混凝土Ⅰ－Ⅱ复合型断裂判据研究

本文基于混凝土Ⅰ－Ⅱ复合型断裂的试验研究，考虑到裂纹尖端混凝土双向受力时的破坏特征，提出了一个新的判断混凝土Ⅰ－Ⅱ复合型开裂的准则－复合应力准则。本文进行了一组偏直裂纹三点弯曲梁的试验，并用奇异元与等参元相结合的有限元法计算了裂纹失稳扩展时的应力强度因子ＫⅠ、ＫⅡ，采用试验结果确定了复合应力准则中的参数。与其它复合型断裂准则及国内试验结果的对比表明，本文提出的准则准确性好，适应性广。

STUDY OF Ⅰ-Ⅱ MIXED-MODE FRACTURE CRITERIA FOR CONCRETE

A new criterion (combined stress criterion) is presented for determining the mixed - mode fracture of concrete on the basis of experimental study. A series of mixedmode notched beam tests are performed to verify the Proposed criterion. The stress intensity factors K_Ⅰ and K_Ⅱ are computed by using strange element method. It is found that combined stress criterion has good crecision and adaptability comparing with other criteria.