Linearly Increasing Stress Tests conducted in 30 C aerated distilled water using as-quenched 4340 and 3.5NiCrMoV turbine rotor steels indicated that stress corrosion cracking occurred at all applied stress rates for 4340 steel, whilst only at applied stress rates less than or equal to 0.002 MPa s 1 for the turbine rotor steel. The crack velocity increased with increasing applied stress rate for...

Fracture networks dominate the permeability of crystalline geothermal reservoir rocks. Insitu stress conditions have a significant impact on the flow, transport and exchange characteristics of fracture networks. Here a geomechanical model is presented which describes fracture closure under effective stress and the change in parameters such as storage, permeability, porosity and aperture. The mo...

The fracture mechanics examines the development and expansion of cracks in solids and how they affect the deformation of materials. The stress intensity factors at the tip of the crack and the critical stress intensity factors or fracture toughness of materials are considered in the relevant criteria. There are three main modes of applying forces to a crack including the tensile mode, shear mod...

A 24-year-old man presented with a stress fracture over his left tibia following an infantry training 6 years ago. X-rays of his left tibia revealed a stress fracture and bone scan showed marked tracer uptake at the fracture. He was treated conservatively but his pain persisted since then. Five years later, X-rays and histological examination confirmed the diagnosis of osteoid osteoma. The stre...

Materials fail by the nucleation and propagation of a crack, the critical condition of which is quantitatively described by fracture mechanics that uses an intensity of singular stress field characteristically formed near the crack-tip. However, the continuum assumption basing fracture mechanics obscures the prediction of failure of materials at the nanoscale due to discreteness of atoms. Here,...

In pressure sensitive reservoirs, interaction effects among the porous media flow field, the fracture field and the stress field can cause some specific flow characteristics entirely different from those in conventional reservoirs. Dynamic fracture behavior is one of them, which generates a change in the value of fracture aperture and even a variation in the anisotropy of permeability. In this ...

Stress fracture of the femoral neck is rare and often initially missed. A high index of clinical suspicion is required in athletes presenting with a history of insidious onset, exertional groin pain and pain at the extremes of hip motion on examination. Regular review is recommended to prevent progression of the stress fracture to a displaced fracture, as this significantly worsens long term ou...

OBJECTIVES The objective of the present study was to evaluate a prefabricated intraradicular threaded pure titanium post, designed and developed at the São José dos Campos School of Dentistry - UNESP, Brazil. This new post was designed to minimize stresses observed with prefabricated post systems and to improve cost-benefits. MATERIAL AND METHODS Fracture resistance testing of the post/core/r...

A prospective study was undertaken on 50 acute, consecutive fractures of the radial head. Clinical examination and stress testing were performed on each patient. A valgus stress radiograph, in conjunction with clinical stress testing, was used to assess competence of the medial elbow ligaments. Axial stability of the radius was determined by the axial stress test. Eleven patients (22%) sustaine...