Quick Start Guide to midas NFX

Transcription

1 Quick Start Guide to midas NFX This 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.

2 TABLE OF CONTENTS: About FEA analysis.1 Designer and Analyst mode Import a CAD Model...3 Simplify your model...4 Materials Contacts Boundary conditions.7 Loads..8 Meshing...9 Choose analysis and solve...10 View results...11

3 1 What is the Finite Element Method? Node Element Physical Model Finite Element Model Node and Element 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. Page1

4 2 Designer and Analyst Modes Depending on your FEA experience, midas NFX provides 2 different working modes: Designer Mode and Analyst Mode Designer Mode Designer-oriented interface and automated functions which help designers to analyze 3D CAD models simply and quickly. Designer Mode Analyst Mode Provides all the advanced tools needed by FEA professional analysts (1D,2D,3D Geometry Modelling, Manual Meshing ) Analyst Mode You can easily switch between the 2 modes at the upper-right hand corner midas NFX (Analyst Mode) Switch between 2 modes Page 2

5 3 Import a CAD model 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. 1. Here to choose the file type 2. Here to check the length unit Page 3

6 4 Simplify Your Model 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. Page 4

7 5 Materials Materials can be divided into linear and nonlinear (elastoplastic, 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. Choose linearity 3 basic constants Select from material database Page 5

8 6 Contacts 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. Page 6

9 7 Boundary Conditions 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 Menu (Designer Mode) Boundary Menu (Analyst Mode) User Defined Method Basic Method Page 7

10 8 Loads 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. Static Loads Dynamic Loads Heat Loads Page 8

11 9 Meshing 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. Auto -mesh Check mesh quality Page 9

12 10 Analysis Type and Solver 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. Page 10

13 11 View results 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. Page 11

14 Now you are ready to go! Please contact us if you have any questions during your trial: Telephone: +44 (0)