Showing papers by "Jack R. Vinson published in 2000"

Sandwich Beams with Mid-Plane Asymmetry Subjected to Lateral Loads

Abstract: The equations are presented by which to analyze, design and optimize sandwich beams which involve mid-plane asymmetry. Both classical beam theory and a refined theory involving transverse shear deformation are utilized. Explicit solutions for the beam subjected to a uniform lateral load for the boundary conditions of both ends clamped; both ends simply supported and a cantilevered beam are given. To obtain minimum face weight, the means to select each face thickness and the core depth are given for any given material system. In order to choose the face materials to achieve a minimum weight beam, a factor of merit is defined. Various materials are then compared.

High strain rate effects on mechanical properties of glass/polyester and carbon/aluminum composite materials

Abstract: This experimental research was conducted primarily to obtain mechanical property data of various composite materials under high strain rate loading conditions. Compression tests were conducted using the Split Hopkinson Pressure Bar (SHPB) at strain rates ranging from 100/sec to 2000/sec. The composite material system results included in this paper are for glass/polyester and carbon-aluminum. An aluminum alloy material was also tested to develop the test technique and characterize the equipment. In addition, scanning electron microscope (SEM) photographs were taken of the carbon/aluminum fracture surfaces to examine possible failure modes. The results show that many of the composite material mechanical properties are strain rate dependent. This research provides new data for improved designs of composite material structures.