摘要
我国公路桥梁设计规范没有给出允许的最大钢板厚度,铁路桥梁规范允许的最大钢板厚度为50mm,欧洲钢桥设计规范中允许使用的最大板厚相对较厚。以防止钢桥疲劳和断裂为目标,提出一种钢材选材和钢板最大允许厚度的确定方法。疲劳裂纹的扩展采用断裂力学理论,裂纹端部的应力强度因子基于同时考虑脆性断裂和塑性屈服断裂影响的R6破坏模式,采用冲击功和相应温度确定含裂纹钢板的低温断裂韧性,并考虑了桥梁中焊接残余应力,加载的应变速率,钢板弯曲成型等因素对最大允许板厚的影响。根据以上理论和方法开发了计算程序,并以重庆市江津观音岩长江大桥为例,确定了钢材的种类和允许的最大钢板厚度。
Permissible maximum plate thickness is not given in the China road steel bridge design specification,while it is determined as 50mm in China railway steel bridge design specification.The maximum plate thickness in Eurocode is bigger than those of China steel bridge design code.A method to assess the permissible maximum plate thickness and choose steel bridge material is presented,whose goal is to prevent fatigue and fracture.The crack propagation adopts the principles of fracture mechanics theory.The determination of stress intensity factor of crack tips is based on the R6 failure method,which takes into account the risk of brittle fracture and plastic collapse.Low-temperature fracture toughness is determined by Charpy impact test energy and corresponding temperature.and some factors,such as welding residual stress,strain rates of loading and forming degree of steel plate,are taken into account.Computer software was developed and used on the determination of steel material type and the permissible maximum plate thickness of Jiangjin Guanyinyan Yangtze River bridge in Chongqing,China.
出处
《土木工程学报》
EI
CSCD
北大核心
2012年第10期145-151,共7页
China Civil Engineering Journal
基金
铁道部科技项目(2010G004-B
20110019A)
关键词
断裂韧性
应力强度因子
允许最大钢板厚度
缺口冲击功
钢桥
fracture toughness
stress intensity factor
permissible maximum plate thickness
charpy impact test energy
steel bridge
