循环载荷作用下铝合金船体板架结构疲劳特性研究

Research on fatigue characteristics of aluminum alloy hull plate-frame structure under cyclic load

为研究铝合金船体板架结构疲劳特性,寻求循环载荷作用下船体板架结构疲劳寿命变化规律。本文以铝合金船体板架结构为研究对象,设计制作不同节点实尺度板架模型,开展循环载荷作用下铝合金船体板架结构疲劳试验,获取试验中测点应力与循环加载次数等数据,并采用Ansys/Fe-safe平台建立模型进行疲劳仿真分析,将仿真得到节点板架S-N曲线与试验结果进行对比分析。结果表明:1)铝合金板架结构疲劳破坏模式存在一般性规律,节点2板架疲劳性能更好;2)试验与仿真得到节点板架疲劳裂纹萌生及破坏位置一致,且试验测得热点应力、循环寿命与仿真水平基本相当,揭示了节点板架结构断裂原因在于高载循环应力下产生的疲劳损伤;3)拟合得到试验与仿真S-N曲线吻合度较高,且试验曲线更偏于保守、安全。研究成果可为铝合金船体板架结构疲劳强度评估及寿命预测提供参考。

Researching on fatigue characteristics of typical node plate-frame structure of the aluminum alloy hull, seeking the rule of hull plate-frame structure fatigue life under cyclic high load. Based on aluminum alloy hull plate-frame structure as the research object, designing and producing real scale frame model for different node forms, conducting fatigue experiment of the plate-frame structure of aluminum alloy hull under recycle high load, getting in the process of measured data including equivalent stress and cyclic loading times from fatigue experiment. And modeling fatigue simulation analysis based on ANSYS/Fe-safe platform,Fitting experiment and simulation S-N curve for different node plate-frame structure. As a result, 1.Two nodes plate-frame structure fatigue damage exists general rule, The fatigue property of node 2 frame structure is better; 2. The result of experiment and simulation show that node plate-frame structure fatigue damage locations and forms are basically identical, and the same as equivalent stress and fatigue life level, which verifys the reliability of experiment results, revealing node plate-frame structure fracture due to cyclic stress fatigue; 3. The experiment fitting S-N curve is similar to simulation. Besides, the experiment curve is more conservative and safe, which could provide the reference of fatigue strength assessment and life prediction for aluminum alloy hull plate-frame structure.