A method is developed for the dynamic stress analysis of a layered composite containing an embedded penny-shaped crack and subjected to normal and radial impact. The material properties of the layers are chosen such that the crack lies in a layer of matrix material while the surrounding material possesses the average elastic properties of a two-phase medium consisting of a large number of fibers embedded in the matrix. Quantitatively, the ...
The dynamic response of unidirectional composites under off-axis (angle loading) impact is analyzed by assuming that the composite contains an initial flaw in the matrix material. The analytical method utilizes Fourier transform for the space variable and Laplace transform for the time variable. The off-axis impact is separated into two parts; one being symmetric and the other skew-symmetric with reference to the crack plane. Transient boundary conditions of normal and ...
Finite element procedures are used to solve two- and three-dimensional problems of cracks in elastic bodies. The two-dimensional, plane strain analysis is concerned with the effect of a crack approaching a free edge at right angles. The strain energy density fracture criterion is used to determine the direction of fracture for various distances from the crack tip to thr free edge. These results provide a possible mechanism for the creation ...
The concept of fracture mechanics is introduced to characterize the toughness of fiber-reinforced composites which should be distinguished from tensile strength. Composites with well-aligned fibers are more susceptible to crack propagation parallel than perpendicular to the fibers and can be analyzed with a reasonable degree of accuracy by using the existing Kc or Sc-theory in fracture mechanics. The Kc-theory is used primarily in laboratory testing where the load is aligned ...
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