摘要
针对履带起重机桁架臂初始几何缺陷对其承载能力影响问题,对相关规范和企业标准进行统计整理,将初始几何缺陷分为两类:臂节几何缺陷和臂节组装产生的几何缺陷。对一致缺陷模态法进行改进,在线性屈曲分析的基础上,考虑了缺陷分布的随机性,建立了模态参与系数的概率模型,提出了多阶模态随机耦合法模拟臂节几何缺陷,并采用等效载荷法模拟臂节组装产生的几何缺陷。算例分析表明,理想臂架的临界失稳载荷为392 t,本文所提方法模拟臂架几何缺陷所得最不利临界失稳载荷为361 t,相比降低了7.9%;考虑前四阶单阶模态作为臂节几何缺陷所得最不利临界失稳载荷为368 t。综合上述结果,本文所提几何缺陷模拟方法可以模拟出最不利的缺陷,并且获得最不利缺陷分布下的临界失稳载荷,为桁架臂初始几何缺陷模拟提供一些借鉴和参考。
Aiming at the impact of the initial geometric defects of crawler crane lattice boom on its load-bearing capacity,the relevant regulations and corporate standards are statistically sorted,and the initial geometric defects are classified into two categories:geometric defects of the boom section and geometric defects caused by the assembly of the boom section.The uniform defect model method is improved,and on the basis of linear buckling analysis,a probability model of modal participation coefficients considering the randomness of defect distribution is established.The multi-order modal random coupling method is proposed to simulate the geometric defects of the boom section,and the equivalent load method is used to simulate the geometric defects caused by the assembly of the boom section.The analysis of the calculation example shows that the critical buckling load of the ideal boom is 392 t,and the most unfavorable critical buckling load obtained by simulating the geometric defects of the boom is 361t,which is reduced by 7.9%;,the most unfavorable critical buckling load obtain by considering the first four-order single mode as the boom section geometric defect is 368t.The results indicates that the geometric defect simulation method proposed can simulate the most unfavorable defect and obtain the critical buckling load under the most unfavorable defect distribution,which provides a reference for the simulation of the initial geometric defects of the lattice boom.
作者
王欣
付河灵
陆鹏飞
岳增珂
WANG Xin;FU Heling;LU Pengfei;YUE Zengke(School of Mechanical Engineering,Dalian University of Technology,Dalian 116024,China;Zoomlion Heavy Industry Science and Technology Co.,Ltd.,Changsha 410000,China)
出处
《机械》
2021年第8期52-58,共7页
Machinery
基金
辽宁省创新团队项目(LT2014001)。
关键词
初始几何缺陷
多阶模态随机耦合法
履带起重机
桁架臂
屈曲分析
initial geometric defect
multi-mode random coupling method
crawler crane
lattice boom
buckling analysis
