CAJ | 학술논문

海洋结构物的疲劳寿命预报是当前的研究热点，文章根据第二作者率领的课题组提出的海洋结构物疲劳寿命预报统一方法比较了疲劳裂纹扩展模拟的三种数值积分方法：逐周数值积分法、△N积分法和△a积分法，并分析了每种方法的适用条件。随后，以中心表面裂纹承受单向交变拉伸载荷的平板为例，分别运用三种方法计算了裂纹扩展寿命和最终裂纹尺寸。同时，研究了△N和△a取值不同对结果的影响。最后，综合考虑计算耗时和计算结果精度，给出了△N积分法和△a积分法的建议值，即△N/N≤1.0%，△a≤0.1 mm。
해양결구물적피로수명예보시당전적연구열점，문장근거제이작자솔령적과제조제출적해양결구물피로수명예보통일방법비교료피로렬문확전모의적삼충수치적분방법：축주수치적분법、△N적분법화△a적분법，병분석료매충방법적괄용조건。수후，이중심표면렬문승수단향교변랍신재하적평판위례，분별운용삼충방법계산료렬문확전수명화최종렬문척촌。동시，연구료△N화△a취치불동대결과적영향。최후，종합고필계산모시화계산결과정도，급출료△N적분법화△a적분법적건의치，즉△N/N≤1.0%，△a≤0.1 mm。
Based on a unified fatigue life predcition (UFLP) method for marine structures developed by the second author’s group, three numerical integration methods are compared to simulate fatigue crack propa-gation: cycle by cycle integration method, integration method by △N, integration method by △a. The appli-cable conditions for each method are also discussed. An example of a plate with a center surface crack sub-jected to remote fatigue loading is chosen to demonstrate the calculation of crack propagation life and final crack sizes using each method. And, the influence of different values of △N and △a on the calculation re-sults is analyzed. Considering the computation time and accuracy comprehensively, suggested values for in-tegration methods by△N and△a are given, namely△N/N≤1.0%,△a≤0.1 mm.