Accession Number : ADA305099

Title :   Normal and Radial Impact of Composites with Embedded Penny-Shaped Cracks.

Descriptive Note : Interim rept. 13 Feb 78-12 Feb 79,

Corporate Author : LEHIGH UNIV BETHLEHEM PA INST OF FRACTURE AND SOLID MECHANICS

Personal Author(s) : Sih, G. C. ; Chen, E. P.

PDF Url : ADA305099

Report Date : FEB 1979

Pagination or Media Count : 64

Abstract : 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 time-dependent stresses near the crack border can be described by the dynamic stress intensity factors. Their magnitude depends on time, on the material properties of the composite and on the relative size of the crack compared to the composite local geometry. Results obtained show that, for the same material properties and geometry of the composite the dynamic stress intensity factors for an embedded (penny-shaped) crack reach their peak values within a shorter period of time and with a lower magnitude than the corresponding dynamic stress intensity factors for a through-crack. (AN)

Descriptors :   *STRESS ANALYSIS, *MATRIX MATERIALS, MATHEMATICAL MODELS, FOURIER TRANSFORMATION, TIME DEPENDENCE, DEFORMATION, CRACKS, FIBER REINFORCED COMPOSITES, ELASTIC PROPERTIES, IMPACT STRENGTH, APPROXIMATION(MATHEMATICS), SHEAR STRESSES, AXISYMMETRIC, PARTIAL DIFFERENTIAL EQUATIONS, DYNAMIC LOADS, INTEGRAL EQUATIONS, AXIAL LOADS, RADIAL STRESS, LAPLACE TRANSFORMATION, STRESS CONCENTRATION.

Subject Categories : Laminates and Composite Materials
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE