CONTINUUM MODELING AND DYNAMIC ANALYSIS OF LARGE TRUSS STRUCTURES
Abstract
Truss structures such as large space structures consist of a large number of truss members. Full scale finite element analysis which accounts for every member is computationally very expensive. In practice, only the lower modes of vibration are of interest, the truss structure may be effectively represented by a continuum model. In this study, an extended Timoshenko beam model is derived to represent large truss structures where the extensional, flexural and shear deformations are coupled. Procedures for evaluating the equivalent continuum beam stiffnesses based on a substructure of the original system are presented. A higher order beam finite element based on the Timoshenko beam model is developed. Using this model, a number of truss structures are studied for free and forced vibration. Forces in the individual members obtained using the continuum model are compared with the full scale finite element solution applied to the original structure. Experiments are conducted on a scaled down truss model. Strain responses in members of the truss model due to an impact force are measured. Comparison of the experimental results and the Timoshenko beam model is very accurate.
Degree
Ph.D.
Subject Area
Aerospace materials
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