Fracture Analysis on the Ⅰ/Ⅱ Mixed Cracks between Spiral Welded Pipe and UOE Welded Pipe

Based on the maximum tension stress, the paper analyzed the cracking angle θ0 and crack angle β of Ⅰ/Ⅱ mixed cracks at weld zone with pipe loaded by pressure and residual stress, and discussed the advantages and disadvantages of fracture strength between spiral welded pipe and UOE welded pipe under different cracks flaw.