The Feasibility Analysis on Preloading Mode in Pipe Transverse Tensile Test

In transverse tensile test of SAWH pipe body,the test data of yield strength(Rt 0.5) and yield ratio changed greatly.The tensile tests of three kinds of specimens were compared,such as preloading specimen,without preloading specimen and ideal condition specimen,the results showed the degree of specimen flat was the main effect factor on test data.It discussed feasibility of adopting preloading method to carry out transverse tensile test for pipe body,put forward adopting once flatted specimen and low loading can decrease test data;preloading to high grade specimens and such specimens are not easy to be flatted,and loaded force should not exceed yield strength of material.