Showing papers by "Jack R. Vinson published in 1975"

Composite materials and their use in structures

Abstract: This book attempts to provide a basic fundamental understanding of the physical and mathematical aspects of the materials system and structures comprised of composite materials. The introduction discusses the nature and scope of composite materials, the strengthening processes used in the manufacture of alloys, and the needs for composite materials. Then various types of fiber-reinforced materials are examined, first by discussing the properties of the component phases. Next, the behavior of dispersion-strengthened and directionally solidified eutectics is considered. An introduction to plate and shell theory is given for isotropic materials, and then the stress--strain relations thus developed are extended to deal with anisotropic materials. The deformation of a fibrous composite is analyzed for plate- and shell-type structures. The strength and fracture of composite materials are discussed in the final chapter. The book is not an encyclopedia of all previous research and solutions. 136 figures, 19 tables, 492 references. (RWR)

The Efficient Design of Adhesive Bonded Joints

Abstract: A concise method of analysis is used to study the numerous parameters influencing the stress distribution within the adhesive of a single lap joint. The formulation includes transverse shear and normal strain deformations. Both isotropic or anisotropic material systems of similar or dissimilar adherends are analysed. Results indicate that the primary Young's modulus of the adherend, the overlap length, and the adhesive's material properties are the parameters most influential in optimizing the design of a single lap joint.

On the Ballistic Impact of Textile Body Armor

Abstract: A mathematical model is developed and methods of analysis are formulated for determining the structural response of textile fabric flat panels subjected to ballistic impact by a dense projectile. A stepwise procedure in time is formulated which is suitable for either desk calculator use or for a digital computer in calculating strains, projectile position, forces, and decelerations as functions of time. Analytical results are compared with experimental data for impact of a .22 caliber fragment simulator impacting 1 ply and 12 ply nylon cloth as well as Kevlar (PRD)-49-IV cloth from 1–24 plies.

Interlaminar stresses in laminated cylindrical shells of composite materials

Abstract: Many existing analysis methods for laminated composite material structural components assume structural integrity between laminae and predict load carrying capabilities considerably higher than those sometimes obtained experimentally. These methods do not include the means to determine accurately the interlaminar shear and normal stresses, which can cause premature structural failure. Methods of analysis are presented herein for a laminated circular cylindrical shell composed of generally orthotropic materials subjected to arbitrary axially symmetric loadings. Elastic shell theory, including transverse shear deformation, is utilized. By treating each lamina individually, in conjunction with imposing stress and displacement boundary conditions between laminae, the governing equations for the individual laminae are combined, yielding the interlaminar shear and normal stresses as explicit dependent variables. A parametric study for a generally othotropic circular cylindrical shell, subjected to a uniform pressure with both clamped and simple supported end boundary conditions is presented. Variables include laminate geometry, fiber orientation, stacking sequence and material properties. The solutions obtained provide insight into the interlaminar stress fields of shells with any number of plies, and provide a baseline for finite element and finite difference solutions for the same problem. A computer program has been formulated to expedite calculations with the analytical solution.