Category Archives: FEM – Analysis

Finite Element Method
The finite element method (FEM) is a numerical technique for finding approximate solutions to boundary value problems for differential equations. It uses variational methods (the calculus of variations) to minimize an error function and produce a stable solution. Analogous to the idea that connecting many tiny straight lines can approximate a larger circle, FEM encompasses all the methods for connecting many simple element equations over many small subdomains, named finite elements, to approximate a more complex equation over a larger domain.

How to create Contacts with a BCTABLE Card by NASTRAN SOL101

For contact simulation between two structural components with MSC Nastran is necessary to perform a static analysis (Linear Simulation by SOL101 or Non Linear Simulation by SOL106) using CGAP elements with possible convergence problems. This type of modeling is complex because … Continue reading

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Strength Criteria of Composite Material supported by FEM analysis

Strength Criteria of Composite Material supported by FEM analysis Continue reading

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Static Condensation – FEM Analysis

Background Theory With “condensation” is indicated a procedure adopted for the structural analysis to carry out a matrix of stiffness and load boundary conditions of a detailed finite model (DFEM), starting from a raw global finite model (GFEM). The DFEM … Continue reading

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Contact simulation with MSC/Nastran

Linear Gap The linear GAP is the simpliest contact form used in Nastran simulations. Linear GAP can solve a large class of problems like hole bearing, heel-toe interaction, fitting contacts. Linear, therefore does not include frition, large displacements, and material … Continue reading

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Non linear Buckling with FEM approach

Buckling analysis assesses the stability characteristics of a structure. An accurate solution to a buckling problem requires more efforts than just following a numerical procedure, there are a number of factors to consider before a buckling solution can be accepted … Continue reading

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Buckling of an imperfection-sensitive cylindrical shell

Buckling of an imperfection-sensitive cylindrical shell (EXTRACTED FROM ABAQUS GUIDE) This example serves as a guide to performing a postbuckling analysis using Abaqus for an imperfection-sensitive structure. A structure is imperfection sensitive if small changes in an imperfection change the … Continue reading

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Nastran run in batch mode

Sometimes is necessary to perform several Nastran runs, and by running one by one could be necessary a lot of time. Hereafter are illustrated two methods to speed up these operations. There is an effective method to perform this operation … Continue reading

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Nastran launch commands

The Nastran solver is executed usually by command line like „nastran“. Generally it could be with different name,  due to the needs to specify the version of solver. The format nastran command is:   nastran2012  input_file  keyword1 = value1  keyword2 … Continue reading

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Vibration Analysis – Nastran SOL 103

Vibration Analysis – Nastran SOL 103 Continue reading

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Non Linear Analysis SOL 106

In the most of cases the nonlinear effects in structures occur due to nonlinear material behavior and large deformations. Geometric nonlinearity becomes relevant when the structure is subjected to large displacement and rotation. Geometric nonlinearity effects are prominent in two … Continue reading

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