Reanalysis-based optimal design of trusses

This paper presents a structural reanalysis method and its applications in optimal design of trusses. This reanalysis technique is derived primarily o n the basis of a reduced basis formulation, and it has several advantages o ver previous reduced basis methods. In particular, the reduced system is un coupled by using a Gram-Schmidt orthonormalization procedure and an error m easure is introduced to adaptively monitor whether a good approximate solut ion is achieved. The latter aspect makes this reanalysis method suitable fo r use in optimal design problems because the changes in design variables us ually vary during a design process. Discussions are presented on the implem entation of this reanalysis method using both mathematical programming and optimality criteria-based optimization schemes. Finally, several example pr oblems of optimal truss design are used to validate the proposed reanalysis -based design procedure. The presented numerical results indicate that the new reanalysis technique affects very slightly the accuracy of the optimal solutions and it does speed up the design process when the system analysed is large. Copyright (C) 2000 John Wiley & Sons, Ltd.