Accession Number : AD0643087

Title :   ON THE ENERGY CONCEPTS IN THE THEORY OF ELASTIC STABILITY.

Descriptive Note : Technical rept.,

Corporate Author : CALIFORNIA UNIV SAN DIEGO LA JOLLA DEPT OF THE AEROSPACE AND MECHANICAL ENGINEERING SCIENCES

Personal Author(s) : Nemat-Nasser,S. ; Roorda,J.

Report Date : NOV 1966

Pagination or Media Count : 28

Abstract : The problem of local stability of structural systems subjected to conservative and nonconservative external forces is examined. It is shown that, contrary to the usual assumption and in contrast to the case of conservative loading, if linearized analysis is used for local stability investigation of nonconservative systems, then the existence of simple harmonic vibrations of constant amplitudes does not necessarily imply stability. In this case, the local stability of the equilibrium can only be decided upon by a nonlinear analysis. Moreover, it is shown that, for such systems, the linearized analysis yields the true 'critical' force only if all the dissipative forces are included directly in the analysis. Finally, certain thermodynamic implications of these observations are pointed out. (Author)

Descriptors :   (*STRUCTURES, STABILITY), FORCE(MECHANICS), THEORY, STRUCTURAL PROPERTIES, ELASTIC PROPERTIES, ENTROPY, LOADS(FORCES)

Subject Categories : Structural Engineering and Building Technology
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE