混凝土软化本构曲线形状对K_R阻力曲线的影响(Ⅱ)──混凝土软化本构曲线形状与K_R阻力曲线的试验研究

Influence of Shapes of Softening Traction-Separation Law of Concrete upon K_R-curve (Ⅱ) ——Experimental Study of Shape of Softening Traction-Separation Law of Concrete and K_R-curve

基于虚拟裂缝扩展粘聚力的新KR 阻力曲线———KR(Δa) ,是较好地描述混凝土断裂全过程的裂缝扩展阻力曲线 .通过简便的试验和基于虚拟裂缝扩展粘聚力的解析方法 ,就可计算KR(Δa) .结合我们新近进行的断裂试验 ,得到了与实测结果相符的双线性软化本构曲线形状 ,把采用它和采用其他软化本构曲线形状计算的KR(Δa)相比较 .结果表明 ,选择合理的软化本构曲线形状 ,将得到合理的KR(Δa) .

WT5BZ]Based on the cohesive force acted on the fictitious crack zone, the new K R _curve (called K R (Δ a )) is a kind of crack propagation resistance curve which can better describes the crack propagation of concrete during the complete process of fracture. The K R( Δ a ) can be determined using a simple experimental method combining with an analytically evaluating method based on the cohesive force. To compare with the experimental results which are gained by our research team, reasonable shape of the bilinear softening traction_separation law are obtained. The K R( Δ a ) calculated by the reasonable shape is compared with those by the other shapes. The result shows that the reasonable K R( Δ a ) can be determined with the reasonable shape of the softening traction_separation law.