Accession Number : AD0685712

Title :   EXPERIMENTS ON DISPERSIVE PULSE PROPAGATION IN LAMINATED COMPOSITES AND COMPARISON WITH THEORY.

Descriptive Note : Technical rept. Jul 68-31 Jan 69,

Corporate Author : AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS

Personal Author(s) : Whittier,James S. ; Peck,Jerry C.

Report Date : 14 FEB 1969

Pagination or Media Count : 35

Abstract : Transient stress-wave experiments on laminated composites are described, and the results are compared with theoretical predictions. The composites are laminated from alternating layers of high- and low-modulus material, which cause a high degree of geometric dispersion of waves propagating in the composite. Experiments were conducted in which waves propagated parallel to the laminations. Flat plates were subjected to spatially uniform pressure with step-function time dependence induced by a gasdynamic shock wave. Under this loading, the central portion of the specimen initially responds as if it were laterally unbounded. The average velocity over a 3/8-in.-diam. area of the backface of the plate was measured with a capacitance gauge. The results are in good agreement with theoretical predictions made with a long-time asymptotic approximation called the head-of-the-pulse approximation. The principal conclusions are based on the agreement between experiment and theory. The experimental technique is demonstrably effective, and the theoretical predictions based on the head-of-the-pulse approximation are qualitatively correct and of reasonable quantitative accuracy. (Author)

Descriptors :   (*COMPOSITE MATERIALS, SHOCK WAVES), LAMINATES, PROPAGATION, NUMERICAL ANALYSIS

Subject Categories : Laminates and Composite Materials
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE