密排阵列孔柱层板冷却结构服役寿命预测分析

层板冷却结构的服役可靠性直接影响发动机的使用安全，利用数值模拟方法分析了典型的密排阵列孔柱层板冷却结构，激光焊接过程及服役过程中温度和应力场分布规律，并依据模拟结果利用Morrow修正的Manson-Coffin公式进行了层板冷却结构的热疲劳寿命评估. 结果表明，层板孔道区域服役状态受焊接残余应力的影响很小，而服役过程对其影响较大，热应力幅值在孔道及附近区域达到最大，为焊缝区域热应力幅值的1.6倍，属于服役过程中的危险区域，预估此处的疲劳寿命受热疲劳影响较大，为此类结构实际应用中应重点关注的关键区域.

Research on service life prediction of closely spaced array hole column laminated cooling structure

The service reliability of the laminar cooling structure directly affects the service safety of the engine. In this study, numerical simulation method was used to analyze the distribution of temperature and stress field in the laser welding process and service process of the typical closely spaced array hole column laminar cooling structure. According to the simulation results, the thermal fatigue life of the laminar cooling structure was evaluated by using the Morrow modified Coffin-Manson formula. The results show that the service state of the laminar passage area was little affected by the welding residual stress, but the service process has a great impact on it. The thermal stress amplitude in the laminar passage and nearby area reached the maximum, which was 1.6 times of the thermal stress amplitude in the weld area. It belongs to the dangerous area in the service process. It is estimated that the fatigue life here is greatly affected by thermal fatigue, which should be paid attention to in practical application.