A skilled welder determines the weld joint penetration from his/her observation of the weld pool surface during the welding process. This paper addresses the characterization of the 3D weld pool surface in gas tungsten arc welding (GTAW), i.e., extracting a set of characteristic parameters from the 3D weld pool surface to determine the backside bead width that measures the degree of weld joint ...

In unrelated marrow transplantation, the benefit of matching class II HLA-DRB1 and DQB1 alleles of the donor and recipient is well documented. Little is known about the clinical relevance of matching for class I HLA-A, B, and C alleles. We used DNA-amplification methods to identify the HLA-A, B, and C alleles of 300 patients and their donors. The incidence of graft failure was correlated with m...

Sharma, Saurabh Weld for Itanium Processor (Under the direction of Dr. Thomas M. Conte) This dissertation extends a WELD for Itanium processors. Emre Özer presented WELD architecture in his Ph.D. thesis. WELD integrates multithreading support into an Itanium processor to hide run-time latency effects that cannot be determined by the compiler. Also, it proposes a hardware technique called operat...

Welding input parameters play a very significant role in determining the quality of a weld joint. The joint quality can be defined in terms of properties such as weld-bead geometry, mechanical properties, and distortion. Generally, all welding processes are used with the aim of obtaining a welded joint with the desired weld-bead parameters, excellent mechanical properties with minimum distortio...

A three-dimensional mathematical model and numerical techniques were developed for simulating a moving gas metal arc welding process. The model is used to calculate the transient distributions of temperature and velocity in the weld pool and the dynamic shape of the weld pool for aluminum alloy 6005-T4. Corresponding experiments were conducted and in good agreement with modeling predictions. Th...

This paper develops a method of welding two thin sheets of poly(vinyl chloride) (PVC) with a heated pin, thus allowing construction of a relationship between the weld temperature and weld strength. Constructing a relationship between weld strength and temperature is necessary for modeling many welding processes, including laser transmission welding. An experimental approach to establishing this...

Significant stress concentrations in welded structures typically arise at crack like defects and at weld toes. The geometry of the weld toe is therefore one of the primary geometrical features that control the fatigue life of welded components. This work is focused on evaluating three non-destructive methods to measure the weld toe radius: Weld Impression Analysis (WIA), Laser Scanning Profilin...

As is well known that sensing and measuring the weld pool surface is very important to design intelligent welding machines which is able to imitate a skilled human welder who can choose suitable welding parameters. Therefore, in this paper, we concentrate the problem of weld pool surface 3D reconstruction, which is a key issue in intelligent welding machines development. Firstly, the framework ...

Characterization of flaws of weld bead is imperative for high-quality welding. Methods of weld bead inspection include radiographic, ultrasonic and vision inspection. However, such methods are costly and time consuming. The proposed sensor is light, low-cost and fast. This paper summarizes our work on weld bead monitoring and defect detection using an electromagnetic sensor. Measurements are ac...

This paper investigates the development of weld zone in Resistance Spot Welding (RSW) which focuses on weld nugget and Heat Affected Zone (HAZ). The effects of four factors namely weld current, weld time, electrode force and hold time were studied using a general 2 factorial design augmented by five centre points. The results of the analysis showed that all selected factors except hold time exh...