船用铝合金板架结构典型节点的疲劳试验研究

Experimental study of fatigue properties of aluminium alloy plate

本文针对船用铝合金板架结构典型节点的疲劳性能开展了试验研究。首先采用X射线对焊缝部位进行了拍照,获得了焊缝处的微观缺陷特征;然后进行板架的极限承载能力试验,得到板架的极限载荷水平;接着采用不同载荷水平进行反复载荷作用下的疲劳试验,获得了不同载荷水平下典型节点的疲劳寿命和破坏模式。试验结果表明:船用铝合金板架结构典型节点的疲劳寿命与测点应力呈双对数线性关系,即随着对数测点应力的增大,对数疲劳寿命呈线性下降趋势;而焊缝缺陷形式直接关系到节点的疲劳破坏模式与疲劳寿命。研究结果可为船用铝合金板架结构的承载能力评估与焊接工艺设计提供参考。

The fatigue properties of typical node of aluminum alloy plate frame structure was investigated experimently.Firstly,the X-ray is used to photograph the weld area,and the microflaw characteristics of the weld are obtained.Then the ultimate load test of the plate frame is carried out and the ultimate load level of the plate frame is obtained.And the fatigue life and failure mode of typical nodes under different load levels are obtained by using the fatigue test under repeated loads with different load levels.Test results show that the marine aluminum alloy frame structure fatigue life of typical nodes had double logarithm linear relationship with the measured stress,namely with the increase of the logarithmic measured stress,the logarithmic fatigue life appears linear decline;the weld defect form is directly related to the fatigue failure mode and fatigue life of the joints.The results can serve as a reference for the evaluation of the bearing capacity and the design of the welding process of marine aluminum alloy plate frame structures.