摘要
将动态焦散线法与高速摄影技术相结合,本文记录了高分子材料悬臂梁内裂纹扩展加速、减速过程。一方面,利用动态焦散线可确定扩展裂尖的瞬态应力强度因子;另一方面,利用最小二乘法将裂纹扩展的水平、垂直位移分量拟合成时间(t)的四次多项式,描述了裂纹扩展方向、裂纹扩展加速度以及裂纹扩展加速度与动态应力强度因子的关系。结果表明:裂纹扩展加速度与动态应力强度因子之间存在一定的依赖关系;利用最小二乘法将裂纹扩展的水平、垂直分量拟合成时间(t)的四次多项式,可以对裂纹的扩展方向、加速度进行定量分析。
The procedure of the crack acceleration and deceleration in a cantilever beam is seized with the help of high-speed photography, and the dynamic stress intensity factors near the crack tip are determined by dynamic caustic patterns. By means of the data processing of least square filing both the horizontal and vertical displacement components, the tip positions and the curving directions of the crack are obtained, which show the history of the acceleration of the crack moving. The results indicate the dependent relations between dynamic stress intensity factors and crack accelerations.
出处
《工程力学》
EI
CSCD
1996年第3期33-39,共7页
Engineering Mechanics
基金
国家教委跨世纪人才计划项目
国家自然科学基金项目资助
关键词
动态焦散线
瞬态
应力强度因子
裂纹扩展
dynamic caustics,stress intensity factors,crack acceleration and curving
