摘要
传统的可靠性模型需要大量的试验数据来描述不确定性参数的分布函数和隶属函数,但由于起重机生产批量、试验成本等多方面因素的限制,对于同一工作环境的起重机来说,可供参考的数据较少。因此,针对小样本的不确定性参数信息量不足的问题,开展有限样本条件下的履带起重机非概率可靠性研究。首先,确定了臂架结构强度、刚度和稳定性可靠性计算准则;其次,以可靠性计算准则为基础,结合区间非概率理论,将履带起重机臂架的额定起重量、起升载荷偏摆角度、起升冲击系数等不确定参数看作区间变量,建立了臂架结构的非概率可靠性模型。该模型仅需知道不确定参数的上下界而无需知道其分布规律,便可求解臂架结构可靠性。最后,通过工程算例验证了该模型的正确性,并进一步分析了臂架类起重机结构的起重量和轴向力变化对非概率可靠性结果的影响。结果表明,用该方法得到的履带起重机区间非概率可靠度大于1,符合实际情况。因此,采用区间非概率模型研究结构的可靠性,既降低了试验成本,也提高了计算的效率。该可靠性模型意义明确,具有很好的经济价值和社会价值,是对传统可靠性模型的补充。
The paper is inclined to carry out the non-probability reliability examination of the crawler cranes under the limited sample conditions via the traditional reliability model.The said model needs to have a large amount of experimental data to describe the distributive function and the membership function of the uncertain parameters,due to the insufficient information of the uncertain parameters.Nevertheless,due to the limitations of a lot of factors,such as the production volume of the crane and the cost of the experiment,there may be hardly sufficient data that can be used for reference to the cranes in the same working environment.And,so,first of all,the reliability calculation criteria for the strength,stiffness and stability of the boom are to be defined and determined.And,then,based on the reliability calculation criteria and the interval non-probability theory,uncertain parameters,such as the rated lifting weights of the crawler crane boom,the yaw angle of the lifting load and the lifting impact coefficient can all be regarded as the interval variables.And,furthermore,we have also established a non-probabilistic reliability model of the boom structure of the crawler crane.And,for the said crawler crane model,it is merely necessary to know the upper and lower bounds of the uncertain related parameters to solve the structural reliability of the boom.And,finally,an engineering example can be used to verify the correctness of the model,with the influence of the change of the lifting weight and the axial force of the jib crane needed to be analyzed on the non-probability reliability.Thus,it can be seen that the nonprobability reliability index of the crawler crane obtained by the above said method should be greater than 1,which is in line with the actual situation.And,therefore,the non-probabilistic models used to calculate the reliability of structures can not only help to reduce the cost of the experiments but also facilitate to heighten the efficiency of calculations.Hence,the non-probabilistic reliability model may enjoy a nice economic and social importance in dealing with the problems of insufficient information on the crane structure,and is,therefore,a nice supplement to the traditional reliability model.
作者
刘丽
杨瑞刚
LIU Li;YANG Rui-gang(Department of Mining Engineering,Luliang University,Luliang 033001,Shanxi,China;College of Mechanical Engineering,Taiyuan University of Science&Technology,Taiyuan 030024,China)
出处
《安全与环境学报》
CAS
CSCD
北大核心
2020年第6期2079-2084,共6页
Journal of Safety and Environment
关键词
安全工程
臂架
履带起重机
非概率
结构可靠性
safety engineering
boom
crawler crane
nonprobability
structural reliability
