长期主动变位下FAST索网支承结构疲劳寿命分析  

Fatigue analysis of FAST cable-net structure under long-term active shape-changing work

作　　者：范峰[1] 金晓飞[1] 钱宏亮[1,2] 

机构地区：[1]哈尔滨工业大学,黑龙江哈尔滨150090 [2]哈尔滨工业大学(威海),山东威海264209

出　　处：《建筑结构学报》2010年第12期17-23,共7页Journal of Building Structures

基　　金：国家自然科学基金跨学科交叉重点项目(10433020);国家自然科学基金天文联合基金项目(10778615)

摘　　要：研究分析了500m口径射电望远镜(Five-hundred-meter Aperture Spherical Telescope,简称FAST)反射面索网支承结构的疲劳性能。模拟FAST主动变位工作模式(长时巡天观测和随机独立观测),计算30年设计基准期内连续工作运行的次数需求,分析FAST索网支承结构变位工作的随机疲劳应力历程,并基于简单抽样技术,对全寿命疲劳应力历程进行简化,采用实时雨流计数法进行分解;基于S-N试验曲线和Smith等效疲劳寿命极限应力线图,采用Miner线性损伤累积准则分析各索的疲劳寿命。以所有单索疲劳寿命的最小值作为整体结构疲劳寿命,多次模拟计算,统计分析保证率为99.9%的结构疲劳寿命,并合理选取安全系数2.0考虑疲劳寿命变异性影响。分析结果表明,在设计基准期内,结构疲劳寿命满足安全要求,结构疲劳危险区域主要分布在索网中心区域。Structural fatigue property of the adaptive cable-mesh reflector of Five-hundred-meter Aperture Spherical radio Telescope（FAST） was analyzed.According to the active shape-changing working pattern（longtime sky survey and independent random tracing observation） of FAST,the required times of continuously running all year daily in design reference period of 30 years was computed,and the corresponding random fatigue stresses of FAST cable-net structure were analyzed,then the typical fatigue stress piece was put forward based on simple sampling and was decomposed by real-time rain-flow counting algorithms.Subsequently,the fatigue lives of each cable were computed by Miner linear accumulative damage criterion,which was based on the S-N curve of Chinese steel strand（1860N/mm2） and Smith fatigue limited diagram for equivalent life.Taking the minimum fatigue life of all cables as the fatigue life of the overall structure,the life with a guaranteeing probability of 99.9% was analyzed statistically after many stochastic simulations of the typical fatigue stress piece,and a suitable service life factor which is 2.0 was applied in order to take into account the variability of fatigue life.The results show that the fatigue life of FAST cable-net structure can meet the safety requirement in design reference period,and the structural fatigue dangerous region is located in the central part of the cable-net.

关 键 词：FAST索网结构 实时雨流 Miner线性损伤累积准则 疲劳寿命 

分 类 号：TU393.302[建筑科学—结构工程]