【摘要】 本文采用课题组已取得的实验研究结果 ,观测混凝土断裂全过程中基于粘聚力的新KR 阻力曲线的尺寸效应问题 .首先确定反映混凝土软化特性的软化本构曲线形状 ,对于简单实用的双线性软化本构曲线而言 ,取其拐点横坐标值为临界裂缝尖端张开位移 ,并引入一个直接影响混凝土软化本构曲线形状的参量λ ,结合实验结果 ,调整λ ,便得到用于计算新KR 阻力曲线的与实测结果相符的软化本构曲线形状 .结果表明 ,所获得的新KR 阻力曲线没有尺寸效应更多还原

【Abstract】 The influence of specimen size upon the new crack extension resistance curve ( K R curve), based on the cohesive force of concrete, in the process of fracture is studied according to the experimental results. The shape of softening traction separation law must be determined which can reflect the softening property of concrete. With regard to the bilinear softening traction separation law, by which the coordinate on X axis of the breaking point is equal to the critical crack tip opening displacement, a parameter named λ which directly affect the shape of softening traction separation law is introduced. The shape of softening traction separation law for estimation of the new crack extension resistance curve can be obtained by means of adapting λ to the experimental results. It can be seen that the new K R curve does not have size effect.更多还原