CAJ | 학술논문

针对船体结构疲劳断裂问题,以船用Q235钢为研究对象,开展一系列紧凑拉伸试样裂纹扩展速率试验,分别采用柔度法和图像法测量裂纹长度,应用七点递增多项式法及最小二乘法对试验数据进行拟合回归,并比较2种方法的准确性及稳定性. 在对试验数据进行统计特性研究的基础上,得到裂纹扩展参数C、m的统计规律. 最后结合概率断裂力学理论,给出不同概率水平下的裂纹扩展速率公式. 为进一步研究含裂纹的复杂船体结构裂纹扩展特性及疲劳可靠性提供了理论依据及试验基础.
침대선체결구피로단렬문제,이선용Q235강위연구대상,개전일계렬긴주랍신시양렬문확전속솔시험,분별채용유도법화도상법측량렬문장도,응용칠점체증다항식법급최소이승법대시험수거진행의합회귀,병비교2충방법적준학성급은정성. 재대시험수거진행통계특성연구적기출상,득도렬문확전삼수C、m적통계규률. 최후결합개솔단렬역학이론,급출불동개솔수평하적렬문확전속솔공식. 위진일보연구함렬문적복잡선체결구렬문확전특성급피로가고성제공료이론의거급시험기출.
Aiming at the fatigue fracture problem occurred in the hull structure, taking the marine steel Q235 as the research object, a series of crack propagation rate tests of compact tension specimens were conducted. A compliance method and a pixel method were introduced to measure the crack length, and the two methods were compared re-spectively in accuracy and stability. The incremental polynomial method of 7 elements and the least square method were applied to fitting and regressing of the crack test data. Then using statistical analysis, the statistical character-istics of crack propagation parameters C and m were obtained. On the basis of probability fracture mechanics theory, the functions of crack propagation rate under different probability standards were presented. In conclusion, this pro-vides a theoretical basis and experimental foundation for the research of crack propagation characteristics and fatigue reliability of complex ship hull structures.