A low concentrated polystyrene (PS) additive to epoxy is used, since it is able to reduce the curing reaction rate but not at the cost of increasing viscosity and decreasing glass transition temperature of the curing epoxy. The modified epoxy is cocured with a compatible thermoplastic interleaf during the vacuum assisted resin transfer molding (VARTM) to toughen the interlaminar of the composit...

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...

Experimental and theoretical analyses are presented that assess true mode II fracture toughness, KIIc, energy, GIIc, associated process zone (FPZ) in anisotropic rocks. The term signifies the type of crack grows a self-planar manner as result shear stresses, thus differentiates it from generic often extends by forming tension-induced kink. We give basis for sinusoidal variation present simplifi...

Vickers indentation fracture can be used to estimate equibiaxial residual stresses (RS) in brittle materials. Previous, conceptually-equal, analytical models were established on the assumptions that (i) the crack be of a semi-circular shape and (ii) that the shape not be affected by RS. A generalized analytical model that accounts for the crack shape and its change is presented. To assess these...

Some cyclically loaded components such as mooring chains can develop fatigue cracks in locations where the shape of part is equivalent to that a curved or bent round bar. Here we consider semi-elliptical crack growing from surface This geometry for example represent chain link segment with located at its inner- outer radius. The be either almond shaped, sickle shaped straight-fronted. Stress in...

We consider the plane elasticity problem of two asymmetrical edge cracks emanating from an elliptical hole in two-dimensional decagonal quasicrystals (QCs) under remotely uniform tensile stress. A complex variation method QCs is developed to solve containing defects. The analytical solutions for stress field and intensity factors near crack tip are expressed by using a conformal mapping techniq...

This is the ®rst in a series of two papers generated from a study on net-section-collapse (NSC) analysis of circumferentially cracked pipes. In this paper (part I), a generalized NSC method is presented to predict the maximum moment of a circumferentially cracked pipe with a variable-depth internal surface crack subject to combined bending and tension (pressure-induced) loads. Two sets of equat...

The luminosity dependence of kinematical and isophotal properties of elliptical galaxies is investigated using numerical simulations of galaxy merging, combined with semi-analytical models of hierarchical structure formation. Mergers of spiral galaxies as the only formation mechanism for elliptical galaxies can neither reproduce the kinematical and photometric properties of very massive ellipti...

In this paper, influence of riveting process parameters, namely, riveting force, sheet thickness, friction coefficient and clearance fit are investigated on residual stress field and fatigue life of single riveted lap joint of AA2024 type. According to the effect of riveting induced residual stresses on fatigue life of riveted lap joint, these parameters are optimized to maximize the residual s...