CAJ | 학술논문

提出了一种多轴向随机激励下结构疲劳寿命估计的频域分析方法。首先，对结构进行频响分析，得到在基础加速度激励下的应力频响函数矩阵，通过随机振动分析，得到结构应力的功率谱密度矩阵；其次，采用等效的Von Mi-ses应力功率谱密度将多轴应力问题转化为单轴应力问题；最后，利用单轴应力疲劳寿命估计的频域分析方法对结构疲劳寿命进行估计。对一典型构件在多轴向随机激励下的疲劳寿命进行了计算，并与实验结果进行了对比。另外，对构件在多轴向同时激励与单轴分别激励的疲劳损伤结果进行了对比分析，表明多轴向同时振动具有明显的多轴效应，因此进行多轴向振动疲劳研究十分必要。
제출료일충다축향수궤격려하결구피로수명고계적빈역분석방법。수선，대결구진행빈향분석，득도재기출가속도격려하적응력빈향함수구진，통과수궤진동분석，득도결구응력적공솔보밀도구진；기차，채용등효적Von Mi-ses응력공솔보밀도장다축응력문제전화위단축응력문제；최후，이용단축응력피로수명고계적빈역분석방법대결구피로수명진행고계。대일전형구건재다축향수궤격려하적피로수명진행료계산，병여실험결과진행료대비。령외，대구건재다축향동시격려여단축분별격려적피로손상결과진행료대비분석，표명다축향동시진동구유명현적다축효응，인차진행다축향진동피로연구십분필요。
A frequency domain method for fatigue life prediction of structures under multi-axial random excitations was presented.The transfer function matrix from the excitation accelerations to the response stresses was obtained through frequency response analysis.According to the random vibration theory,the PSD matrix of stress response was calculated. Then,the multi-axial stress problem was translated to a uniaxial stress problem via equivalent PSD of Von Mises stress and the uniaxial frequency domain fatigue analysis was used for the fatigue life prediction.The fatigue life of a typical component under the multi-axial random excitations was calculated and compared with the test results.In addition,the fatigue damages of the component caused by the simultaneous multi-axial and uniaxial excitation were analyzed and compared and the multi-axial effect was also analyzed.The result shows the necessity of the application of multi-axial excitations in fatigue life prediction.