基于疲劳试验的桥式起重机金属结构可靠性理论研究

发布时间：2018-03-12 13:17

本文选题：桥式起重机　切入点：金属结构　出处：《太原科技大学》2011年硕士论文　论文类型：学位论文

【摘要】：金属结构是桥式起重机最重要的部分,因此,本文致力于研究桥式起重机金属结构的疲劳试验和可靠性理论。本文结合试验,应用机械疲劳应用统计学、概率断裂力学、工程结构可靠性理论及应用等理论,取得了以下研究结论: 1.证明了桥式起重机焊接箱形主梁对数疲劳寿命满足正态分布,建立了常幅载荷下主梁疲劳寿命的指数函数表达式,变幅载荷下总损伤量满足修正Miner线性累积损伤定律,并且服从正态分布。 2.建立了桥式起重机焊接箱形主梁在常幅载荷和变幅载荷下累积损伤可靠性分析模型。 3.首次推导出变幅载荷下计算裂纹扩展paris公式中C值的公式,应用机械疲劳应用统计学,计算出C值服从对数正态分布。 4.建立了桥式起重机焊接箱形主梁在常幅载荷和变幅载荷下概率断裂力学可靠性分析模型。 5.给出了应用应变法测量焊接箱形梁的断裂韧度的方法,并结合试验得到了焊接箱形梁焊缝材料的断裂韧度。
[Abstract]:Metal structure is the most important part of bridge crane. Therefore, this paper is devoted to study the fatigue test and reliability theory of metal structure of bridge crane. The theory of engineering structure reliability and its application have obtained the following conclusions:. 1. It is proved that the logarithmic fatigue life of welded box girder of bridge crane meets normal distribution, and the exponential expression of fatigue life of main beam under constant amplitude load is established. The total damage under variable amplitude load satisfies the modified Miner linear cumulative damage law. And from the normal distribution. 2. The cumulative damage reliability analysis model of welded box girder of bridge crane under constant amplitude load and variable amplitude load is established. 3. The formula of C value in the paris formula of crack propagation under variable amplitude loading is derived for the first time, and the logarithmic normal distribution of C value is calculated by applying statistics of mechanical fatigue. 4. The reliability analysis model of probabilistic fracture mechanics for welded box girder of bridge crane under constant amplitude load and variable amplitude load is established. 5. The method of measuring the fracture toughness of welded box beam by strain method is presented, and the fracture toughness of welded box beam weld material is obtained by combining the test.
【学位授予单位】：太原科技大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH215;TB114.3

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