Underwater wet welding is one of the most common repair measures for corroded offshore steel structures. Few studies have been carried out systematically concerned with mechanical properties of such welds, thus current design provisions rely heavily on limited experimental data on welds made underwater and design properties for corresponding welds made in air. This paper presents a series of ex...

This paper describes the development of a probabilistic methodology for fracture-mechanics analysis of weld cracks in a center-cracked tension (CCT) specimen. It involves elastic±plastic analyses to predict J-integral, statistical models of uncertainties in loads and material properties, and standard computational methods of structural reliability theory for probabilistic analysis. Eighty-one d...

In a shell and tube heat exchanger, the failure of tube-to-tubesheet welds results in high-pressure water jet which erodes the refractory in front of the tubesheet. Finite element method was employed to simulate the welding process and post weld heat treatment (PWHT) to find the factors affecting the failure in tube-to-tubesheet weldments. Residual stresses in two different geometries of tube-t...

The present paper describes fuzzy logic simulation of shielded metal arc welding (SMAW) process to predict the Quality of weld joint. It describe the quality of weld joint & effect of welding current, voltage and welding speed on tensile strength of shielded metal arc pipe welded mild steel joints. An ERW Mild steel pipe I S 1239 of 6 mm thickness and 150 mm diameter were used as the base mater...

Friction stir welding (FSW) is a solid-state jointing technology, in which the butted plates are heated, plasticized and jointed locally by the plunged probe and shoulder moving along the joint line. The residual stresses due to the thermomechanical performance of the material and the constraint of the welded plates by the xture are one of main concerns for this process. A prediction of the cla...

An LPG tank fabncated by a major manufacturer in the late 1940s with rolled skid plate, commonly used in steel floor construction, burst catastrophcally under direct sunlight. The rupture caused extensive property damage and fatal injury. Metallurgxal analysis revealed that at time of fabrication the full penetration longitudinal seam weld of the tank had been torch cut and then reconnected wit...

Gas metal arc welding has been generally accepted as the preferred joining technique due to its advantages in high production and automated welding applications. Separate control of arc energy and arc force is an essential way to improve the welding quality and to obtain the projected metal transfer mode. One of the most eVective methods for obtaining separate control is to exert an additional ...

Infrared Thermography is an advanced Non Destructive Evaluation technique based on the detection of infrared radiation. It is best suited for online weld monitoring to produce defect free welds. The most important step involved in online weld monitoring is to develop an automated algorithm for weld defect detection and quantification. Incomplete Penetration occurs when penetration of the weld m...

Welding quality control is an important parameter for safe operation of oil and gas pipes, especially for high-strength steel pipes. Size control of welding defect is a bottleneck problem for current pipe construction. As a key part of construction procedure for butt-welding of pipes, pore defects in girth weld is difficult to ignore. A three-dimensional non-linear finite element numerical mode...

This thesis presents the Order of Magnitude Scaling methodology and uses it to determine the con guration and dominant forces in the weld pool during high productivity arc welding. This methodology was developed to consistently address problems for which experimental and mathematical treatment is di cult, yet the governing equations and some general characteristics are known. The results genera...