航空学报 > 1990, Vol. 11 Issue (2): 87-92

在阶跃载荷作用下双悬臂梁模型动态特性的近似分析法

刘元镛, 李玉龙   

  1. 西北工业大学
  • 收稿日期:1988-02-02 修回日期:1900-01-01 出版日期:1990-02-25 发布日期:1990-02-25

AN APPROXIMATE ANALYSIS FOR CALCULATION OF DYNAMIC PROPERTIES FOR DCB MODEL UNDER STEP LOADING

Liu Yuanyong, Li Yulong   

  1. Northwestern ploytechnical University
  • Received:1988-02-02 Revised:1900-01-01 Online:1990-02-25 Published:1990-02-25

摘要: <正> 大量的研究表明:在冲击载荷的作用下,材料的机械性能和断裂韧性都会随着加载速率的变化而发生变化,断裂韧性随着加载速率的增高会明显下降。在动态起裂判据中,K_(Id)(?)是由动态试验来确定的,而K(?)(t)则要对结构进行完全的动态分析来确定。由于动态问题的复杂性,一般都借助于大规模的数值计算求解动态应力强度因子等动态特性。本文根据梁的振动特性,提出了一种简单的近似分析方法求解DCB模型在阶跃载荷作用下的动态响应、动态应力强度因子和动态能量释放率等特性,并提出一个用DCB模型测定K_(Id)(?)的简单方法。文中还使用八节点等参元进行了动态汁算,将有限元法计算的结果与近似法作了比较,两者吻合很好。

关键词: 阶跃载荷, DCB模型, 动态应力强度因子

Abstract: The dynamic properties of DCB model under step loading were calculated by using the vibration model of the beam. The fundamental frequency, the pin displacement, the external work, potential and kinetic energy, the dynamic stresss intensity factor and dynamic energy release rate were formulated approximately. Furthermore, a simple and available expression to determine the initial dynamic fracture toughness by using the DCB model is obtaind.

Key words: step load, DCB model, dynamic stress intensity factor