Quick Start Guide

to midas NFXThis guide is made for non-experienced FEA users. It provides basic knowledge needed to run midas NFX successfully and begin your analysis.

Experienced FEA analysts can also use this guide to get used to the NFX workflow.

About FEA analysis……………………….1

Designer and Analyst mode ...........……..2

Import a CAD Model ……………………...3

Simplify your model …………………........4

Materials ..……………………………....….5

Contacts………………………………...…..6

Boundary conditions……………………….7

Loads………………………………………..8

Meshing…………………………………......9

Choose analysis and solve……………....10

View results……………………………......11

TABLE OF CONTENTS:

The Finite element method is an approximate method. It is

used when things get too complex and theoretical solutions

can not be easily obtained.

Firstly, it divides the target object into a large but finite

number of elements that we can control. Then it calculates

the properties of each individual element, and finally the

properties of the entire object are obtained by combining all

the elements together.

What is the Finite Element Method?

Page1

Physical Model Finite Element Model

Element

Node

Node and Element

1

Depending on your FEA experience, midas NFX provides 2

different working modes: Designer Mode and Analyst Mode

Designer and Analyst Modes

Page 2

2

Designer Mode

midas NFX (Analyst Mode)

Designer Mode

Designer-oriented interface

and automated functions

which help designers to

analyze 3D CAD models

simply and quickly.

Analyst Mode

Provides all the advanced

tools needed by FEA

professional analysts

(1D,2D,3D Geometry

Modelling, Manual Meshing…)

You can easily switch

between the 2 modes at the

upper-right hand corner

Analyst Mode

Switch between 2 modes

While importing a CAD model to NFX, pay attention to 2

points:

1. Select the right type of CAD model before importing.

2. Make sure that the length unit is identical to the CAD

model.

Import a CAD model

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3

1. Here to choose the file type

2. Here to check the length unit

Original CAD models usually contain small details(small fillets,

edges, holes, surfaces) .

Contrary to what one might believe, these details add no

benefits to the simulation. Instead, they lead to inaccurate FEA

model or models with too many meshes.

Therefore, to perform faster and more accurate simulations,

simplification work on the CAD model is often necessary.

NFX provides automatic tools to simplify your model and

get it ready for analyzing faster.

Simplify Your Model

Page 4

4

Materials can be divided into linear and nonlinear (elasto-

plastic, hyper-elastic, temperature dependant) materials.

Materials can also be isotropic, orthotropic or anisotropic.

To perform simple analysis on linear materials, only 3 basic

constants are required: elastic modulus, poisson's ratio and

mass density.

Midas NFX integrates a database of over 1000 materials.

Materials5

Page 5

3 basic constants

Choose linearity

Select from material database

By linking nodes of different mesh sets (mechanical parts),

contacts are necessary when analyzing a mechanical

Assembly.

Contacts are divided into linear (welded, sliding) and nonlinear

(general, rough, breaking-weld) contacts.

midas NFX provides auto-contact assignment which detects

and assigns contacts automatically to a mechanical assembly.

A singularity error may appear during the solving phase if

contacts are badly assigned or overlooked.

Contacts6

Page 6

Boundary conditions fix the degrees of freedom (DOF) of the

assembly. They can be applied on parts, surfaces, edges,

points or nodes.

In static analysis all DOFs need to be removed. If a free

translation or rotation is present in the model, singularity error

will occur during the solving phase.

Boundary Conditions7

Boundary Menu

(Designer Mode)

Basic Method

Boundary Menu

(Analyst Mode)

User Defined Method

Page 7

Loads can be divided into static, dynamic and heat load.

The choice of the type of load depends on the analysis to be

performed. Midas NFX provides easy way’s to choose and

assign loads to your model.

Loads8

Static Loads

Dynamic Loads

Heat Loads

Page 8

Meshing is the most important step in FEA model creation. The

mesh quality directly effects the quality and efficiency of the

analysis. If the mesh is to big or deformed then it will cause

inaccuracy in the results. To small a mesh and your calculation

time will double.

In midas NFX, meshing can be done either automatically or

manually depending on the quality requirements.

In Analyst Mode, the mesh quality can be checked with some

criteria such as aspect ratio to assure the quality of the mesh.

Meshing9

Auto -mesh Check mesh quality

Page 9

After preparing your FEA model, it’s ready to go onto the

solving phase.

Midas NFX provides various analysis types (linear/ nonlinear/

dynamic/ CFD) all in one interface. You can choose the right

one easily in the analysis case settings window.

The solver is the part of the software that takes the data

entered in the interface, as an input to run finite element

numerical algorithms and calculate the output.

Analysis Type and Solver10

Page 10

At last we come to the phase where you view the analysis

results. This task is charged by the post-processor in the

software.

Visualizing and interpreting the results in a good way is as

important as calculating the results themselves.

Various options and tools are proposed in midas NFX to

extract the correct analysis data.

View results11

Page 11

Now you are ready to go !”

Please contact us if you have any questions

during your trial:

Email: info@midasfea.com

Telephone: +44 (0) 1908 776717