The failure stress under four-point bending cannot be considered as an intrinsic material property because of the well-known size effect increasing maximum flexural with decreasing specimen size. In this work, tests are analyzed coupled criterion for different sample sizes. only tends towards tensile strength provided height is large enough compared to characteristic length. that case, mainly d...

Information fit indexes such as Akaike Information Criterion, Consistent Akaike Information Criterion, Bayesian Information Criterion, and the expected cross validation index can be valuable in assessing the relative fit of structural equation models that differ regarding restrictiveness. In cases in which models without mean restrictions (i.e., saturated mean structure) are compared to models ...

Abstract This paper considers optimum plans for failure-step stress partially accelerated life tests with two stress levels under type-II censoring assuming Weibull distribution as a lifetime model. The optimum test plans determine the optimum proportion of test units failing at each stress according to a certain optimality criterion. The D-optimality criterion is considered. Some numerical ill...

Strength properties of most sedimentary and metamorphic rocks are known to vary with direction. Knowledge this so-called rock anisotropy is utmost importance for reliability analysis engineering design. The purpose paper twofold. First, we propose a formulation the Hoek–Brown (HB) failure criterion, which calculates strength using non-uniform scaling stress tensor. We use two factors, CN CS, li...

There are prevailing concerns with the critical dimensions when conventional theories break down. Here we find that the Griffith criterion remains valid for cracks down to 10 nm but overestimates the strength of shorter cracks. We observe the preferred crack extension along the zigzag edge in graphene, and explain this phenomenon by local strength-based failure rather than energy-based Griffith...

During the years of operation, underground pipelines deteriorate because aging, wear, damage, and destruction. A comprehensive inspection main pipeline revealed various defects on a certain route section. To identify remaining operation life pipeline, number hydraulic tensile strength tests were performed using cyclic loading method. The authors propose to calculate minimum allowable wall thick...