As the control valve of the propulsion system engine, the electromagnetic valve play an important role in attitude and orbit control for spacecraft. While the leak of the electromagnetic valve has always been the main cause of the failure of the propulsion system. Due to the shell’s complex structure as well as many seam weld on it, the normal NDT is unfit to check out some small cracks and mic...

Defect in welded structures is a matter of serious concern. The current practice involves interpretation by inspectors and experts, of radiographs after the weld is completed which is time consuming. With greater emphasis on automation during manufacturing process, automated NDT has gained prominence. One of the Non Destructive Evaluation (NDE) techniques that is being increasingly applied for ...

Abstract Welding round bars of large diameters in a rotational laser beam welding process corresponds with weld pool bulging and the risk defects. Power modulation is promising approach for bulge reduction keyhole stabilisation to achieve superior quality. The following investigations are about specific effects power diameter 30 mm. speed 0.95 m/min argon used as shielding gas. Triangle shaped ...

ion of Models of Stress Corrosion Cracking of Drip Shield and Waste Package Outer Barrier and Hydrogen Induced Corrosion of Drip Shield TABLE OF CONTENTS Page 1. PU R P O SE ............................................................................................................................... 8 2. QUALITY ASSURANCE .............................................. 8 3. COMPUTER SOFTWARE AN...

The primary NDT method for welding defects is the image-based detection. Currently, best performance detection based on transformer model. However, with its high accuracy, it has many limitations, such as large model parameters, data sample requirements, and expensive computer resources. This a weaker ability to capture local features compared global features. In this study, an improved optimiz...

During the last several years we have been investigating ultrasonic techniques for evaluating the quality of solid state weld interfaces [1 ,2]. Promising results have been obtained on a variety of different solid state welds by extracting features from the ultrasonic waveforms and applying pattern recognition algorithms to separate acceptable from unacceptable welds. In general, the primary di...