Title

Dynamic and thermomechanical response of orbital structures

Date of Completion

January 1997

Keywords

Engineering, Aerospace|Engineering, Mechanical

Degree

Ph.D.

Abstract

The present thesis involves the development of a new analytical and computational methodology to determine the undamped and damped dynamic response of multi-bay orbital truss structures moving in a general co-planar earth orbit under external forces. The nonlinear coupled equations of motion are obtained using the Lagrange's equations of motion. An axially flexible two-body mass system (dumbbell structure) in a coplanar orbit is the building block representing individual elements of the multi-body system. The coupled response of the orbital truss studied includes orbital motion, pitch motion, and structural deformation for various initial conditions and loadings. Further, the structure orbiting the earth in space undergoes cycles of entering into and exiting from the Earth's shadow. Hence, it is exposed to a wide temperature range that can cause thermally induced vibrations, thermal buckling, surface material degradation, thermally induced nutational body motion, and thermal stresses. Thus the model includes the thermomechanical response of the space structure. ^