摘要
裂纹扩展特性是含缺陷发动机药柱结构完整性分析的前提。利用非固有内聚力模型,在有限元方法的基础上结合网格拓扑操作,发展了裂纹扩展仿真方法。以圆管发动机为例,研究了指数型点火压力作用下裂纹扩展的规律。研究结果表明,裂纹张开位移、裂尖横向位置在加载初期增速较大,加载末期增速较缓;随着压力因子绝对值、初始裂纹深度的增加,以及内表面均布裂纹数量的减少,裂纹张开位移会增大;压力因子绝对值越大,点火压力越大,裂纹也越容易提前扩展。初始裂纹深度的增加会在加载初期提前导致裂纹的扩展,在加载的后期,初始裂纹深度的增加反而会延迟裂纹扩展的时间。在加载的后期,尽管裂纹累计扩展次数一致,但裂纹数的增加会导致裂纹张开位移的减小,进而延迟裂纹扩展的时间。
Crack propagation characteristics is a prerequisite for structural integrity analysis of motor grain containing defects.Based on the finite element method and mesh topology operation,the crack propagation simulation method was developed by using the extrinsic cohesive zone model.Taking a circular propellant grain as an example,the law of crack propagation under exponential ignition pressure was studied.The results show that the crack opening displacement and the transverse position of crack tip increase greatly at the initial stage of loading,but slowly at the end of loading.With the increase of absolute value of the pressure factor,the initial crack depth,and the reduction of the number of uniformly distributed cracks on the inner surface,the crack opening displacement will increase.The larger the absolute value of pressure factor is,the larger the ignition pressure is,and the easier the crack propagates in advance.The increase of the initial crack depth will make the crack propagate in advance at the initial stage of loading.In the later stage of loading,the increase of initial crack depth will make crack propagation delay.In the later stage of loading,although the cumulative crack propagation numberis consistent,the increase of crack number will lead to the decrease of crack opening displacement,and then delay the crack propagation time.
作者
崔辉如
喻尧
王晓东
吕轩
许玉荣
CUI Huiru;YU Yao;WANG Xiaodong;LYU Xuan;XU Yurong(College of Defense Engineering,Army Engineering University of PLA,Nanjing 210007,China;Hubei Sanjiang Aerospace Jianghe Chemical Technology Co.Ltd.,Yichang 444200,China;Hubei Key Laboratory of Advanced Aerospace Propulsion Technology,Wuhan 430040,China)
出处
《固体火箭技术》
CAS
CSCD
北大核心
2023年第5期763-769,共7页
Journal of Solid Rocket Technology
基金
香江学者计划(XJ2023015)
国家自然科学基金(12202496)
中国博士后科学基金资助项目(2022M723866)
江苏省青年基金(BK20210435)。
关键词
药柱
裂纹扩展
有限元
点火压力
propellant grain
crack propagation
finite element method
ignition pressure
