
Accession Number : ADA180817
Title : Divisor Structure of Finite Element Eigenproblems Arising From Negative and Zero Masses.
Descriptive Note : Technical summary rept.,
Corporate Author : WISCONSIN UNIVMADISON MATHEMATICS RESEARCH CENTER
Personal Author(s) : Malkus,David S. ; Xianjun,Qiu
Report Date : FEB 1987
Pagination or Media Count : 7
Abstract : This document explains why and when the divisor structures of finite element eigenproblems is nonpathological even when negative and/or zero masses result from lumping schemes. The only case of concern is when the stiffness matrix is singular due to rigid body modes, as happens, for example, with single elements. It is found that there are no pathologies if the lumping scheme adequately reproduces the kinetic energy of rigid body motion. Keywords: Degree of precision; Mass matrix; Quadrature.
Descriptors : *MATRICES(MATHEMATICS), KINETIC ENERGY, BODIES, MOTION, RIGIDITY, STIFFNESS, EIGENVECTORS, FINITE ELEMENT ANALYSIS, HEURISTIC METHODS
Subject Categories : Theoretical Mathematics
Distribution Statement : APPROVED FOR PUBLIC RELEASE