扩展准则对混凝土裂缝黏聚区特性的影响

The effect of propagation criterion on the properties of crack cohesive zone in concrete

以无限大平板中心拉伸裂缝模型为例,分别基于强度准则和韧度准则,利用级数展开法获得了断裂过程区特性。结果表明,不同裂缝扩展准则对黏聚区长度、裂缝张开位移及黏聚力分布均具有一定的影响。相比强度准则,采用韧度准则的临界黏聚区长度有所减小。临界黏聚区长度及裂缝张开位移均随韧度增大而逐渐减小,黏聚力随韧度增大而逐渐增大。

Taking the infinite plate model with a center crack under tensile for example,the characteristics of cohesive zone were obtained by polynomial series expansion method using the strength criterion and toughness criterion,respectively.The results show that the crack propagation criterion have considerable impact on the characteristics of cohesive zone,including the cohesive zone length,the crack opening displacement and the cohesive stress distribution.The results showed that the cohesive zone length calculated by toughness criterion is smaller than that by strength criterion.The critical cohesive zone length and crack opening displacement both decrease with the toughness,whereas the cohesive stress increases with the toughness.