One of the methods used to investigate the damaged zone in rock structure is the acoustic emission method. This method is based on receiving the elastic waves that are produced by deformation and cracking of the rock mass around the underground excavation. In this research, a study is conducted on the rock samples by a numerical method to investigate the damaged zone caused by the excavat...

− Comparisons of the acoustic emission signals from the pool and microlayer boiling and water drop evaporation are the aim of the paper. The main relationships, dependences and research results will be presented. The mechanism of acoustic emission generation in liquid boiling and evaporation is discussed. Based on a theoretical analysis, a set of random process characteristics in time and frequ...

A preliminary study of Acoustic Emission during orthopaedic screw fixation was performed using polyurethane foam as the bone-simulating material. Three sets of screws, a Dynamic Hip Screw, a small fragment screw and a large fragment screw were investigated, monitoring acoustic emission activity during the screw tightening. Some specimens were overtightened on purpose to investigate the possibil...

This paper did a radial compression fatigue test on glass fiber winding composite tubes, collects acoustic emission signals on different fatigue damages stages, used time frequency analysis techniques of modern wavelet transform, and analyzed the wave form and frequency characteristics of fatigue damaged acoustic emission signals. Three main frequency bands of acoustic emission signal had been ...

A preliminary study of acoustic emission during orthopaedic screw fixation was performed using polyurethane foam as the bone-simulating material. Three sets of screws, a dynamic hip screw, a small fragment screw and a large fragment screw, were investigated, monitoring acoustic-emission activity during the screw tightening. In some specimens, screws were deliberately overtightened in order to i...

In china, atmospheric storage tanks are not included in the management of special equipment, and therefore they are not required to be inspected compulsorily. There is larger difference between China and developed countries on atmospheric storage tank inspection technique than the other techniques on the inspection of pressure vessels. It is widely believed that the strength worsening and perfo...