Structural Shear Joints: Analyses, Properties and Design for Repeat Loading

By George T. Hahn, Kaushik A. Iyer, and Carol A. Rubin

This book describes the mechanical response of butt, lap and doubler joints. The findings apply to shear connections in civil, aerospace, and other mechanical structures subjected to repeated loading. The findings are intended for engineers and NDE practitioners concerned with the design of new, as well as inspection and maintenance of existing shear joints.

Fatigue strengths of the joints are derived using conventional, material S-N data and the joint stress concentration factor. Structural Shear Joints treats the different modes of load transmission: the bearing, clamped, and adhesive modes, joint geometry: fastener spacing and number of fastener rows, and fastener geometry: standard and countersunk heads and self-piercing and interference fasteners. It contains analyses that relate global features with the local conditions that govern contact fatigue damage such as the contact pressures, interface slips and the intensity and locations of stress concentrations. The role of fretting wear is discussed.

The estimates of joint fatigue strength are compared with a selection of fatigue strength measurements for aluminum and steel joints. In many cases, the method offers valid estimates and preliminary designs of joints meeting given fatigue strength requirements. The book incorporates the results of over 150 recent and detailed, 2D and 3D finite element analyses of aluminum and steel connections. It includes handbook-type summaries of the results of the finite element calculations, as well as modeling details such as finite element meshes, material models, boundary conditions and validation proceduresto assist design engineers with computations.

A simplified methodology for modeling joints that contain adhesive is also provided. Useful for all engineers concerned with structural fatigue, the book addresses riveted and bolted joints, aluminum connections for airframes and automotive bodies, and steel connections for machines and bridges. It is a unique reference for instructors and students in advanced design courses.

Basing their text on the results of some 150 two- and three- dimensional finite element analyses of aluminum and steel shear connections, Hahn (mechanical engineering, Vanderbilt U.), Iyer (US Army Research Laboratory), and Rubin (mechanical engineering, Vanderbilt U.) provide a summary of stress analyses of fastener joint geometry, adjacent regions of panels, and important design variables that govern fatigue and fretting in shear connections. Global features such as nominal stress, excess compliance, and fastener load are connected with local conditions that affect fatigue and fretting, including contact pressures, interface slips, residual stresses, and the intensity and location of the stress concentrations. Joints covered include butt joints, lap joints, attachment joints, and doublers. Fasteners looked at are pins, standard head fasteners, countersunk fasteners, self-piercing rivets, and interference fasteners. Bearing, clamped, and adhesive modes of load transmission are all considered, as well as bearing mode with hole expansion. Annotation © 2006 Book News, Inc., Portland, OR