To solve the problems of complicated,unpredictable bolts stress,the stress and strain characteristics and evolution rules of normal and defective screw-thread steel bolts in different working conditions are analyzed by numerical simulation based on laboratory tensile testing and DIC monitoring.The results show that,the maximum stress,maximum true strain and maximum plastic strain of anchor rods increases gradually with the increase of load values and types,generally presenting an increasing tendency.When the bolt has defects,the stress and strain on defects are obviously concentrated,the shape and location of defects will affect the stress and strain distribution.Due to the existence of screw-thread steel,transverse ribbed structures and defects,local stress and strain are concentrated on rods and the plastic strain turns larger.The sites of plastic strain concentration are prone to develop into the source of cracks under the influences of high load and corrosion,which leads to the failure of bolt breakage.The research results can provide a reference for bolt structure optimization,condition monitoring and service life prediction.
关键词
螺纹钢锚杆/锚杆结构/应力应变/塑性应变/拉伸测试
Key words
screw-thread steel bolt/bolt structure/stress and strain/plastic strain/tensile test
维普
万方数据