hydraulic fracturing (hf), as a stimulation technique in petroleum engineering, has made possible the oil production from reservoirs with very low permeability. the combination of horizontal drilling and multiple hf with various perforation angles has been widely used to stimulate oil reservoirs for economical productions. despite the wide use of hf, there are still ambiguous aspects that requi...

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 ...

When a femtosecond laser pulse is focused inside a LiF single crystal, four cracks are generated in the <100> directions from the photoexcited region. The time-resolved observation have elucidated that the tensile stress in the laser induced stress wave induces the generation and propagation of the cracks. In this study, to investigate the possibility of control of laser induced cracks inside s...

using cold working fastener holes is a simple life enhancement procedure that strengthens metallic components by retarding crack growth around a hole. in the present paper, the residual stress field that is induced by the hole expansion process is obtained based on different material models namely elastic perfect plastic, isotropic hardening and kinematic hardening using three-dimensional finit...

Smart film crack monitoring method, which can be used for detecting initiation, length, width, shape, location, and propagation of cracks on real bridges, is proposed. Firstly, the fabrication of the smart film is developed. Then the feasibility of the method is analyzed and verified by the mechanical sensing character of the smart film under the two conditions of normal strain and crack initia...

The evaluation of stress intensity factors (SIFs) for cracks in mechanically fastened joints is one of the central issues in a damage tolerance analysis. Accurate stress intensity solutions may be difficult to determine due to geometric complexity along with variations in fastener load transfer and fastener interference and material thickness because of corrosion. Detailed finite element models...

Using cold working fastener holes is a simple life enhancement procedure that strengthens metallic components by retarding crack growth around a hole. In the present paper, the residual stress field that is induced by the hole expansion process is obtained based on different material models namely elastic perfect plastic, isotropic hardening and kinematic hardening using three-dimensional finit...

Solar cell is known as a sustainable and environment friendly source of energy in nature. It converts sunlight directly into electricity with zero emission and also without side-effects on the environment. But, solar cells have optical and mechanical defects which include the type of micro crack, the size of crack, and the noise from electrical or electromechanical interference during the image...

Backscatter of time-harmonic longitudinal waves from a surface-breaking crack is investigated in the highfrequency range. It is assumed that the distance of the transducer to the crack is large as compared to the crack depth, and that the incident rays are normal to the crack edge. The crack length is assumed much greater than its depth. A two-dimensional model for the transducer is considered....