ProductsAbaqus/StandardAbaqus/Explicit The input fileAn Abaqus input file is an ASCII data file. It can be created by using a text editor or by using a graphical preprocessor such as Abaqus/CAE. The input file consists of a series of lines containing Abaqus options (keyword lines) and data (data lines). The input syntax for keyword and data lines is described in Input Syntax Rules. Most input files have the same basic structure. The following portions of the input file are specified to define a finite element model:
The input file is processed by the “analysis input file processor” prior to executing the appropriate analysis product, Abaqus/Standard or Abaqus/Explicit. The functions of the analysis input file processor are to interpret the Abaqus options, to perform the necessary consistency checking, and to prepare the data for the analysis products. Most computational mechanics modeling options (element types, loading types, etc.) are available in both Abaqus/Standard and Abaqus/Explicit, although some options are available in only one analysis product or the other. All of the step procedure types used in an input file must be from the same analysis product; however, it is possible to import a solution from Abaqus/Standard into Abaqus/Explicit and vice versa (see Importing and transferring results), which allows each analysis product to be used at the various stages of an analysis for which it is best suited (for example, a static preloading in Abaqus/Standard followed by a dynamic analysis in Abaqus/Explicit). Model dataModel data define the nodes, elements, materials, initial conditions, etc. Required model dataThe following model data must be included in an input file to define a finite element model:
Optional model dataThe following model data can be included as necessary:
History dataThe purpose of an analysis is to predict the response of a model to some form of external loading or to some nonequilibrium initial conditions. An Abaqus analysis is based on the concept of steps, which are described in the history data portion of the input file. (For more information on steps, see Defining an analysis.) The history input data are combined within a step as needed to define the history of the analysis. Multiple steps can be defined in an analysis. Steps can be introduced simply to change the output requests or to change the loads, boundary conditions, analysis procedure, etc. There is no limit on the number of steps in an analysis. There are two kinds of steps in Abaqus: general response analysis steps, which can be linear or nonlinear; and, in Abaqus/Standard, linear perturbation steps (see General and perturbation procedures). A general analysis step contributes to the response history of the system; a linear perturbation step allows the investigation of the perturbation response of the system with respect to a base state at any stage during the response history. The solution from the perturbation response is not carried over to subsequent steps and, therefore, does not contribute to the response history. The state at the end of a general step provides the initial conditions for the next step, making it easy to simulate consecutive loadings of a model, such as a dynamic response following a static preload or the loading of a product during its usage following a simulation of the manufacturing process. The optional history data described below prescribing the loading; boundary conditions; output controls; auxiliary controls; and, in Abaqus/Explicit, contact conditions are continued from one general analysis step to the next general analysis step unless modified. For example, the solution controls prescribed in a general analysis step in Abaqus/Standard (see About convergence and time integration criteria) will remain in effect for all subsequent general analysis steps until they are modified or reset. For linear perturbation steps only the output controls are continued from one linear perturbation step to the next if there are no intermediate general analysis steps and the output controls are not redefined (see About Output). Required history dataThe following history data must be included in an input file to define an analysis procedure:
Optional history dataThe following history data can be included as necessary:
Including model or history data from an external fileYou can specify an external file that contains a portion of the Abaqus input file. This file can include model and history definition data, comment lines, and other references to external files. When a reference to an external file is encountered, Abaqus will immediately process the data within the specified file. When the end-of-file is reached, Abaqus will return to processing the original file. A maximum of five levels of nested external file references can be used. Linux environment variables can be used to specify the file names. Input File Usage INCLUDE, INPUT=file_name Including an encrypted data fileYou can include an encrypted file by reference in an Abaqus input file or in another data file. When you refer to the encrypted file, you must also provide the file's password. If the password is correct, Abaqus processes the data within the specified file as it would for an unencrypted external file. Material and connector behavior definitions within an encrypted input file are not written to the output database. In addition, all material and connector behavior definitions output to the data file are suppressed if an encrypted file is used as input for any portion of the model. See Encrypting and decrypting Abaqus input data for details about the encryption utility. Some encrypted files are eligible for inclusion only by users with a license for a particular Abaqus feature (such as Abaqus/Explicit) or to users at a particular site. If you attempt to include an encrypted file for which you do not have the proper privileges, Abaqus issues an error message. You cannot include encrypted input files that contain parametric input. Input File Usage INCLUDE, INPUT=file_name, PASSWORD=password |