桥式起重机随机应力谱获取及疲劳剩余寿命估算  

Random Stress Spectrum Acquisition and Fatigue Residual Life Estimate for Overhead Travelling Crane

作　　者：王爱红[1,2] 徐格宁[2] 高有山[2] 

机构地区：[1]兰州理工大学机电学院,兰州730050 [2]太原科技大学机械工程学院,太原030024

出　　处：《机械工程学报》2012年第18期192-198,共7页Journal of Mechanical Engineering

基　　金：'十二五'国家科技支撑计划(2011BAK06B05-05);山西省青年科技基金(2009021025);博士启动基金(20102010);山西省自然科学基金(2012011025-5);山西省高等学校科技(20120023)资助项目

摘　　要：为估算桥式起重机金属结构疲劳剩余寿命,保证起重机使用安全,需要获取结构疲劳核算点应力谱。起重量、起升卸载位置和起重小车是否过中点是获取应力谱的特征参数。通过现场采集特征参数数据,经统计检验,建立特征参数的概率分布模型。采用拉丁超立方抽样,产生特征参数随机数样本,以动态仿真计算疲劳核算点的应力—时间历程,以雨流计数获得双参数应力谱,运用Forman公式估算疲劳剩余寿命。用上述方法对样机进行仿真计算,获得检测周期内10级应力谱,剩余疲劳寿命为32.8年,与试验应力谱计算的疲劳剩余寿命误差为6.26%。试验结果表明,采用仿真应力谱替代试验应力谱进行疲劳剩余寿命评估是可行的,所提出基于'实测+统计+抽样+比对+仿真'组合策略的起重机载荷谱获取和疲劳剩余寿命评估方法,具有周期短、成本低的优点。It is necessary to obtain the stress spectrum of structural fatigue accounting point in order to estimate the fatigue residual life of metal structure of overhead travelling crane and ensure crane safety.The characteristic parameters of stress spectrum are lifting weight,lifting position,unloading position and whether through the midpoint of span.The probability distribution model of the characteristic parameters is built with the data by collected characteristic parameters on the spot and statistical tested.Random samples of the characteristic parameters are produced with the Latin hypercube sampling（LHS）.Stress-time history of the fatigue accounting point is calculated by dynamic simulation model and double parameter stress spectrum is obtained by rain flow counting model.Fatigue residual life is estimated by Forman formula.Prototype simulated with the above method,the 10 levels stress spectrum is obtained in detection period,and the fatigue residual life is estimated as 32.8 years.The error of remaining fatigue life is 6.26% between in simulation stress spectrum and test stress spectrum.It is feasible that test stress spectrum were replaced by simulation stress spectrum for the remaining fatigue life assessment.The method has the merit of short cycle,low cost based on the combination strategy of ＂testing,statistics,sample and contrast＂ for load spectrum acquisition for overhead travelling crane and the remaining fatigue life assessment.

关 键 词：应力谱 动态仿真 雨流计数法 疲劳剩余寿命 

分 类 号：TH21[机械工程—机械制造及自动化]