中心裂纹混凝土板的裂纹扩展和延迟失稳

THE EARLY STAGE PROPAGATION AND DELAYED INSTABILITY OF CRACK IN CONCRETE

本文把混凝土看作是具有损坏区的粘弹性材料,并结合裂纹前缘破坏过程的观测资料,提出了带裂纹的混凝土和破坏模型,研究了混凝土裂纹的早期扩展和延迟失稳问题。用本文给出的理论,较好地解释了在工程实际中所观察到的,以及大量实验所证实了的混凝土的早期裂纹扩展问题,并与实验数据符合较好。因此,对预测长期持续载荷作用下混凝土结构的安全性具有实际的意义。

This paper provides afailure model of the crack tip from the fact that the concrete presents visible viscoelastic under the long-time and continuous action of load,and accord- ing to the date given by modern examing and observing techniques for tensined concrete samples having a notch.The general laws have thus been researched for the early stage propagation and delayed instability of cracked conerete by the action of long-time and sus- tained load.Therefor,it is of practicle signicance to predict the service life of delayed crack instability for the concrete strctures during long period operation.