Contact Modelling in Femap with NX Nastran Femap with NX Nastran enables more convenient contact modelling than has been traditionally available from general purpose FEA codes. For linear (small motion interfaces with or without friction) and general 3D non-linear contact, Femap with NX Nastran provides comprehensive modelling and analysis capabilities. General 3D contact can be with or without other types of non-linearity (such as large strain material plasticity) in static or transient environments.
For an overview of contact setup and common tips, click contact modelling.
Overcoming Model Singularities in NX Nastran (or any other finite element system) Model singularities are the cause of many common analysis error messages reported, and can be a source of frustration for many inexperienced (and experienced) analysts. For a discussion of how to recognise and overcome analysis singularities, click Overcoming Singularities.
Consistent Engineering Units in Finite Element Analysis Depending on the modelling software used for Finite Element Analysis (FEA), the modelling process often requires a very high level understanding of engineering units. Although FEA user interfaces may provide convenient methods for declaring which units are applied at any instant, it is important to know that almost every FEA solver does not show units in the "input file". For an understanding of consistent units in the context of FEA, click Engineering Units in FEA.
Nonlinear Analysis Restarts in Nastran It is not always necessary to rerun an analysis in its entirety to obtain additional analysis results, add a new load at a specific point in the analysis sequence, or even change the number of load steps used to apply the loads. For a discussion and example of how this can be managed in a restart analysis, click Nonlinear Restarts.
Concise Guide to Nastran Rigid Elements
A rigid element is a link from one node to another (or multiple nodes), where motion is governed by the "degrees of freedom" one chooses to connect. This guide describes common uses and tips for using these elements. It is practical rather than theoretical; however some theory is used to help better understand their practical use. For an appreciation of Rigid Elements, click Rigid Elements.
