In the consideration of circumferential weld imperfection,a great amount of nonlinear numerical analyses are conducted to investigate the stability of the cylindrical shells when the cylinders are subjected to partial axial compression with the loading subtended angle being less than 10°.

In order to detect weld defects in steel tube,we set up a realtime imaging and detecting system.

Final,gives an analysis of forming cause of welding seam defect and puts forward some preventing measures.

Automatic inspection of weld defects using X-ray image sequences;

Size Error Analysis of Weld Defect by Routine Ultrasonic Examination;

But unfortunately, due to limitation of conditions, there is not yet a systematic research at home on the online ultrasonic detection of weld defects of pressure vessels and pipelines in high temperature environment.

Study on the automatic grading system for weld flaw on the radiogragh;

Study on the partition of digital image of weld flaw on radiogragh;