In the aerospace and aviation sectors, the damage tolerance concept has been applied widely so that the modeling analysis of fatigue crack growth has become more and more significant. Since the process of crack propagation is highly nonlinear and determined by many factors, such as applied stress, plastic zone in the crack tip, length of the crack, etc., it is difficult to build up a general an...

The propagation of cracks in layered glass from low-velocity impact of sharp or spherical tip projectiles is observed using high-speed photography. Tests are also carried out to determine the threshold impact energy for chipping in glass blocks and subsurface crack instability in an edge-supported glass plates. The results identify the median and subsurface radial crack systems as the prime dam...

Details of a unified creep-plasticity theory, based on the concept of an internal time, are presented, and a geometric interpretation of such a theory is given. A' tangent-stiffness' formulation, for the finite-element/boundary-element calculation of weak solutions of the strain-history in the structure, is presented. An implicit algorithm of generalized mid-point radial mapping for computing t...

Al 2024-T351 has been modeled using a kernel-based multi-variate Gaussian Process approach. The Gaussian Process model projects fatigue affecting input variables to output crack growth by probabilistically inferring the underlying nonlinear relationship between input and output. The Gaussian Process approach not only explicitly models the uncertainty due to scatter in material microstructure pa...

Experiments involving vibrating pastes before drying were performed for the purposes of controlling the crack patterns that appear in the drying process. These experiments revealed a transition in the direction of lamellar cracks from perpendicular to parallel when compared with the direction of the initial external vibration as the solid volume fraction of the paste is decreased. This result s...

The role of elastic mismatch in determining critical conditions for indentation fracture in brittle coatings on substrates of unlike modulus was investigated. A model transparent trilayer system, consisting of a glass coating layer bonded to a thick substrate of different glass or polymer by a thin layer of epoxy adhesive, facilitated in situ observations of crack initiation and propagation. A ...

Consider a three-dimensional homogeneous isotropic elastic solid containing a flat pressurized crack, fi. The problem of finding the resulting stress distribution can be reduced to a hypersingular integral equation over Q for the crack-opening displacement. Here, this equation is transformed into a similar equation over a circular region D, using a conformal mapping between Q and D. This new eq...

Considering backlash, time-varying mesh stiffness and radial clearance of bearing, nonlinear dynamic model of gear bearing flexible shaft system is established taking into account breathing crack in shaft and tooth wear. Nonlinear dynamic equations are solved by Runge-Kutta method. Effect of backlash, crack in shaft and tooth wear faults on the nonlinear dynamic behavior of gear-shaft-bearing s...

Failure behavior of composite materials in general and particulate composites in particular is intimately linked to interactions between a matrix crack and a second phase inclusion. In this work, surface deformations are optically mapped in the vicinity of a crack–inclusion pair using moiré interferometry. Edge cracked epoxy beams, each with a symmetrically positioned cylindrical glass inclusio...