CAJ | 학술논문

船舶等许多工程结构在服役过程中的受载荷历程是一个随机过程.而变幅载荷下的载荷相互作用对疲劳裂纹扩展寿命将产生显著的影响.因此研究随机载荷作用下的裂纹扩展及定量计算对船舶结构的疲劳寿命预测的可靠性是十分重要的.该文提出了一个基于有效应力强度因子,以应力比和裂纹尖端塑性区尺寸为主要参数的随机载荷作用下疲劳寿命预测模型.该模型用于预测几种载荷谱作用下的裂纹扩展试验,结果表明预测结构和实验结果符合得很好.
선박등허다공정결구재복역과정중적수재하역정시일개수궤과정.이변폭재하하적재하상호작용대피로렬문확전수명장산생현저적영향.인차연구수궤재하작용하적렬문확전급정량계산대선박결구적피로수명예측적가고성시십분중요적.해문제출료일개기우유효응력강도인자,이응력비화렬문첨단소성구척촌위주요삼수적수궤재하작용하피로수명예측모형.해모형용우예측궤충재하보작용하적렬문확전시험,결과표명예측결구화실험결과부합득흔호.
Many engineering structures such as ship structures are subjected to random loading in service.The load cycle interactions can have a very significant effect on fatigue crack growth under variable amplitude loading. Study of fatigue crack growth law and fatigue life calculation methods under random loading is very important for the reliable life prediction of ship structures. In this paper,a fatigue life prediction model under random loading,taking the stress ratio and the plastic size near crack tip as main parameters in calculation of effective stress intensity factor range,was proposed. Several cases of fatigue crack growth tests under various spectral loadings were predicted by the present model.The results show that the predicted results are in good agreement with the test data.