Questions tagged [finite-element-method]
The finite-element-method tag has no usage guidance.
286
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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 ...
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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 ...
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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 ...
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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 (...
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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 ...
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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 ...
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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-...
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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 ...
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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 ...
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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.
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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 ...
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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 ...
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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 ...
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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 ...
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FEA of Rectangular Body Under the Effects of Combined Rotational and Translational Shear
First image is model setup. Clasp is rigidly constrained at top surface. Rectangular beam is affixed to clasp at clasp faces (locally constrained), by way of adhesive pads (second and third images).
...
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Theoretically when a homogeneous isotropic bar is subjected to axial loading, does it fail in shear?
I m referrencing James M Gere, Timoshenko Mechanics of Materials Chapter 2 Page 106. The book talks about effect of uniaxial load on a small element that is inclined in one axis. So my question is if ...
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Comparison between hand calculations of a continuous beam with FEA simulation (Solidworks)
I've seen many videos and books where statically determined beams' hand calculations are checked using FEA. But why is it that FEA results don't match the ones obtained using hand calculations (in ...
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A benchmark to check the validity of a finite element analysis
Is there any well-established benchmark to test the validity of a finite element analysis, i.e. FEA? For example, a 3D model with specific loading and boundary conditions. Along with the expected ...
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Residual Stress Induced By Shot Peening
I'm interested in the residual stress profile induced by shot peening. Most of the papers I have read do some measurement and include a graphic which looks like:
This graphic identifies how the ...
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Possible Modification to Contour Method for Residual Stress Measurement
I've been studying the contour method for measuring residual stress. See https://www.lanl.gov/contour/ if you are not familiar.
In the contour method, a single cut is made all the way through the ...
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Simulation of the direct piezoelectric effect using FEM
I have to simulate the direct piezoelectric effect, i.e. the generation of electrical charge under an applied mechanical strain using FEM with FEniCS. My geometry is a freestanding quadratic prism (a ...
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How can I recover the deformation gradient from the finite element strain result
I have performed a finite element simulation which corresponds to the example in https://de.wikipedia.org/wiki/Deformationsgradient#Beispiel .
The result from the theory in wikipedia is the following (...
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Using Strain Tensors to Recover Stress Tensors
Disclaimer:
I am very new to the field of mechanics, my background is in electrical engineering. I apologize in advance if anything is horribly wrong.
My references are:
"First Course in FEM, 4th ...
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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 ...
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Simulating oscillating loads on Ansys Workbench
I am working on a project to perform fatigue analysis and frequency analysis on a tandem bike that I modeled. How do I simulate the oscillating loads involved in pedalling?
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Hexamesh of a helical coil in ICEM CFD
I am trying to mesh a helical coil segment in ICEM CFD. My approach is to create a 3d block at the start of the geometry, and then extrude it along the center curve:
However, when I do this I end up ...
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Lifting a table using linear rails and linear actuators
I'm trying to design a coffee table for a tightly constrained space that can lift up to become a dining table. I've drawn the CAD for this design, but I'm concerned that the moment arm on the linear-...
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Units of measurement for structural analysis
FEA engine
I'm using CCX finite elements analysis engine along with its pre- and post-processor CGX:
http://www.dhondt.de/index.html
https://github.com/calculix
Example
I'm looking at one example here ...
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Wanting to solve an abaqus step many times with different material properties
I'm going to ask this question, and I am not even sure that what I have in my head is possible.
I have a model with 5 part instances. To understand the effect of material parameter values on part ...
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How does one post process in LS dyna for a seat belt?
Intro: I am looking to use LS Dyna to model a dummy crash.
I have done all the dummy positioning and set up but can not find any tutorials or info on the post process, boundary conditions and running ...
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How to calculate Strain Energy Density from Abaqus hyperelastic simulation?
I am modeling a deformation of a rubber material using Abaqus/Explicit using Ogden hyperelastic model. I can visualize Stress (S) and Displacements (U), but I am interested in plotting the strain ...
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How to add point mass in 3D mass matrix
I have a eigenfrequency simulation $ M * \ddot{\vec{x}} + K * \vec{x} = \vec{0} $
and want to add point masses to certain nodes. The only example I have is a 1D matrix where all of the mass at node 1 ...
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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 ...
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Abaqus error: Too many attempts for hyper-elastic pneumatic inflation simulation
I encounter the too many attempt error in my hyperelastic silicone rubber soft actuator inflation simulation. This is the original structure:
This is the air pressure load and Boundary constraint ...
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Effect of bracing on a music instrument top - is FEM modal analysis enough to predict this?
I'm currently building a music instrument (string instrument), and I am at the step where one applies certain braces to the soundboard. Since I actually don't know how the bracing will affect the ...
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Conversion of elastic moduli for plane stress case
For isotropic material an elastic modulus, like Young's modulus and in combination with a Poisson ratio can be used to convert to any other elastic modulus, like for example the bulk modulus. Tables ...
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Plate theory vs FEA
I’ve modelled a plate in Abaqus FEA, and I also calculated the Stress and deflection by hand using plate theory-
Why is it that plate theory and simulation deflection and Bon Mises stress values vary ...
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Ansys: Transient Thermal Analysis using Step Selected Element Birth and Death
I am trying to model the 3d printing process, where one bead of filament (represented by one element) is printed at a time. To do this, I am creating a geometry of 3 cube elements (block1, block2, and ...
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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 ...
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Why are square Intergrable functions bounded? How is it related to L2 functions and Hilbert spaces?
To approximate the weak form of linear elliptic pde to solve Elasticity problem, we use L2 functions and Hilbert space. In that, I read that Square integrable functions are bounded. Why is that true ...
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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, ...
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FreeCAD: FemAnalysis Python module missing
After trying to execute the GMSH macro by psicofil I got an error:
...
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What are the methods for assessing accuracy of FEM models?
What are the methods for assessing accuracy of FEM models?
That is, to guide the development of a FEM model, and finally for assessing its reliability, what kinds of practices are used?
Sometimes it ...
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What is the solutions of the following 1D diffusion equality using Crank–Nicolson method?
Through my research I faced to the following equality and need to find $c_i^{t+1}$. Moreover, I found that it can be solved by Crank–Nicolson method (see here: https://en.wikipedia.org/wiki/Crank%...
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Non-Linear Analysis Convergence Problem in Ansys
I am currently conducting a static structural analysis study in Ansys and encountered convergence prolems.
I have a very large thermal gradient (almost 600°C) as input from a precedent transient ...
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Boundary conditions for symmetrical problem of truss
What is the symmetrical problem for this truss, specifically the upper right part of it. What boundary conditions have to be added (i.e. supports).
What confused me was the specification for the upper ...
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Structured trianglar finite element mesh in MATALB
The available triangular mesh in the MATLAB PDE tool box here gives an unstructured triangular mesh.
How can I get a structured triangular mesh from the tool box with a similar data structure [p,e,t]. ...
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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 ...
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Why does the mesh size affect my modal analysis results?
The need for mesh refinement in a structural analysis module such as Static or Transient is quite clear; if we want the overall results such as displacement and stresses to be more accurate within the ...
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Can modern residual stress measurement replace finite element calculation?
Residual stresses are created by the manufacturing process and exist in materials and structures. Now, people develop many methods to measure residual stresses. Those methods can be divided into ...
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