This handbook is part of a series aimed at assisting in the development of robust and practical quality systems for engineering simulation. An important prerequisite for readers is the NAFEMS Simulation Handbook - Quality Management (hereafter ‘The Quality Management Handbook’.) This discusses quality principles in general and gives guidance on their practical implementation.

Having read The Quality Management Handbook, it is hoped that the specific examples of this application-specific handbook will serve as starting points in the development of a simulation team’s own Quality procedures and documentation set, to facilitate more robust and cost-effective analysis.

Introduction

This handbook gives guidance on best practice, specifically in linear static structural simulation using the finite element approach embodied in any of the commercially available numerical simulation packages. The technical discussions endeavour to cover, in some detail, many of the pitfalls (or procedural errors) that might impede the development of robust and effective linear static simulation strategies. It also attempts to describe good practice in the various stages of a simulation so that the anticipated (numerical and idealisation) errors can be reduced.

The examples of hypothetical documentation include sample procedures, plans and specifications and are illustrative of the author’s experience of development of a wide variety of linear static simulations, in several industries.There are three forms of simulation error described in The Quality Management Handbook: idealisation error, discretisation (or numerical) error and procedural error.The first two of these are anticipated features of the simulation process and are treated using validation and verification, which should be incorporated into any critical simulation procedure. The third type of error, procedural error, is controlled by devising and following procedures or work instructions, as part of a quality management system.Many of the common sources of error associated with the different stages of a linear static engineering simulation are described in this handbook. The various sections give background information followed by comments on good practice and warnings against common pitfalls. These should provide the analyst or manager with an understanding of how errors, whether anticipated or not, can arise and for anticipated errors, possible methods for their control and measurement during the validation and verification stages.

Different sections of this handbook will impact the elimination of error, whether idealisation, numerical or procedural. Section 2 covers the applicability of linear statics and in so doing, can avoid its inappropriate application. Section 3 covers geometry management and this is best seen as a means of avoiding procedural error by importing or creating accurate and appropriately detailed geometry. Section 4 discusses element types and model dimensionality. Selecting the correct element type for the model is an idealisation topic and affects the corresponding errors. Section 5, 6 and 7 cover element behaviours, meshing and solving. This encompasses most forms of numerical error in linear statics. Section 8 covers different forms of boundary conditions. This is both a procedural and idealisation issue. Section 0 discusses results and their presentation, which may introduce both numerical and potentially procedural error.

Contents