analysis of an arbitrary shape, using a standard programming language/libraries (not Abaqus)?
I am trying to develop a program in Python that runs a few different basic analyses for optimization like minimizing compliance and buckling. I want to use machine learning to try to develop a fast (...
- 1,077
2
votes
3
answers
3k
views
Viscoelasticity and Hyperelastic model, history and difference
Actually, I see some papers use viscoelasticity or hyperelastic model for the same materials. It seems to me that those models were invented in different eras, and the hyperelastic is a newer model ...
1
vote
1
answer
190
views
How to repeat on ABAQUS FEM simulations without reloading the mesh?
I would like to perform several FEM simulations on a given mesh with ABAQUS, where only the orientation of an element set would change in between.
Currently, I'm just generating several inp files (...
CommunityBot
- 1
0
votes
0
answers
25
views
Simulating the Impact of Bicycling on Hip Joint Cartilage
Sorry if this question comes off as obvious. I have more of a biology/clinical research background, and I have almost 0 experience with FEA.
I have 50 sequential data points of the hip joint angles of ...
- 101
0
votes
1
answer
64
views
Preliminary way to estimate damping quality factor (Q) from a SolidWorks FEM
I am analyzing the modal response of a structural FEM for a spacecraft structures course. I'm using Solidworks Simulation Premium. Need first mode to be above 40Hz and the damping Q-factor (quality ...
CommunityBot
- 1
6
votes
2
answers
337
views
How to analyze a bent beam: Stress concentration?
I am analyzing a beam, that has a bend in it. Intuitively and inspecting FEA results using a linear solver, there is a stress concentration at the bend of this I-beam.
The part was not a straight I-...
CommunityBot
- 1
1
vote
1
answer
553
views
Debugging Ansys ACT C# Extensions
I'm using the Ansys ACT Api with C# to create an extension for Ansys (Mechanical).
When developing the extension I need to build a dll file from C# code (using Visual Studio). My problem is that ...
CommunityBot
- 1
1
vote
1
answer
74
views
Are there any advantages of using BEM for contact problem over FEM, apart from lesser computational cost?
FEM - Finite Element Method
BEM - Boundary Element Method
If we had access to "enough" computational resources (to discretize the entire volume domain in FEM to the same degree of fineness, ...
CommunityBot
- 1
0
votes
0
answers
107
views
Boundary conditions for Clevis fork (linear elasticity)
consider the Clevis fork domain (see here for an image https://www.traceparts.com/it/product/camloc-motion-control-h1-stainless-steel-clevis?CatalogPath=TRACEPARTS%3ATP01001005&Product=10-12112014-...
- 1
0
votes
2
answers
91
views
Find amount of sliding between 2 surfaces
in my project I am required to find how much two surfaces slide against each other (to see how much it'll will rub against skin). Does anyone know how I can find these results?
Thanks
CommunityBot
- 1
1
vote
1
answer
85
views
Why is the amount of force/moment transfer occurring between bodies in FEA is independent of mesh size?
So I read somewhere that the mesh size won't effect the amount of force transfer occurring between bodies if several bodies are in contact, and a global force is applied somewhere. I wanted to know ...
CommunityBot
- 1
0
votes
0
answers
15
views
Clarification on the location of stress and strain output value in Abaqus
Today, I had a discussion with my teacher about the location of stress and strain output in Abaqus. I believe that Abaqus outputs stress and strain based on Gauss integration points. However, my ...
- 149
0
votes
0
answers
14
views
Designing a Torsional Rotary Flexure - Finite Element Freeware?
I am interested in designing and building a flexure based telescope tracking accessory. The core of the design would be what I think is called a "rotary flexure" or "Twist-it" or ...
0
votes
0
answers
10
views
How can I input the equation below in Abaqus （Operate on XY Data） with certain condition? Where fi=5+5i and frequency range is between 300-950; S=189
Where fi=5+5i and frequency range is between 300-950; S=189.
- 1
0
votes
0
answers
12
views
Boundary condition of vibrating flange in ANSYS mechanical
I have a structure with both sides a having flange. The vibration comes to plant from one of the flanges. The structure has it's own fixed support on its bottom, bearing its weight.
I assumed force is ...
- 9,642
0
votes
1
answer
54
views
What are the possible reasons that a finite element simulation would converge successfully at larger element sizes but not at smaller element sizes?
When running a finite element simulation that converges at larger element sizes but not at smaller element sizes, what are the potential sources of the problem? I am wondering in what areas must a ...
- 2,646
0
votes
0
answers
21
views
Mode shape directionality in Abaqus finite element analysis
For a coupled aero-structural analysis I'm working on, I have to extract the eigenvectors/mode shapes of my structure, so that I can run aerodynamic calculations on them. I have a parameter (in this ...
- 1