GRAPHICALLY-ORIENTED ANALYSIS OF BENT CAPS WITH MOVABLE LOADS ON MICROCOMPUTERS. FINAL REPORT

Bent Cap (CAP18) is a specialized beam-column program modified for use with AASHTO lane loading rules. It performs finite-element simulation of a linearly elastic beam-column subjected to fixed and movable loads. When Bent Cap is used for design, the following assumptions are built into the solution: (1) all supports are knife edged (pin connected), (2) no axial loads are present, (3) live loadings are varied in accordance with AASHTO rules, and (4) deck slab for slab and stringer construction is hinged over interior stringers. Enhancements are made to the existing FORTRAN code using a user-oriented method of analysis particularly suited to highway bridge bent caps. The original code runs on a minicomputer with alphanumeric terminals, while the enhanced version runs on a microcomputer with an improved user interface that includes panel-oriented input and extensive use of graphics. Low level assembly language routines are written to provide functions for manipulating screens, while calls to a commercial software package provide functions for graphical capabilities. The existing code is integrated with the new program as a subroutine, but no other modifications are made to facilitate avoidance of new error sources. Panel-oriented input eases the user's burden of creating and editing problems. Graphical representation of input data allows error checking before execution of the code. In addition to the conventional numerical presentation, output data from analysis are also displayed graphically. A menu structure controls access to various capabilities of the software package. FORTRAN 77 is used as the primary language for new code development.