Questions tagged [finite-element-method]
The finite-element-method tag has no usage guidance.
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how to get laminate stiffness matrices (ABD) in APDL ANSYS
I am trying to perform structural analysis of composite pressure vessel in APDL/ANSYS. I have completed the solution and now I want to extract ABD matrix.Do anyone have an idea about this?
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1answer
20 views
Shape Functions of beam element with 3 nodes (quadratic element)
For a two node beam element there are four shape functions for four degree of freedom:
For a straight three node beam element how shape functions are?
Please note that beam is straight and not ...
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13 views
Source for learning Functional derivative , Gateaux derivative
I have started doing research in optimal control theory. My area of research is PDE constrained optimization.
I am facing significant difficulty in deriving the Gateaux Derivative of functionals ...
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1answer
18 views
Can boundary layer theory be applied in finite element methods as it is applied in finite volume method?
Can boundary layer theory be applied in finite element methods as it is applied in finite volume method? i.e The flow away from the boundary is considered inviscid and solved first, then the flow ...
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1answer
19 views
Finite element method, question about the solver
So I am working with COMSOL Multiphysics and I have a very complex simulation. I have a boundary condition that evaluates to 1 if the value of a variable is 20 and 0 otherwise. I could implement my ...
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1answer
23 views
How to perform 3 point bending test by using force instead of displacement in ABAQUS?
I know you can apply displacement to a rigid body (cylindrical rod) to perform a 3 point bending test in ABAQUS. Is it possible to apply force to the rod (e.g. rod with super high young's modulus so ...
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1answer
40 views
How to introduce the CONSTITUTIVE equation into structure mechanics [closed]
Suppose I have stress and strain relationship and it can be simplified to the equation $\sigma=Function(\epsilon)$. This is the CONSTITUTIVE equation of the material I want to do research.
Assume ...
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0answers
58 views
How can I do engineering projects for money at home? [closed]
I am a M.Sc. graduate in mechanical engineering and I have experience with engineering software, like MATLAB, CATIA, and ABAQUS.
I want to know how I can find industrial projects like finite element ...
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1answer
30 views
Calculate surface area and outward normal of each face(non-planar) for a irregular hexahedron.
I am using the vector cross product to calculate each surface area and thus the outward normal. However, this approach fails when the surfaces are non-planar. So what is the best approach to calculate ...
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1answer
38 views
Stress Tensor decomposition into Compression & Tensile forces
I'm working on a project that does a finite element simulation of a mesh. I can output the stress tensor at each node, but I'm not so sure how to implement failure criteria.
If my material is brittle,...
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0answers
9 views
Is it possible to change a 'relaxing length' of edges for 8 node hexaedral element in 3d FEM
I am using 3D FEM with 8 node brick element to model a certain type of growth/expansion, which is not a plastic deformation. First, I apply a pressure/load and I get displacement and new position of ...
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0answers
30 views
Modelling radial Stiffness in Patran Usinf CBUSH Element
I am currently working on a project using MSC Nastran and Patran trying to model only radial stiffness between two hollow cylinders. I have been able to idealize a connection which has both radial and ...
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0answers
27 views
Force exerted on the CPU socket by heatsink
I am currently designing a replacement bracket for AM4 CPU coolers that will be compatible with different cooler models and allow them to be installed facing different directions, as AM4 socket is non-...
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0answers
20 views
Joint Revolute or Fixed?
a shaft is driven by a motor, it is supported in two places by ball bearings and connected in third place by a motor.
how can I use this example in Ansys WB?
1. variant : two places, where the bearing ...
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1answer
68 views
Model Reduction - ANSYS
I am trying to reduce my model in ANSYS using Craig-Bampton Method.
My ultimate goal is to read system matrices, stiffness, damping and mass matrix with MATLAB. I have been researching for a while, ...
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1answer
28 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 ...
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2answers
77 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 ...
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1answer
105 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 ...
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1answer
33 views
Boundary Conditions fro Static Structural Analysis of a Turbine Rotor Using FEM
I am trying to perform static structural analysis of a turbine rotor which is rotating at a given angular speed, say 1000 rad/s. I also know the pressure distribution from CFD analysis. What are the ...
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1answer
79 views
Should one use multiple elements through the thickness with multiple materials?
To get realistic results from a FEM calculation, it is common (or so I've been taught by someone who may not be up to date) to use at least four or five elements through the thickness of a beam or ...
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0answers
27 views
Bolted joint junker test with finite element method
Anybody knows a tutorial to make a finite element analysis for bolted joints like junker test(fastener vibration) in Solidworks or Ansys?
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0answers
44 views
Modeling Rotation and Translation of surface B.C. in Abaqus
I am trying to model a test which has grips that can translate in X and Y directions, as well as rotate. I have been trying to model this using constraints and a reference point but have not been able ...
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1answer
71 views
Strain gauge placement to measure a twisting beam
Where is it best to place a strain gauge to measure the twist of a beam? And what type of gauge is best?
In my application, I have a small metal part which experiences a twisting and bending force. ...
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1answer
40 views
How to calculate residual strength of a corroded structure from their stress values?
Currently, I have an actual entire corroded bridge model in the FEM analysis in Abaqus
I want to estimate the residual strength of this bridge due to corrosion
from the output results in the Abaqus, I ...
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1answer
76 views
How to prove that during loading session of glass container, which will happen first - overstressing or buckling - via FEA?
How do I prove that during a loading session of a glass container, between two failure modes, overstressing or buckling, which will happen first via FEA? Is there any scientific way of approaching ...
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1answer
118 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 ...
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0answers
35 views
Polyurethane tube simulation in Solidworks [closed]
I am doing polyurethane tube simulation in Solidworks Simulation. I am using material PUR for polyurethane already defined in Solidworks. I have a question about the model type to be selected for ...
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1answer
65 views
Should I apply Force or Pressure, Ansys Static Structural
I am working on a project where I must find the maximum principal stresses on an object subjected to impact loading condition. I know the velocity of the object (the one which will hit the test object)...
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0answers
43 views
Bad triangular-shell elements in Abaqus?
Abaqus 6.14
I have a 2D shell mesh reconstructed from a *.ply file. When I verify the mesh I get 55% bad elements (CPS3).
So I get a list of all the bad elements & reconstruct the mesh again ...
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0answers
61 views
Abaqus implicit dynamic vs custom script
I'm trying to validate results from a custom code written with Matlab by comparing the results with Abaqus. I'm doing an implicit dynamic analysis using direct integration and, as done in Abaqus, I'm ...
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1answer
45 views
Predicting frequencies, decays, levels, and phases of modes of a circular membrane (drum head)?
I have been working on some acoustic synthesis software for modelling several acoustic instruments. I am using the principle of modal synthesis, where every mode of vibration is individually ...
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1answer
142 views
Spatially dependent material property in Abaqus/CAE
I am modelling a plate as 3D deformable solid. My plate has a spatially dependent isotropic thermal expansion coefficient.
I have defined this spatial distribution as a Discrete Field in a tabular ...
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0answers
25 views
Where to fix part in moment setup for FEA
I'm working on a project that involves supporting a distributed load on a bar that is held up by a moment at one end of a lever arm. My goal is to assess how much the bar bends under the distributed ...
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1answer
28 views
FEM: What's D in the equation for half band width
In the equation for half band width given below,
B = (D + 1)f
my textbook states D to be the maximum difference between node numbers in an element and all the elements are considered for its ...
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1answer
27 views
Do finite elements have to be planar?
Is it possible to define a finite element that isn't planar? For example the shell element shown in the picture below...
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0answers
16 views
Reasons for different analytical and simulated Young's modulus calculations
What can be some reasons for getting big differences in the analytical and simulated calculations of Young's modulus? Except just doing it wrong that is. Think around 30% difference for example.
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1answer
53 views
Cantilever beam with disc at end (structural mechanics)
I am trying to figure out how I can assemble multiple finite elements to obtain the system mass matrix $\boldsymbol{M}$ and the stiffness matrix $\boldsymbol{K}$.
The situation is depicted in a ...
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26 views
How can I define temporary contacts in Ansys?
For a special simulation I need to define a temporary contact between three objects that two of them are perpendicular to one of them and the two push the one step by step. When they are at rest, ...
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0answers
323 views
How does Abaqus calculate reaction force?
I wrote a UEL for one element and compared to a reference UEL (FEM), where the results agreed satisfactorily, except the reaction force. The stress, strain, strain energy all were pretty accurate.
I ...
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1answer
92 views
How to create a non uniform pressure load in MSC Patran
I need to simulate an external pressure load that varies sinusoidally along a circular arc. The sinusoidal variation is with arc length.
I know how to create a uniform pressure load in Patran but do ...
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0answers
29 views
Searching for Anterior Cruciate Ligament MRI Images for Finite Element Model.
I'm searching for 3D MRI images for generating an mesh to be used in a Finite Element Modeling project. My group has access to a low-resolution CT scan and cadaver knees, but we don't have any good ...
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0answers
45 views
Is it possible to design solid slabs on ETABS 2016? [closed]
My graduation project involves designing several buildings with flat and solid slabs. I already know that ETABS can design flat slabs but is it possible to design solid slabs?
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1answer
48 views
Why doesnt steel melt when pouring titanium through it
How come you can pour molten titanium with a melting point of 3291 degrees into a steel funnel with a melting point of 1300 degrees and it doesn't melt the funnel?
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1answer
77 views
in keyword *SURFACE, file “FSECase1cor.inp”, line 79025: Unknown assembly element set_M_SURF-1016_E3 (What does this error mean?)
I submitted the edited inp. file in abaqus. I edited the thickness of shell elements
then after I run the edited inp. file, I am suffering from this error.
Actually, there is another error:
"There ...
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1answer
28 views
How to properly validate transverse isotropic elasticity Finite Element Code
I have written a piece of code solving the linear elasticity problem on transversely isotropic materials (before that, the code only supported isotropic materials).
I would like to validate it before ...
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0answers
132 views
FEA Modelling of wood
I am working on designing an item for my local circus, a teeterboard (essentially a see-saw that people jump on each and it launches them in to the air to do flips etc)
.
I am working to get it ...
2
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1answer
598 views
ABAQUS Analysis: Difference between assigning Section as Plane stress/strain vs. Element type?
In ABAQUS, there are multiple ways to specif your part is in plane stress/strain.
1. When assigning the section, one can specify that it is a generalized plane strain section.
2. When assigning the ...
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1answer
181 views
Cyclic loading on ABAQUS CAE
I am new to abaqus and for my final year project I'm meant to simulate a force on a cylinder (testing displacement of articular cartilage) ranging from 1-15 Hz and between 15-36 Newtons but I don'...
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33 views
what is the quickest way to edit shell thickness from each mesh element in Abaqus?
I am currently trying to edit the uniform thickness in shell element in abaqus to non-uniform thickness for each element according to the mesh size.
I am wondering if there is an easy way to make non-...
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1answer
44 views
How to know which constraints suffer from 'nodes are used more than once as slave node' in abaqus?
I have been struggling to find which node and constraint suffering from 'nodes are used more than once as a slave node' in abaqus error message.
Please help me resolve this problem
Thank you
