The bonding strength between dissimilar materials in composites is often relatively weak. Interface debonding and cracking are of common occurrence. As an e€ ective method to minimize such failures, ® bre stitching is used to enhance the bonding strength when joining layers in polymer composites. With the presence of the reinforcing ® bre, the overall elastic response for each component of the ...

Effects of matrix cracks and the attendant interface debonding and sliding on both the longitudinal and the transverse thermal diffusivities of a unidirectional Nicalon/MAS composite are investigated. The diffusivity measurements are made in situ during tensile testing using a phase-sensitive photothermal technique. The contribution to the longitudinal thermal resistance from each of the cracks...

The present paper is concerned with the effective numerical implementation of the two-dimensional dual boundary element method, for linear elastic crack problems. The dual equations of the method are the displacement and the traction boundary integral equations. When the displacement equation is applied on one of the crack surfaces and the traction equation on the other, general mixed-mode crac...

A model has been developed to predict crack opening and closing behavior for propagating fatigue cracks which undergo significant sliding displacements at crack flanks. Crack surfaces were described statistically by assuming a random distribution of asperity heights and a mean density of asperities and asperity radii. The propagating crack was subdivided into strips, and each strip was treated ...

a new approach for analyzing cracked problems in 2d orthotropic materials using the well-known element free galerkin method and orthotropic enrichment functions is proposed. the element free galerkin method is a meshfree method which enables discontinuous problems to be modeled efficiently. in this study, element free galerkin is extrinsically enriched by the recently developed crack-tip orthot...

Edge-notched eccentrically compressed fracture specimens made of aggregate of reduced size are loaded in standard creep test frames. Measurements of the time rate of crack mouth opening in notched concrete specimens subjected to constant load of almost one month duration are reported and analyzed. To reveal the size effect, geometrically similar specimens of four sizes in the ratio I :2:4:8 are...

An experimental investigation dealing with failure characterization of 63/37 soldercopper interfaces is presented. The method of moird interferometry is used for mapping elasto-plastic deformations in bimaterials subjected to predominantly tensile loading. A method for quantifying the fracture parameter--the J-integral--using full-field measurement of crack opening displacements has been develo...

An axi{symmetric problem for a penny{shaped crack bridged by bres is considered. The study is reduced to the analysis of a hy-persingular integral equation with respect to the relative crack{face separation over a circular domain occupied by crack. The special case of a large crack subjected to Mode{I loading is examined. A matched asymptotic expansions technique is used in order to estimate th...

A new algorithm is described which extends the material point method (MPM) to allow explicit cracks within the model material. Conventional MPM enforces velocity and displacement continuity through its background grid. This approach is incompatible with cracks which are displacement and velocity discontinuities. By allowing multiple velocity fields at special nodes near cracks, the new method (...