Efficient Reanalysis of Locally Modified Structures.
Abstract
A unified efficient formulation for the static, dynamic, and stability reanalysis of locally modified structures is presented. The reanalysis problem is to find the structural responses when some of the element properties are adjusted as a result of design modifications. The reanalysis problem is formulated as a problem of much lower order than the original system. This is achieved by utilizing the linearity property of the structure using the pseudo-load concept, together with the solution of the original system. The modifications to the structure are treated as displacement dependent pseudo-loads of the system. By expressing the modified system response as linear combinations of the response of the original system and a term depending on the pseudo-load, a reduced set of response equations can be obtained. In the static and sinusoidal steady state analyses, this leads to a set of linear algebraic equations. For free vibration and stability analyses, this results in an eigenvalue problem. General modifications involve multiple parameters so that numerical solutions are required. Numerical examples are included. For the special case of a single parameter variation, a simple closed form formulation of the reanalysis problem is provided. Explicit reanalysis formulas are presented for changes in the cross-sectional area of truss members, the stiffness of beams, the thickness of plane stress elements, and lumped springs and masses. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1980
- Accession Number
- ADA119606
Entities
People
- B. P. Wang
- W. D. Pilkey
Organizations
- University of Virginia