Accession Number : AD0746046

Title :   Research on Energy Absorbing Structures. Part X.

Descriptive Note : Final Scientific rept. 1 Feb 71-1 Feb 72,

Corporate Author : ARA INC WEST COVINA CALIF

Personal Author(s) : Maxelsky,Bernard ; Hewitt,Robert R. ; Lin,T. H. ; Lin,Sheng-Rong

Report Date : FEB 1972

Pagination or Media Count : 101

Abstract : An analytical method for predicting the elastic-plastic bending of rectangular plates with large deflection is studied. The effects of plastic strain and large deflection on plate deformation are shown to be the same as a set of applied external forces on the plate in the classical elastic small deflection theory. For the plate considered, the deflection is increased only slightly by plastic strain; however, the maximum extreme fiber stress is considerably relieved by plastic yielding. A method is developed for a solution of the stress field in a semi-infinite elastic-plastic medium under a generalized plane deformation. The slip field and the build-uup of local plastic strain at the free surface under cyclic loading are calculated. This local plastic strain build-up is used as the criterion for estimating early fatigue damage. Active slip on secondary slip systems is considered during fatigue cycling. (Author)

Descriptors :   (*METAL PLATES, BENDING), (*REINFORCED PLASTICS, NONDESTRUCTIVE TESTING), AIRFRAMES, SHIP PLATES, LOADS(FORCES), DEFLECTION, DEFORMATION, STRAIN(MECHANICS), SHEAR STRESSES, PLASTIC PROPERTIES, NUMERICAL ANALYSIS, FATIGUE(MECHANICS)

Subject Categories : Laminates and Composite Materials
      Structural Engineering and Building Technology
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE