Accession Number : AD0693654

Title :   VISCOELASTIC BEHAVIOR OF A NONLINEAR FIBER-REINFORCED PLASTIC.

Descriptive Note : Final rept. 1 Jan-31 Dec 68,

Corporate Author : PURDUE UNIV LAFAYETTE IND

Personal Author(s) : Lou,Y. C. ; Schapery,R. A.

Report Date : APR 1969

Pagination or Media Count : 63

Abstract : The nonlinear mechanical properties of a unidirectional, glass fiber-epoxy composite at 164F are characterized by using creep and recovery tests together with a constitutive equation based on a thermodynamic theory. The results show that the composite is linearly elastic for the load range studied, but nonlinear viscoelastic behavior is observed for the other orientations. Guided by the nonlinear constitutive equation, the creep and recovery data are plotted on double-logarithmic paper, and the material properties are found by shifting the data to form a 'master curve' for each fiber orientation. Four principal creep compliances are estimated by using the master curves and tensor transformation relations. Finally, we use the nonlinear equation to predict strain response due to multiple-step loading and unloading. The Appendix contains two abstracts of papers which were completed and published during the period covered by this report. (Author)

Descriptors :   (*REINFORCED PLASTICS, VISCOELASTICITY), (*EPOXY RESINS, REINFORCED PLASTICS), COMPOSITE MATERIALS, MECHANICAL PROPERTIES, GLASS TEXTILES, CREEP

Subject Categories : Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE