破损舰体结构疲劳裂纹扩展试验研究

Experimental research on the propagation of a fatigue crack in a damaged warship structure

针对破损舰船的疲劳寿命问题,采用预制缺口的疲劳试样模拟破损舰体结构,利用液压伺服疲劳试验机对舰用疲劳试样进行了拉伸疲劳试验,研究了平板和加筋板预制缺口疲劳试样在拉伸疲劳载荷作用下的裂纹扩展规律,确定了不同疲劳应力幅值作用下疲劳试样裂纹开裂的临界疲劳次数,得出了裂纹长度、疲劳载荷循环次数和疲劳应力幅值之间的拟合关系式,并与高频疲劳试验进行了比较.试验结果对预报破损舰船在波浪中航行时的裂纹扩展情况有重要参考价值.

Aiming to define fatigue life of a with a V type gap to simulate the crack of a damaged warship by using plate and stiffened plate fatigue experiment damaged warship structure, the tensile fatigue test of fatigue experiment steel was completed by a hydraulic servo fatigue test machine. The rule of fatigue crack propagation of fatigue specimerts steel structures was researched under tension fatigue loading, the critical fatigue cycle under different fatigue stress amplitudes was established, the formula on crack length, number of cycles, and fatigue stress amplitude was offered, and the comparison between the low frequency and high frequency fatigue experiment was given. The experiment results may provide a guide for analyzing and predicting crack propagation situations of warships in waves and the remaining life assessment of a damaged warship.