Questions tagged [finite-element-method]

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91 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
53 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
272 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
40 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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1answer
2k 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
462 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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1answer
99 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
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385 views

How to convert solid part to shell part in Abaqus?

I want to compare the same model with solid shape and shell shape, since my model is big, I am wondering if there is a way to convert the solid part into a shell in Abaqus easily without creating a ...
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1k views

Simply Supported beam with multiple point loads and distributed load [closed]

How can I solve this problem using FEM (longhand calculation)? I want to find deflections at each load point. This is not a homework problem. This is related to a project that I and my brother is ...
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1answer
361 views

How to get all forces and displacements values in abaqus and export it to excel?

I have made bridge model in Abaqus, I also have done experimental study and I have the load-displacement data from my experiment, I am now going to compare the results from Abaqus and the results ...
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1answer
273 views

How to obtain strain and stress values by editing abaqus input file?

I am currently working on abaqus modeling, I am trying to find a quick way to get the strain and stress values shown in the output file. What do I need to put in the .inp file? Does anyone know how ...
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2answers
3k views

How to Solve this error message on Abaqus 'time increment required is less than specified' and 'too many attempts made for this increment'?

I am currently working on my dissertation project using abaqus, my model is an arch bridge consisting of a shell and solid elements, there are concrete and steel materials also, I have checked all of ...
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1k 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 ...
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1answer
67 views

Are there other finite element types besides the usual?

By finite element type I specifically mean element geometry. I am aware of Beam/Strut, Quad, Tri, Tet & Hex but are there other types, eg a hexagonal prism, rhombihedral etc.. ?
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56 views

Plastic failure evaluation of steel using FEM

I would like to evaluate failure in steel using FEM, especially in geometries with stress concentrations (notches etc.). One possibility is to calculate the stress distribution using a purely linear ...
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0answers
332 views

Beam element stiffness matrix for variable area cross section with mass and shear center not coinciding

I would like to find the full (12 by 12) Timoshenko beam element stiffness matrix for a variable cross section with mass center axis and elastic center does not coincide. I have the full stiffness ...
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1answer
64 views

In an incremental nonlinear FE procedure does the material stiffness matrix need to be updated?

A typical nonlinear FE problem can be given by: \begin{equation} \mathbf{R} = \mathbf{K}\rho + \mathbf{F}_{NL}(\rho), \end{equation} where R is the vector of applied forces, K is the material or ...
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123 views

Can Ansys import parameters

In Ansys workbench is it possible to import parameters with part geometry? Eg. if I create part or assembly in Creo or SolidWorks and define parameters for this geometry, can I export parameters with ...
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1answer
697 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 ...
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2answers
71 views

What is a good method (equation) for locally refining a 1D grid at each end?

I have a grid that I plan to discretize in 1D. It extends from 0 to L using N nodes, and I need to refine it at each end. I plan to have something that looks as follows: I have tried the to specify ...
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1answer
110 views

Most efficient fillet design given an envelope (for stress)

If one has a specified allowed X length and Y height, into which a fillet can be placed to reduce stress concentrations, is there an equation which can be used to determine the optimal shape of the ...
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1answer
309 views

How to derive deformation gradient or displacement gradient?

In one of my project, I need deformation gradient or displacement gradient for some elements in my model that made by ABAQUS software and I can't find it directly, any suggestion or help would be ...
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85 views

Marching Voxel FEA Mesh

I'm working on an FEA model and my mesher uses a "Marching Voxel method" I'm wondering what the relationship is between mesh size and computation time is? I.e. if I half the mesh size (1mm to 0.5mm) ...
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0answers
27 views

Nitinol FEA using Advanced Simulation NX

Is there a tutorial on how to do non-linear FEA using Siemens Advanced Simulation NX (not remap) with Nitinol, preferably using sol 601. An example would be very helpful, I searched online but most ...
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1answer
118 views

Do triangular/area coordinates offer computational advantages for numerically integrated triangles?

Isoparametric triangular finite elements can be formulated using "triangular coordinates" $(\zeta_1, \zeta_2, \zeta_3)$, also sometimes called area/areal/barycentric coords, or using "Cartesian ...
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2answers
2k views

How to decide initial size increment in Abaqus Dynamic Implicit?

I am using Dynamic Implicit to model a rolling problem. But I am not really sure what to choose as Initial increment. The default suggestion by Abaqus is the step time.
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1answer
39 views

Variational Problem of slow steady flow of viscuous fluid in 2D

I have a Problem with a transformation. The energy function is the following: $$I(u_1,u_2,P)=\int_R [\frac{\mu}{2}(u_{i,j} + u_{j,i}) u_{i,j}-Pu_{i,i} dx_1 dx_2 - \int_R f_i u_i dx_1dx_2 +\int _S ...
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1answer
506 views

Solidworks Flow Simulation the Rotation option missing

I am looking for assistance to understand why, with SolidWorks 2017, in the "Flow Simulation wizard - Analysis Type" I have no "Rotation" option? What do I need to do in order to see it?. The "...
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1answer
358 views

How to use failure criteria in isotropic material (NASTRAN)

I'm quite new in NASTRAN enviroment, and I am wondering how to use failure criteria which I can define when creating my isotropic MAT1 material for 1D elements (like CBEAM). From the Quick Reference ...
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0answers
1k views

Creating a custom field output in ABAQUS

I want to create a custom field output in ABAQUS. For the purpose of proof on concept, I want to display the maximum shear stress as calculated from the Mohrs circle, as discussed here for a 2D shell. ...
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0answers
59 views

Best software for 3D modeling and simulation semiconductors? [closed]

Need to design 3D model of photodiode and calculate it (interaction light with semiconductor). What software product would be better for this objective and why? Important criteria: Big library ...
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2answers
72 views

How to find strain in an inclined member of a struss

I'm working through an FEA problem and I'm stuck. Question: How can I determine the strain in member 3 from displacements known at node 3? It's at 45 degrees, I know I should be using some $cos\...
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0answers
33 views

Pressure-volume relation of thin-walled shell [closed]

Attempt to edit into a more specific question as suggested by moderator: I would like define the shape and material properties of a 3D thin-walled shell/membrane-like structure (for instance a baloon)...
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0answers
561 views

how to release specific degree of freedom in ANSYS Workbench?

I'm designing a truss which has 9 elements in ANSYS Workbench. since it is a truss, all of the elements are truss elements and can not tolerate momentum. I used <...
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1answer
40 views

Validation of Lightweight Chassis (measuring deflection of structures/strain gauging)

How can we validate the structural integrity of a small lightweight chassis manufactured from 6063-T6 aluminium that has been welded and then heat treated (back to t6 condition)? A simple FEA model ...
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0answers
92 views

External FEA confirmation

The exact question Assuming you have outsourced a FEA of a structural design (steel tubes and sheet metal, bolts and welds design): What would you look for in the report to have confidence in the ...
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2answers
5k views

What is the difference between FEA and CFD?

Many of us think FEA is used for structural problems and CFD is used for fluid dynamics problems. But I have read that the above statement is wrong. So please explain the exact usage of those two.Also ...
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0answers
142 views

How to simulate Ground Penetrating Radar system?

We have a project which requires Ground Penetrating Radar(GPR). We got a student license of NI AWR software and Ansys HFSS (high frequency structural simulator). Are those the correct software for ...
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2answers
470 views

How could an MGA's frame/chassis best be improved?

As an assignment for my Automotive Engineering study, I have to practice manual FEM calculations. I'm free to choose whichever existing construction, and with that I have to make FEM analyses of both ...
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2answers
2k views

What is the physical interpretation of the eigenvalues of the stiffness matrix in the finite element method?

Given an equation of motion of an undamped system $\mathbf{M}\mathbf{\ddot{q}} + \mathbf{K}\mathbf{q} = \mathbf{f}$, $\mathbf{M}$ indicates the mass-matrix, $\mathbf{K}$ the stiffness matrix, $\mathbf{...
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2answers
631 views

How can I reduce the computation time required to simulate a brain tissue penetration model?

I am trying to model the strain generated by inserting an electrode device into brain tissue. I've had some success in doing this in ANSYS Explicit Dynamics. Here's a link to a GIF showing the ...
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0answers
296 views

“Set redefined” Error When Running a Restart Job in Abaqus 6.12-1

Using Abaqus 6.12-1, I am trying to submit a restart job with an added step. I've followed exactly the instructions in section 19.6.5 of Abaqus 6.12-1 CAE user's manual, but receive this error: A ...
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1answer
106 views

Pattern of zero stress in regular truss structure

I'm reading David Hutton's Finite Element Analysis, and recently programmed the truss analysis from scratch (in java). The figure shows the screenshot of a regular truss, with two ends fixed and a ...
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3answers
2k views

Inertia Relief and Buckling SOL105 in Nastran

Has anyone ever tried running buckling simulations in Nastran where inertia relief is invoked? I am just using a simple plate and I am getting "funny" modes (unrealistically low eigenvalues which ...
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1answer
1k views

How to incorporate moment release at beam end in FEM formulation?

I have a structure with a lot of interconnecting column and beam frame elements. I want to compute the displacement, member forces/moments via Finite Element Method. The problem now is that I don't ...
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1answer
2k views

ANSYS Workbench - Support type when lifting

Which type of support should I use when trying to simulate stress in structure that is lifted. Lifting is done by using four lifting lugs and chain angle is 45 degrees. What type of support to use on ...
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2answers
200 views

How to calculate rotations from displacements?

I'm trying to develop a finite conical shell element with six dof at each node. I want to express the rotations $\phi$, $\theta$ and $\psi$ in terms of the displacements $u$, $v$ and $w$. The ...
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3answers
493 views

Are linear beam element solutions ever exact and when are they used in practice?

In qualifying the results of a Finite Element (FE) beam model, I'm realizing that I dont understand FE beam elements as well as I should. Is there a procedure to determine what order beam element is ...
3
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1answer
938 views

What are exact location of Integration Points in STRI3 element in ABAQUS?

Introduction I have a file with .rpt extension from ABAQUS which is output of a model. This .rpt contains stresses of elements and displacements of nodes in plane text format. There is an item with ...
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1answer
160 views

FRF based material constant optimization

I need advice on how to optimize a finite element model of a transversely isotropic material. I have modeled the material with 5 nominal moduli in Abaqus and performed an eigenvalue extraction. ...