In this paper, the adhesive stresses in unbalanced bonded single-strap butt joints are
theoretically studied. Mathematical difficulties in the analysis of high order
differential equations were solved and closed-form solutions for both the adhesive peel
and shear stresses have been successfully developed. In the proposed solutions the
adherends and doublers can be different in material and thickness. Peak stresses are
located at the bonded overlap edges, especially at the inner edges. In addition,
two-dimensional geometrically nonlinear finite element analyses were carried out to
study the adhesive stresses in two different bonded butt joints. One was a
special butt joint case with the adherends and doubler of identical material
and thickness, and the other was a general butt joint case with different
adherends and doubler. Good agreement in the adhesive stresses between
the closed-form solutions and finite element results has been achieved. The
single-strap butt joint actually consists of two single-lap joints; thus, the
adhesive stress solutions can be further applied to unbalanced single-lap
joints.
Keywords
adhesive stress, closed-form solution, single-strap butt
joint, finite element analysis
Structures and Materials Performance
Laboratory
Institute for Aerospace Research
National Research Council Canada
1200 Montreal Road, M-3
Ottawa, Ontario K1A 0R6
Canada
