OBJECT-ORIENTED APPROACH TO MODELING AND ANALYSIS OF TRUSS STRUCTURES

Object-oriented structural and geometric analysis methods for truss st ructures are proposed. The methods are based on the iterative relaxati on of nodal unbalanced forces by moving the nodes. The entities appear ed in truss analysis are modeled as classes, and their class hierarchy is established. The knowledge about a truss node, a truss member, a m aterial, and a sectional shape of the member are extracted and constru cted as a knowledge base in an object-oriented manner. The object-orie nted structural analysis is found to be valid for material and geometr ic nonlinearities, and the object-oriented geometric analysis where a kinematic problem is converted into a problem for a force equilibrium at the nodes is also found to be effective for determining the geometr y of variable geometry trusses. The whole system is written in an obje ct-oriented language, Smalltalk, and several results on structural and geometric analysis are presented. The speed of the computation is dis cussed along with the size of the structures and the over-relaxation f actor. The extension of the knowledge base is also discussed.