塔式起重机结构疲劳寿命的研究

The Study of Structural Fatigue Life of Tower Crane

目的分析塔式起重机关键部位杆件的疲劳寿命.方法在获得该处结构应力谱的基础上,确定了该点的应力循环;并用古德曼图线进行转换,推导出应力比与对称循环应力的关系;利用转换公式,求出等效的对称循环应力;设定标准应力和标准作用次数,将该处结构经历的等效对称循环应力和作用次数转化成标准应力及其作用次数.结果获得了分析这类结构杆件的疲劳损伤和剩余寿命的分析方法.得出了应力比与等效对称循环应力的公式;设定标准应力及标准作用次数,以此为基点,确定计算点处的疲劳寿命.结论通过研究结构上具有一定交变应力作用的杆件疲劳寿命来揭示塔式起重机结构疲劳寿命的分析方法,更注重了载荷在某些截面的处或杆件上的作用效果,为分析塔式起重机其他位置处的结构疲劳提供了新的方法.

The paper is for analyzing the fatigue life of the key member bars of tower crane structure.The character of stress cycle on the examination point was established based on the stress spectrum.The way for establishing the symmetry cyclic stress spectrum was set up by means of the conversion of Goodman Chart.The equivalent symmetrical cyclic stress can be conversed into standard stress and the number of the standard action on the points.The standard stress and the number of the standard action for judging the level of fatigue in the light of the conversion formula.The level of cycle stress corresponds with action number of the the stress to the certain metallic material.Through the study on the structure of alternating stress,the way for discovering the fatigue life of member bars of tower crane structure was obtained.And the formulae have been given for calculating the tower crane structure fatigue life.