This archive contains a collection of reports generated by the faculty and students of the Institute for Systems Research (ISR), a permanent, interdisciplinary research unit in the A. James Clark School of Engineering at the University of Maryland. ISR-based projects are conducted through partnerships with industry and government, bringing together faculty and students from multiple academic departments and colleges across the university.
Browsing Institute for Systems Research Technical Reports by Author "Albrecht, Pedro"
(1990) Creighton, Steven L.; Austin, Mark; Albrecht, Pedro; ISR
Historically, the lack of interactive pre-processors to setup tedious finite element problem descriptions has hindered the use of the finite element method for bridge analysis. The work performed in the present study mitigates this problem via the use of highspeed engineering workstations. This report presents an interactive, graphically based pre-processor for the analysis of highway bridges with the finite element method. With the pre- processor, bridge design engineers can use both keyboard and mouse styles of interaction to describe bridge geometries. The UNIX tool YACC has been used to create a command language for describing and manipulating of structural geometries, material types, loads, and boundary conditions. The pre-processor was successfully used to create input files in a format acceptable to the finite element analysis program ANSYS. In fact, less than 20 minutes was needed to create a finite element model of the prototype bridge tested at the Turner-Fairbanks Laboratory in Langley, Virginia, in a joint FHWA-AISI project. This report describes the development of the pre-processor in words that can hopefully be understood by civil engineers and computer scientists alike.
(1992) Austin, Mark; Creighton, Steven L.; Albrecht, Pedro; ISR
Historically, the lack of interactive pre-processors to describe tedious finite element models has hindered the use of the finite element method for bridge analysis. The work performed in the present study mitigates this problem by providing an interactive graphically based pre-processor for the finite element analysis of highway bridges with high-speed engineering workstations. The name of the pre-processor is XBUILD. Version 1 of XBUILD is written in the C programming language, uses Sun View graphics, and runs on SUN SPARCstations. The pre-processor gives engineers the choice of using both keyboard and mouse styles of interaction to describe and edit bridge geometries, set boundary conditions, define sub-structure and highway vehicle objects, and place trucks at desired positions on the bridge. The capabilities of XBUILD Version 1 are demonstrated by working through the step-by- step details of creating a finite element model for the FHWA-AISI test bridge.