The effect of bending on the stresses in adhesive joints

The problem of stress distribution in adhesive joints where two orthotropic plates are bonded through a flexible adhesive layer is analyzed. It is shown that the effect of bending of the adherends on the stresses in the adhesive layer is very significant. The transverse shear deformations of the adherends appear to have little influence on the adhesive layer stresses. The maximum transverse normal stress in the adhesive is shown to be larger than the maximum longitudinal shear stress. The method of solution is applied to several examples of specific joint geometries and material combinations, and is proven to be applicable to other related problems

Stress analysis of adhesive bonded stiffener plates and double joints

The general problem of adhesive bonded stiffener plates and double joints of dissimilar orthotropic adherends with transverse shear deformations are analyzed. Adhesive layers are assumed to be of an isotropic, elastic and relatively flexible material. It is shown that the stress distributions in the adhesive layers are very much dependent on the bending deformations in adherends. Also, it is found that, in the adhesive layer, maximum transverse normal stress is, in many cases, larger than the longitudinal shear stress and that both occur at the edge of the joint. The general method of solution developed is applied to several practical examples

"COMPARISON OF VIBRATION CHARACTERISTICS OF STIFFENED, COMPOSITE SHALLOW CIRCULAR CYLINDRICAL SHELL PANELS"

ABSTRACT The problem of "Free Vibrations Centrally and NonCentrally Stiffened Composite Shallow Cylindrical Shell Panels" are briefly considered and their vibration characteristics are compared, in detail, in terms of their natural frequencies and the corresponding mode shapes. First, the complete set of composite shallow cylindrical shell equations are reduced to a system of first order ordinary differential equations in "state-vector" form. Then, by making use of the "Modified Transfer Matrix Method", the effects of the position and the width of the stiffening shell strip in the natural frequencies and the mode shapes of the panel system are plotted and compared. Some significant results of parametric studies and also the possibility of some kind of hit-and-run type of optimization are presented

Free vibrations of bonded single lap joints in composite, shallow cylindrical shell panels

The problem of free vibrations of bonded single lap joints in composite, shallow circular cylindrical shells or shell panels is investigated. The shallow circular cylindrical shell adherends are considered to be made of dissimilar, orthotropic materials adhesively bonded by an in-between, very thin, yet flexible adhesive layer. In the theoretical formulation, a first-order shear deformation shell theory is employed. The complete set of shallow shell equations, in combination with the adhesive-layer equations, is first reduced to a governing system of first-order ordinary differential equations in the state vector form. Then, the resulting equations are integrated by the modified transfer matrix method (with interpolation polynomials and/or Chebyshev polynomials) and the natural frequencies and the modes of the lap joint system are obtained. It was found that the hard and the soft adhesive-layer elastic constants significantly influence the natural frequencies of the shallow shell bonded lap joint system. Also, the effects of some other important parameters on the natural frequencies and the mode shapes are presented