In this study, the damage fields near the crack tip in edge-cracked sheet specimens subjected to a constant strain rate of 0.05 min were investigated using real-time radiographic techniques. During the tests, Lockheed-Martin Advanced Technology Center’s high-energy real-time x-ray system (HERTIS) was used to monitor damage initiation and evolution processes near the crack tip. The experimental ...

Abstract. The existence of crack evolutions based on critical points of the energy functional is proved, in the case of a cohesive zone model with prescribed crack path. It turns out that evolutions of this type satisfy a maximum stress criterion for the crack initiation. With an explicit example, it is shown that evolutions based on the absolute minimization of the energy functional do not enj...

The present paper adopts a Bayesian approach to update some of the parameters of the probability distributions governing the reliability assessment of maintained floating structures. It is based on a time dependent fatigue reliability formulation presented earlier but the description of the time to crack initiation, crack growth law and probability of crack detection are updated using the infor...

In this paper, the effect of interference fit on fatigue life of holed plate of mechanical joints was investigated experimentally. Fatigue tests were carried out on the holed specimens of Al-alloy 7075-T6 alloy. The interference fit process consists of force fitting a fastener into the hole with a negative clearance (diameter of the fastener is larger than of the hole) that produces beneficial ...

Excavation unloading significantly contributes to rock slope failure in an open-pit mine. At present, there is no relevant theoretical study on the mechanism of under excavation unloading. Therefore, this study, based theory fracture mechanics, expression stress intensity factor at crack tip mass vertical distance, h, from top derived, calculation method initiation angle given, ultimate safe he...

The growth of a single cylindrical hole ahead of a blunt crack tip was studied using large deformation finite element analysis in three-point bend specimens with different precrack depth. The effect of small second phase particles was taken into account by incorporating Gurson’s constitutive equation. The effects of strain hardening and the initial distance from the hole to the crack tip were a...

In present paper, using Acoustic Emission (AE) as a ultrasonic technique, Welding crack has been investigated on the HG70 steel used by truck crane during three-point bending test was carried out. The study shows that the activity of AE increases greatly during the welding crack initiates and propagates, and the distributing range of AE characteristic parameters can be fixed. AE signals of weld...

To explore the failure mechanism of rock with holes and fissures, uniaxial compression tests sandstone samples combined double hole fissure defects were carried out using Particle Flow Code 2D (PFC2D) numerical simulation software. The behaviour mechanical properties at different angles analysed, evolution results stress field crack propagation studied. show that a decrease in angle, initiation...