摘要
转子是涡轮增压器高速旋转部件,在运行中承受高低周疲劳载荷,其安全运行尤为重要。为获得涡轮增压器叶片的高低周疲劳寿命,通过改变高低周疲劳中高周应力比和单个复合疲劳载荷块中的高周频率,分析疲劳寿命特征,建立了基于Miner理论的寿命评估模型,利用此模型分析得出160000 r/min转速下涡轮叶片的高低周复合疲劳寿命。通过有限元分析软件对相同转速下涡轮叶片进行应力分析,得到低周应力、高周应力的最大值及其关键部位,并对涡轮叶片进行模态分析与谐响应分析,结合Ncode商用软件得出叶片关键部位高低周复合疲劳寿命。对基于Miner理论的寿命评估模型和Ncode软件所预测的叶片高低周寿命结果比较发现,随着高低周载荷谱中高周应力、高周循环数逐渐增加,修正后的模型所得寿命与Ncode软件所得寿命均呈递减趋势,寿命误差在两倍范围之内,两种方法均能较为可靠地预测高低周复合疲劳工况下的叶片疲劳寿命,而基于Miner理论的寿命修正模型的使用相对较为方便,所求寿命较为可靠,易于在工程中推广应用。
The rotor is a high-speed rotating part of turbocharger,which is subjected to high and low cycle fatigue load in operation.Its reliability during operation is particularly important.In order to obtain the high and low cycle fatigue life of turbocharger blade,the fatigue life characteristics were analyzed by changing the high and low cycle composite stress ratio and the high cycle frequency in a single fatigue load block,and a life evaluation model based on Miner's theory was established.The high-low cycle composite fatigue life of turbine blades at 160000 r/min was obtained by using this model.Finite element analysis software was used to conduct stress analysis on turbine blades at the same speed to obtain the maximum values of low cyclic stress and high cyclic stress and their critical positions.Modal analysis and harmonic response analysis were carried out on turbine blades,and combined with Ncode commercial software,the high-low cycle composite fatigue life of critical parts of blades was obtained.The comparison between the life evaluation model based on Miner's theory and Ncode software shows that the life obtained by the revised model and the life obtained by Ncode commercial software show a decreasing trend with the increasing number of high-cycle stress and high-cycle fatigue in the high and low-cycle load spectrum,and the life error is within twice.Both of the two methods can reliably predict the fatigue life of the blade under the condition of high-low cycle composite.The life modification model based on Miner's theory is more convenient to use,and the life obtained is more reliable,which is easier to be applied in engineering practice.
作者
崔璐
刘阳
王澎
罗浩
魏文澜
李臻
CUI Lu;LIU Yang;WANG Peng;LUO Hao;WEI Wen-lan;LI Zhen(Mechanical Engineering College, Xi'an Shiyou University, Xi'an 710065, China;HYCET Engine System (Jiangsu) Co., Ltd., Zhenjiang 212214, China)
出处
《科学技术与工程》
北大核心
2022年第5期1887-1897,共11页
Science Technology and Engineering
基金
国家自然科学基金(51305348,51901180)
陕西高校青年创新团队项目和西安石油大学研究生创新与实践能力培养计划(YCS19213125)。
关键词
涡轮叶片
高低周耦合损伤
复合应力比
复合载荷块高周循环次数
turbocharger turbine blades
high and low cycle fatigue
stress ratio of combined cycle
times of high cycle fatigue in combined cycle load spectrum
作者简介
第一作者:崔璐(1979—),女,汉族,陕西西安人,博士,教授,研究方向:特殊环境下机械设备强度安全、疲劳损伤理论与工程,E-mail:cuiluxa@hotmail.com;通信作者:王澎(1976—),男,汉族,辽宁抚顺人,博士,高级工程师,研究方向:动力设备零部件安全评价,E-mail:wp168@hotmail.com。
