Accession Number:

ADA162319

Title:

Simplified Nonlinear Analysis of Large Space-Trusses and Space-Frames, Using Explicitly Derived Tangent Stiffnesses and Accounting for Local Buckling.

Descriptive Note:

Final rept. 1 May 83-30 Apr 85,

Corporate Author:

GEORGIA INST OF TECH ATLANTA CENTER FOR THE ADVANCEMENT OF COMPUTATIONAL MECHANICS

Personal Author(s):

Report Date:

1985-08-01

Pagination or Media Count:

193.0

Abstract:

Simplified finite element methods for finite deformation, post-buckling analysis of large space trusses and space frames are presented. Arbitrarily large rigid translations and rigid rotations of each member are accounted for. Each 3-D truss member is assumed to withstand an axial force, while each 3-D frame member is assumed to withstand two bending moments, a twisting moment, and transverse and axial forces at each node. The influence of local member buckling on global instability is systematically examined. For both 3-D truss and frame members, explicit tangent stiffness matrices are derived. By explicit it is meant that no element-wise basis functions are assumed and that no element-wise numerical integrations are involved. These explicit tangent stiffness matrices are very simply evaluated at any point in the load deformation history of a space truss, or space frame, undergoing large deformations, as well as in the post-buckled region of behavior of these structures. An arc-length method is implemented to trace the post-buckling behavior of these large space structures. A large number of examples are included to 1 bring out the economy as well as accuracy of the simplified method developed 2 indicate the effectiveness of the present method in creating reduced-order models of large space structures and 3 delineate the process whereby the overall behavior of the structure can be vastly improved by controlling the deformation of individual members through active or passive mechanisms. Keywords Reduced order model Simplified nonlinear analysis Finite deformations Finite rotations Semi-tangential rotations Exact tangent stiffness matrix LSS Large Space Structure control Arc-length method.

Subject Categories:

  • Mechanics
  • Unmanned Spacecraft

Distribution Statement:

APPROVED FOR PUBLIC RELEASE