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起重机结构相关变量由于缺乏试验数据,数据统计结果往往存在一定的不确定性,很难准确地用概率模型来描述,而且,概率可靠性对概率模型参数十分敏感,概率数据很小的误差都可能导致结构可靠性计算出现较大误差。基于此,提出了基于区间分析的起重机结构非概率可靠性方法。在实际工程结构中,有时虽然不能得到不确定参数的精确概率分布,但这些参数所处的范围或界限却易于确定,非概率可靠性分析方法可以将机械结构的不确定性参数用非概率区间分析描述。该方法将区间分析与结构可靠性进行结合,研究了具有区间特性的设计参数与结构响应之间的映射关系,通过计算机械结构功能函数中强度和应力的区间范围,给出了描述结构非概率满意度可靠性指标的计算方法。利用区间运算规律确定了起重机结构非概率满意度可靠性指标的求取步骤。以起重机结构为实例,运用基于区间分析的非概率可靠性分析方法,计算了起重机臂架的可靠度,同时分析了区间运算中区间扩张问题。实例表明,运用区间分析能够较准确地描述起重机结构的可靠性问题。
Due to the lack of experimental data, the statistic results of the crane often have some uncertainties, so it is difficult to describe the probability model accurately. Moreover, the probability reliability is very sensitive to the parameters of the probability model and the error with small probability data may be Resulting in greater reliability of the calculation of the structure error. Based on this, a non-probabilistic reliability method of crane structure based on interval analysis is proposed. In the actual engineering structure, although the exact probability distribution of uncertain parameters can not be obtained sometimes, the scope or limit of these parameters can be easily determined. The non-probabilistic reliability analysis method can use the uncertainty of mechanical structure parameters with non-probability interval Analyze the description. The method combines interval analysis with structural reliability, and studies the mapping relationship between design parameters and structural response with interval characteristics. By calculating the range of strength and stress in the mechanical function of mechanical structure, Satisfaction reliability index calculation method. Using the law of interval operation, the procedure of obtaining the reliability index of non-probabilistic satisfaction of crane structure is determined. Taking the crane structure as an example, the reliability of the crane boom is calculated by the non-probabilistic reliability analysis method based on interval analysis. Meanwhile, the interval expansion problem in the interval operation is analyzed. The example shows that using the interval analysis can describe the reliability of the crane structure more accurately.