NASTRAN USER’S MANUAL

The User’s Manual is one of four manuals that constitute the documentation for NASTRAN, the other three being the Theoretical Manual, the Programmer’s Manual and the Demonstration Problem Manual . Although the User’s Manual contains all of the information that is directly associated with the solution of problems with NASTRAN, the user will find it desirable to refer to the other manuals for assistance in the solution of specific user problems. The Theoretical Manual gives an excellent introduction to NASTRAN and presents developments of the analytical and numerical procedures that underlie the program. The User’s Manual is instructive and encyclopedic in nature, but is restricted to those items related to the use of NASTRAN that are generally independent of the computing system being used. Computer-dependent topics and information that is required for the maintenance and modification of the program are treated in the Programmer’s Manual. The Programmer’s Manual also provides a complete description of the program, including the mathematical equations implemented in the code. The Demonstration Problem Manual presents a discussion of the sample problems delivered w!th NASTRAN, thereby illustrating the formulation of the different types of prob’!emsthat can b~ solved with NASH?PN. In addition to the four manual~ described above, there is also a NASTRAN User’s Guide that serves as a handbook for users. It describes all of the NASTRAN features and options and illustrates them by examples. Other excellent sources for NASTRAN-related topics are the proceedings of the NASTRAN Users’ Colloquia (held normally every year) which provide a large body of information based on user experiences with NASTRAN. The User’s Manual has recently been completely revised and updated. With a view to facilitate easier updating of the manual in the future to keep up with newer releases of NASTRAN, it has now been divided into two volumes. Volume I consists of seven sections dIldcontains all of the material that was in the old single volume, except Section 3. This section has been re-arranged into four sections and forms Volume II. In order to avoid confusion, Section 3 of Volume I does not contain anything other than a reference to the new Volume II. Also, it should be noted here that, unless explicitly indicated ——.. otherwise, —. all —-—.. references — .... —.--. .. to .... sections .. ——.. in each —.——.—--- volume refer onl y to —— sections in ..——. that volume, . NASTRAN uses the finite element approach to structural modeling, wherein the distributed physical properties of a structure are represented by a finite number of structural elements which are interconnected at a finite number of grid points, to which loads are applied and for which displacements are’calculated. The procedures for defining and loading a structural model are described in Volume I, Section 1. This section contains a functional reference for every card that is used for structural modeling. The NASTRAN Data Deck, including the details for each of the data cards, is described in Volume I, Section 2. This section also discusses the NASTRAN control cards that are associated with the use of the program. As mentioned earlier, Volume I, Section 3 does not contain anything other than a reference to Volume II. The procedures for using the NASTRAN plotting capability are described in Volume I, Section 4. Both deformed and undeformed plots of the structural model are available. Response curves are also available for static, transient response, frequency response, modal flutter and modal aeroelastic response analyses. NASTRAN contains problem solution sequences, called rigid formats, Each of these rigid formats is associated with the solution of problems for a particular type of static or dynamic analysis. in addition to the rigid format procedures, the user may choose to write his own Direct Matrix Abstraction Program (DMAP), This procedure permits the user to execute a series of matrix operations of his choice along with any utility modules or executive operations that he may need. The rules governing the creation of DMAP programs are described in Volume I, Section 5. The NASTRAN diagnostic messages are documented and explained in Volume I, Section 6. The NASTRAN Dictionary, in Volume I, Section 7, contains descriptions of mnemonics, acronyms, phrases, and other commonly used NASTRAN terms. Volume II, Section 1 contains a general description of rigid format procedures. Specific instructions and information for the use of each rigid format are given in Volume II, Sections 2, 3 and 4, which deal with the rigid formats associated with the DISPLACEMENT, HEAT and AERO approaches, respectively. There is a limited number of sample problems included in the User’s Manual. However, a more comprehensive set of demonstration problems, at least one for each of the rigid formats, is described in the NASTRAN Demonstration Problem Manual, The data decks are available on tape for each of the computer systems on which NASTRAN has been implemented. Samples of the printer output and of structure plots and response plots can be obtained by executing these demonstration problems. The printer output for these problems is also available on microfiche.