Original scientific paper Stress measurement by using ultrasonic waves is based on acoustoelasticity law, i. e. the relation between stress and wave velocity in engineering materials. Longitudinal critically refracted (LCR) wave is a popular ultrasonic wave in the ultrasonic stress measurement application. The LCR wave is a bulk longitudinal wave that travels within an effective depth underneat...

In the application of guided waves NDT, the selection of exciting frequency is not only related with the setup of sensor, but also with the characteristics of pipe’s structure and material. In this paper, the characteristic of guided waves propagation in pipes that L(0,1) and L(0,2) have a cutoff frequency are respectively discussed, and the calculation formulas of their cutoff frequency are gi...

The ballastless plate girder bridge, classified as a structure type that requires an emergent replacement among domestic railway bridges, generally tends to upgrade ballasted track along with continuous welded rail (CWR). axial forces of the CWR due temperature change need be distributed bridge foundations. Because most existing bridges over 50 years age do not provide any design information, s...

Q690E high strength low alloy (HSLA) steel plays an important role in offshore structures. In addition, underwater local cavity welding (ULCW) technique was widely used to repair important offshore constructions. However, the high cooling rate of ULCW joints results in bad welding quality compared with underwater dry welding (UDW) joints. Q690E high strength low alloy steels were welded by mult...

Abstract We examine the theory of the Hurricane Balls toy. This toy consists of two steel balls, welded into a rigid structure which is sent spinning on a horizontal surface somewhat like a top. Unlike a top, at high frequency the symmetry axis approaches a limiting inclination that is not perpendicular to the surface. We calculate and experimentally verify the limiting inclinations for three t...

In this study, the effect of various welding parameters on the weldability of Mild Steel specimens having dimensions 50mm× 40mm× 6 mm welded by metal arc welding were investigated. The welding current, arc voltage, welding speed, heat input rate are chosen as welding parameters. The depth of penetrations were measured for each specimen after the welding operation on closed butt joint and the ef...

The welding heat input has a great influence on the weldments properties. This paper describes the influence of welding heat input on the weld metal toughness of high-carbon steel surface welded joint. The steel is surfaced with self-shielded wire, with three different heat inputs (6.5; 10.5 and 16 kJ/cm). Total impact energy, as well as crack initiation and crack propagation energies, are esti...

An experiment featuring waterhammer in viscoelastic pipes is presented in which the effects of pipe-wall viscoelasticity on waterhammer pressures are investigated. A large-scale pipeline apparatus made of polyvinyl chloride (PVC) at Deltares, Delft, The Netherlands, has been used to carry out waterhammer experiments. Tests have been conducted in a reservoir-pipeline-valve system consisting of a...

according to flexibility of pneumatic conveying systems with respect to other types of transmission systems, this system has wide application in industry and agriculture processes. one important application of this system is in the loading and unloading tankers and powdery bulk materials such as trucks carrying cement, plaster and sand. conveying efficiency is associated with pressure, which in...