低屈服点钢LYP100单调与循环拉伸试验研究

Experimental Study of Low Yield Point Steel LYP100 under Monotonic and Cyclic Tensile Loading

对47个LYP100低屈服点钢焊接试件进行单向拉伸和反复拉伸加载试验,研究其在不同加载制度下的应力-应变曲线、荷载位移曲线、骨架曲线、破坏机理和延性特征.结果表明:试件横截面厚度是影响其耗能能力的重要因素,12mm试件的耗能能力明显优于6mm试件;焊接接头对试件的破坏有不利影响,带焊接接头的试件在循环加载作用下疲劳损伤累积效应显著,容易发生脆性破坏,延性变差;LYP100低屈服点钢与Q345钢、Q460钢焊接后,试件的强度提高,循环荷载作用下强度硬化现象明显,但是其延性变差.

By testing the properties of 47 LYP100 low-yield steel specimens under both monotonic and repeated tensile loading,the stress-strain curve,load-displacement curve,skeleton curve,failure mechanism and ductility characteristics of each specimen were studied.The results show that the cross-sectional thickness of specimens is the main factor affecting the energy consumption of steel,and the energy dissipation capacity of 12mm thick specimens is much better than that of 6mm specimens.The welded joint has an adverse effect on the damage of the specimen.The fatigue damage accumulation effect of specimens with welded joint under cyclic tensile loading is significant,and brittle fracture is prone to cause the ductility of the test piece to deteriorate.After the low yield point steel LYP100 is welded with Q345 steel or Q460 steel,the strength of specimen is improved,and the strength hardening phenomenon under the cyclic tensile load is obvious,but the ductility is deteriorated.