Abaqus Theory Guide

The objective of this guide is to define the theories used in Abaqus that are generally not available in the standard textbooks on mechanics, structures, and finite elements but are well known to the engineer who uses Abaqus.

The guide is intended as a reference document that defines what is available in the code. Nevertheless, it is written in such a way that it can also be used as a tutorial document by a reader who needs to obtain some background in an unfamiliar area. The material is presented in a way that should make it accessible to any user with an engineering background. Some of the theories may be relatively unfamiliar to such a user; for example, few engineering curricula provide extensive background in plasticity, shell theory, finite deformations of solids, or the analysis of porous media. Yet Abaqus contains capabilities for all of these models and many others. The guide is far from comprehensive in its coverage of such topics: in this sense it is only a reference volume. The user is strongly encouraged to pursue topics of interest through texts and papers. References at the end of this guide lists references that should provide a starting point for obtaining such information. (Abaqus does not supply copies of papers that have appeared in publications other than those of Abaqus. EPRI reports can be obtained from Research Reports Center (RRC), Box 50490, Palo Alto, CA 94303.)

Many sections in this guide apply to both Abaqus/Standard and Abaqus/Explicit, although certain sections apply only to either Abaqus/Standard or Abaqus/Explicit; for example, all sections in Procedures apply to Abaqus/Standard except the section discussing the explicit dynamic integration procedure, which applies to Abaqus/Explicit. The applicable products are indicated in each section.

Introduction and Basic Equations discusses the notation used in the guide, some basic concepts of kinematics and mechanics—such as rotations, stress, and equilibrium—as well as the basic equations of nonlinear finite element analysis. Procedures describes the various analysis procedures (nonlinear static stress analysis, dynamics, eigenvalue extraction, etc.) that are available in Abaqus. Elements describes the element formulations. Mechanical Constitutive Theories describes the mechanical constitutive theories.

Interface Modeling discusses the most important aspects of the contact/interaction formulation in Abaqus/Standard. Loading and Constraints describes the formulation of some of the more complicated load types and multi-point constraints.