Accession Number : AD0707505

Title :   INELASTIC ANALYSIS OF A UNIDIRECTIONAL COMPOSITE SUBJECTED TO TRANSVERSE NORMAL LOADING,

Corporate Author : RAND CORP SANTA MONICA CALIF

Personal Author(s) : Adams,Donald F.

Report Date : MAY 1970

Pagination or Media Count : 53

Abstract : This memorandum applies the principles of classical plasticity theory to the very real problem of inelastic behavior of composite materials. To demonstrate the methodology, a specific application--trans-verse normal loading of a unidirectional composite--has been selected for detailed analysis. The behavior of a composite material can be divided into three distinct regimes: (l) LINEAR ELASTIC RESPONSE UP TO THE ELASTIC LIMIT, (2) inelastic behavior beyond the elastic limit and up to the loading at which first failure occurs locally, and (3) SUBSEQUENT CRACK PROPAGATION AND TOTAL COMPOSITE FAILURE. Results indicate that extensive local yielding and redistribution of stresses can occur in a composite with very little indication of such be-havior apparent by observation of the total stress- strain response of the composite alone. Thus, the establishment and interpretation of design criteria and theories of failure should be evaluated in light of these results and their im-plications with respect to such phenomena as fatigue life and fracture behavior. (Author, modified-PL)

Descriptors :   (*COMPOSITE MATERIALS, LOADS(FORCES)), REINFORCING MATERIALS, FILAMENTS, ELASTIC PROPERTIES, PLASTIC PROPERTIES, STRESSES, DUCTILITY, CRACKS, NUMERICAL ANALYSIS, MATHEMATICAL MODELS, REINFORCED PLASTICS, EPOXY RESINS, GLASS TEXTILES, ALUMINUM, BORON

Subject Categories : Laminates and Composite Materials
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE