Out-plane Shear Research Articles

Shear Buckling Analysis on Laminated Composite Plates with Out-of-Plane Shear Deformation.

The shear buckling analysis on laminated composite plates considering the out-plane shear deformation is presented using the pb-2 Ritz functions which consist of the product of a basic function and a two dimensional polynomial function. It is shown that the convergence of solutions for the buckling load of laminated composite plates is good as the number of polynomials is more than 30. Numerical results under shear load are obtained for cross-ply and angle-ply laminated composite plates, and the difference between the buckling factors in positive and negative shear load are discussed. The effects of material properties, plate aspect ratio, number of layers and lamination angle on buckling factors are investigated under simple supported and clamped edges. It is shown that the presented method considering the out of plane shear deformation can be widely used to analyze buckling behavior of composite plates with general boundary conditions.

面外せん断変形を考慮した複合材料積層板の二軸圧縮座屈解析

The buckling analysis of laminated composite plates compressed in two perpendicular directions is presented by using the pb-2 Ritz functions, which consist of the product of a basic function and a two dimensional polynomial function. The out-plane shear deformation is also taken into consideration in this analysis. It is shown that the convergence of solutions for the buckling load is good when the number of polynomials is more than 20. Numerical results are obtained for cross-ply and angle-ply laminated composite plates compressed in two perpendicular directions. The effects of material properties, plate aspect ratio, number of layers and lamination angle on buckling load are also investigated under simple supported, clamped edges and combined edge conditions. It is shown that the presented method considering the out-of-plane shear deformation can be widely used to analyze the buckling behavior of composite plates with general boundary conditions.

A Comparative Study of the Fracture Properties of Five Grasses

1. The mechanical properties of plants constrain herbivory. Fracture properties of five species of grass were measured using tests which fractured leaves, pseudostems and whole tillers in tension (mode 1) and in out of plane shear (mode III). Force (F), energy to fracture (U) and energy per unit area (U/A) were calculated from force-displacement curves. 2. Fracture properties varied widely, depending on species, morphological unit, sclerenchyma or fibre content, and whether the grass was fractured in tension or in shear. 3. Older leaves contain more sclerenchyma than younger leaves, resulting in higher F, U and U/A. 4. Pseudostem is tougher and stronger than leaf whether fractured in shear or in tension, owing to its complex structure and capacity for plastic deformation, larger cross sectional area, and higher fibre content. 5. Entire tillers tested under tension required much less energy to fracture than leaf or pseudostem. 6. Fracture occurs at a zone of weakness at the intercalary meristem and it is argued that this is an evolutionary advantage to grass species which are commonly grazed. The fibre content of grasses increases the difficulty both of harvest and digestion by herbivores

Stress-based elastodynamic discrete laminated plate theory

A static laminated plate theory based on an assumed piecewise linear through-the-thickness in-plane stress distribution has been extended to include inertia effects. Based on this in-plane stress distribution assumption, outof-plane shear and normal stress component distributions were derived from the three-dimensional equations of motion, resulting in six nonzero stress components. Hamilton's variational principle was used to derive the plate equations of motion, the plate constitutive relationships, and the interface continuity equations. The governing equations were written in a form that is self-adjoint with respect to the convolution bilinear mapping. The resulting system of equations for a single lamina consists of 25 field equations in terms of 9 weighted displacement field variables, 10 stress and moment resultant field variables, and 6 out-of-plane shear and normal stress boundary field variables. For the laminated system, the mixed formulation enforces both traction and displacement continuity at lamina interfaces as it satisfies layer equilibrium. A finite element formulation based on a specialized form of the governing functional was developed. The method is illustrated with results of a free vibration analysis of sandwich and homogeneous plates for which exact solutions are available.

The solution of a certain dual cosine series relation occurring in orthotropic fracture

This paper determines the solution of a certain dual cosine series relation that arises in the problem of the out of plane shear of a rectangular orthotropic block with an edge crack. Once the solution to the dual series is known, we solve the edge crack problem exactly. We note that for the case of a constant shear the stress intensity reduces to a simple form and numerical results are given.

Cracks at the edge of an elliptic hole in out of plane shear

In this paper integral transform techniques are used to find the mode III stress intensity factors for cracks at the edge of an elliptic hole in an infinite elastic solid.

Cracks of unequal length at the edge of an elliptic hole in out of plane shear

Integral transforms are used to find mode III stress intensity factors for two unequal length cracks at the edge of an elliptic hole in an infinite elastic solid.

Out of plane shear of a cracked rectangular orthotropic block

The problem under consideration is the out of plane shear of a cracked rectangular orthotropic block. The exact solution is obtained by stating the problem in terms of a triple trigonometric series relation, which in turn can be shown to be equivalent to a singular integral equation whose solution is known. For the case of constant shear, the solution simplifies greatly and numerical results are given.

A notched bimaterial body under out of plane shear

A notched bimaterial body under out of plane shear