Questions tagged [finite-element-method]
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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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How to find an expression or a formula to calculate the deflection of a solar sail (circular plate)?
the deflection of a solar sail needs to be analyzed in the software abaqus (FEM I ) and for that a sort of expression needs to be determined in order to get proper results
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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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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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FreeCAD: FemAnalysis Python module missing
After trying to execute the GMSH macro by psicofil I got an error:
...
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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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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 ...
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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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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 (...
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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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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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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-...
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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 ...
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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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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
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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 ...
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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 ...
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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 ...
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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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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 ...
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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 ...
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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 ...
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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.
...
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Find hotspots in a system
In the image, I have a depicted a system which is undergoing fatigue. Using appropriate solver I have determined the life of each nodes and it is stored in a .csv file. Also I have the connectivity of ...
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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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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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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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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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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 ...
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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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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 ...
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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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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 ...
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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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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[]=...
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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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How do I use FEM to derive the torsional constant of an arbitrary shape?
In this question I ask about how to perform a first-principle derivation of the torsional constant of a section. It appears that there is no such analytical derivation for torsional constant, so my ...
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How do I get the modes shapes (that I got from FEA of a system) in reality?
In FEA, I have a complex system onto which I have applied some boundary conditions and then conducted a modal analysis for it. In return, I got a few mode shapes (as much as I requested) for each of ...
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How to find the angle of deformation in Ansys APDL?
After solving my problem in APDL, and started doing some post-processing, I want to find how much the deformed shape has rotated (i.e. the maximum angle the furthest node has made comparing with the ...
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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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What is the difference between implicit and explicit analysis in ABAQUS?
How can I choose between Implicit or Explicit Analysis in ABAQUS for a simple rectangular composite structure with 2 layers of unidirectional lamina? I am trying to do a linear-static analysis to ...
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What are the governing equations solved in FEA for structural mechanics?
In CFD we focus on the NS equations as the governing equations (together with other equations) and solved them using Some numerical method (usually FVM). What are the governing equations (counter ...
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FEA Help: Reference point in abaqus at mid length
I am trying to place a reference point (for interation and coupling) on the axis and the mid height of the cylinder. Please tell me if there is a better way then giving manual coordinates. Thank you.
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Solidworks- Display the values of the drawn line beam
Dear all, in Solidworks, if I want to display all the von-misses stress value along the line I have drawn here (as this is the average stress which is useful), may I ask how I should do it? I have ...
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Crack Width Calculation through Section Analysis for a Section Experiencing Nonlinear Stress Profile
Ultimately, my goal is to calculate crack width at the stem.
I made this SAP2000 hollow pier model with solid brick elements to analyze the stresses and tried to calculate crack width in AdSec with ...
