A computer adaptive language for the development of structural analysis programs

Abstract

A group of FORTRAN 77 subroutines is presented which are designed to augment the standard fortran language and to produce a new higher-order, machine-independent language for the development of structural engineering software. The group of subroutines which comprise the Computer Adaptive Language for the development of Structural Analysis Programs, CAL/SAP, is designed to operate effectively on micro, supermini and mainframe computers. The CAL/SAP system has been used as the basis for the development of the SAP-80 series of programs and for CAL-80, a series of interactive programs for Computer Assisted Learning of structural analysis and design. The subroutines which define the CAL/SAP development system are divided into the following three categories: • • First, a series of free-field input routines allows input data to be specified in a consistent manner, in arbitrary order, with optional name identification and in arithmetic statement form. • • Second, a set of incore data management subroutines allows dynamic storage allocation to be accomplished with integer, real and ASCII data with a minimum of programming effort. These subroutines eliminate paging problems on modern super minicomputers with virtual operating systems. • • Third, an out-of-core data management system allows different programs to access the same data. Simple operations allow data transfer between the in and out-of-core systems. The out-of-core data base provides for sequential, direct access and bulk data files. Communication between different data bases allows techniques such as multilevel substructure analysis to be implemented with a minimum of programming. The use of the CAL/SAP development system allows computer programs to be rapidly developed and maintained. Also, it can be used to upgrade existing software in order to obtain modularity and to operate efficiently on the new generation of computer systems. The purpose of this paper is to present the CAL/SAP development system and to illustrate that computer independent programs in structural engineering and computational mechanics can be developed which operate on both large and small computers.