Methods and systems for conducting a time-marching numerical simulation of a structure expected to experience metal necking failure

Abstract

A FEA model, representing a structure, contains at least many finite elements for metal portion, a set of metal necking failure criteria (critical and fracture strain values defined in form of a loading path diagram) and the neck s characteristics (neck s width and a profile of strain values within the width) are received in a computer system. At each solution cycle of a time-marching simulation using the FEA model, following operations are performed at each integration point of every finite element: identifying major and minor strain values and corresponding directions from the computed strain values, calculating an equivalent metal necking failure strain value (E e) in the major strain direction with a formula based on corresponding critical and fracture strain values, the neck s characteristics and a characteristic dimension with respect to the major strain direction, and determining metal necking failure, which occurs when the major strain value is greater than E e.

Description

technical field [0001] The present invention relates generally to computer-aided engineering analysis, and more particularly to methods and systems for performing time-marching numerical simulations of structures expected to experience metal necking failure. Background technique [0002] Computer Aided Engineering Analysis (CAE) has been used to support engineers in many tasks. For example, in structural or engineering product design programs, CAE analysis, especially finite element analysis (FEA), has often been used to predict structural behavior (e.g., stress, displacement, etc.). [0003] To numerically simulate metal necking failures in finite element analysis, users of FEA specify failure criteria. Prior art methods have evolved from physical metal sample testing using the average strain around the neck in a metal necking failure (eg, based on data obtained from the average strain measured with a strain gauge). As a result, the user needs to specify a set of metal n...

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Problems solved by technology

These prior art methods often lead to confusion and difficulty in preparing input data and lead to incorrect simulations because users need to prepare failure criteria based on these unreal and ad hoc requirements

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