STRAIN-SOFTENING AND LARGE-DISPLACEMENT ANALYSIS IN STRUCTURAL PLASTICITY

In the past few years, several computer systems for the nonlinear structural analysis by finite elements have been conceived and implemented. Any type of nonlinearity was considered in a unified computational scheme consisting of a combination of the step by step (incremental) approach and the Newton-Raphson procedure for the solution of the resulting nonlinear system at each loading step. Such a unified approach may be successful from the point of view of system organization and implementation, but to expensive, or even incorrect, for particular types of nonlinearities. This paper considers some elastic-plastic problems in which two major aspects have been discregarded; (1) plasticity confined to a few elements of the structure, and (2) possibility of unloading phenomena. The latter imposes a very severe limitation on the size of the loading step, with obvious computational disadvantages. With these considerations in mind the development of a computer system for structural plasticity analysis problems (or strupl-analysis) is currently in progress. The purpose of the paper is to present the concepts involved in this system and its differences with regard to other existing codes. Particular interest is paid to limit load and stability analysis for various types of material and geometrical nonlinear behaviour of the structure. The calculation scheme is first developed for elastic-perfectly plastic structures and then is extended to structures for which strain hardening, strain softening and large displacement effects need by considered. A numerical example illustrates the application of the system to various types of nonlinearities. (a) (TRRL)

  • Availability:
  • Corporate Authors:

    Pergamon Press, Incorporated

    Headington Hill Hall
    Oxford OX30BW,   England 
  • Authors:
    • Franchi, A
    • Cohn, M Z
  • Publication Date: 1980-5

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 421-427
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00324845
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: Jun 12 1981 12:00AM