OBJECTIVE To examine relationships between parenting behaviors, parent-child relationship, and moderating effects of age on youth substance use among a community sample of African-American mothers who use crack cocaine and their children (12-17 years). METHODS Maternal-child dyads (n = 208) were recruited through street outreach and snowball sampling and completed interviews about substance u...

in this paper, the crack detection and depth ratio estimation method are presented in beamlikestructures using elman networks. for this purpose, by using the frequencies of modes asinput, crack depth ratio of each element was detected as output. performance of the proposedmethod was evaluated by using three numerical scenarios of crack for fixed-simply supportedbeam consisting of a single crack...

Since meshfree particle methods have advantages on simulating the problems involving extremely large deformations, fractures etc., they become attractive options to be used in the hierarchical multiscale modeling to approximate a large number of atoms. We propose a nanoscale meshfree particle method with the implementation of the quasicontinuum technique in this paper. The intrinsic properties ...

Abstract Polycrystalline nickel‐based superalloys experience accelerated intergranular crack growth when exposed to dwell times in oxygen‐rich environments and a combination of high temperature tensile mechanical loading. Increasing rates are observed for increasing amounts environmental oxygen certain concentration range, while below above that range remain approximately constant. A fully coup...

In this paper, the use of a cohesive-zone approach to model the mode-I fracture of adhesive joints made from a polymer-matrix composite is demonstrated. Cohesive-zone parameters were obtained by matching numerical results to experimental observations. It is shown that there is a distinction between the characteristic strength of the interface associated with the toughness, and the intrinsic coh...

Crack extensions in uncharged and hydrogen-charged side-grooved A(T) specimens of conventionally forged 21-6-9 austenitic stainless steels are simulated using the cohesive zone modeling approach. Two-dimensional plane strain finite element analyses with fixed parameters first conducted to fit experimental load-displacement curves. Similar varying as functions crack extension then load-crack ext...

The aim of this paper is to simulate the propagation linear elastic crack in 3D structures using latest innovation developed Ansys software, which Separating Morphing and Adaptive Remeshing Technology (SMART), order enable automatic remeshing during a simulation fracture behaviors. ANSYS Mechanical APDL 19.2 (Ansys, Inc., Canonsburg, PA, USA), used by employing special mechanism ANSYS, smart gr...

A phase-field model based on a modified form of the regularized formulation Griffith’s fracture theory is presented to investigate intergranular and transgranular crack propagations in polycrystalline brittle materials. Grains grain boundaries are incorporated initiation propagation for growth, which elastic anisotropy varies orientation angle, boundary energy related misorientation angle adjac...

Brittle oxide glasses can easily break into fragments because of crack branching during fracture. The fundamental mechanism underlying this common phenomenon remains controversial. In study, using atomic-scale simulations with three independent force fields, we directly observe in silica glass. critical speed at which the branches increases far field loading. atomic revealed that brittle glass ...