摘要
为了保证通用桥式起重机的工作安全,建立疲劳寿命预测的数值仿真模型,并结合结构疲劳危险点的疲劳应力-时间历程来评估起重机金属结构的疲劳剩余寿命。以Q235B钢疲劳裂纹扩展试验为基础,获得6组被测CT试件的a-N数据及其对应点的da/dN和ΔK数据,通过线性回归拟合出Paris裂纹扩展模型的参数C和m。通用桥式起重机在实际使用中所受的载荷是随机的,无法直接应用Paris公式进行寿命估算。以某企业正在服役的50/10 t通用桥式起重机为研究对象,统计其在一定时间段内的载荷-时间历程数据,通过有限元仿真获得对应的样本应力-时间历程,采用周期样本循环法,对通用桥式起重机剩余寿命进行评估。结果表明,利用断裂力学中疲劳裂纹扩展理论结合应力谱评估焊接箱形梁疲劳剩余寿命的方法是可行的,可为起重机维护管理提供参考。
To assess the fatigue remaining life of the metal structure of a general-purpose bridge crane and ensure the safety of the crane,this study established a numerical simulation model and combined it with the fatigue stress spectrum of the structural fatigue risk point to evaluate the residual life.In this paper,the fatigue crack growth test of 6 groups of measured CT samples of Q235 B steel was carried out at 20℃by using the K-increasing test method.The fatigue crack growth life test data(a-N)of the corresponding samples and the data of C and m at the corresponding points were analyzed and the parameters C and m values of the crack growth model based on the Paris formula were fitted by linear regression.In practical engineering applications,the load on a general-purpose bridge crane is random,and the Paris formula cannot be directly used for life calculation.Therefore,this article takes a 50/10 t general-purpose bridge crane in service in a certain enterprise as the research object,and it is determined by statistics.For the load spectrum data in the period,the periodic sample cycle method is used to cycle the sample stress spectrum obtained by the finite element simulation method as the stress spectrum,and the obtained stress spectrum is brought into the numerical simulation of the crane fatigue remaining life prediction under random stress.In the model,the remaining life of the general bridge crane is evaluated.The test results show that the fatigue crack propagation theory in fracture mechanics combined with the stress spectrum method is used to evaluate the life of welded box girder of general-purpose bridge crane from the initial crack length of 0.5 mm to the critical crack length of 97 mm,which is about 19.17 years,which meets the requirements of the remaining service life in the design life.This method provides an important reference for crane maintenance and management.
作者
渠晓刚
张晓康
焦松岩
高杰
QU Xiao-gang;ZHANG Xiao-kang;JIAO Song-yan;GAO Jie(College of Mechanical Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,China)
出处
《安全与环境学报》
CAS
CSCD
北大核心
2022年第3期1284-1290,共7页
Journal of Safety and Environment
基金
山西省重点研发计划项目(202003D111008)。
关键词
安全工程
疲劳剩余寿命
通用桥式起重机
断裂力学
载荷-时间历程
数值仿真
safety engineering
fatigue remaining life
general-purpose bridge crane
fracture mechanics
load spectrum
numerical simulation
