CAJ | 학술논문

该文提出一种基于有限元法的塔式起重机钢结构疲劳寿命估算的方法.首先建立塔式起重机有限元模型并计算静应力,再确定载荷时间历程.将塔式起重机所受的疲劳载荷划分为变幅载荷和冲击载荷.对于变幅载荷,采用现场观测数据并运用数理统计的方法,揭示出变幅小车在起重臂下弦杆的每跨轨道上运行的频数与起重臂的坐标成正态分布.以1 d为1个周期,计算出变幅载荷的时间历程.对于冲击载荷,采用瞬态响应方法,得到主要工况下起升钢丝绳内的内力时间关系,获得冲击载荷的时间历程.将塔式起重机结构静应力值、变幅载荷时间历程、冲击载荷时间历程和材料疲劳属性输入MSC.FATIGUE软件,计算得到其钢结构的疲劳寿命.
해문제출일충기우유한원법적탑식기중궤강결구피로수명고산적방법.수선건립탑식기중궤유한원모형병계산정응력,재학정재하시간역정.장탑식기중궤소수적피로재하화분위변폭재하화충격재하.대우변폭재하,채용현장관측수거병운용수리통계적방법,게시출변폭소차재기중비하현간적매과궤도상운행적빈수여기중비적좌표성정태분포.이1 d위1개주기,계산출변폭재하적시간역정.대우충격재하,채용순태향응방법,득도주요공황하기승강사승내적내력시간관계,획득충격재하적시간역정.장탑식기중궤결구정응력치、변폭재하시간역정、충격재하시간역정화재료피로속성수입MSC.FATIGUE연건,계산득도기강결구적피로수명.
A new method was presented which was based on finite element method to predict the fatigue life of tower crane's steel structure. With the method, the finite element model of tower crane was developed and the static stress was calculated. And then time history was defined. It was found that there were two main types of fatigue loads acting on tower crane, which were the amplitude load and the impact load. For the amplitude load, a method with field observation and statistical method was proposed and it was found that the frequency of the trolley-jib slipping the stride on the orbit and the beam's coordinate showed statistically normal distributions. And time history of amplitude load was calculated with one day as a cycle. For impact load, taking transient response method, the relationship between internal stress and time was established for main working conditions and the time history was obtained. Taking the static stress of tower crane, time course of amplitude load and time history of impact load as inputs, the fatigue life of steel structure was obtained with the software of MSC. FATIGUE.