论文部分内容阅读
利用试验观察和数值计算结果,首次对Drucker-Prager混凝土塑性模型预测约束混凝土性能的能力进行评估。评估结果显示,D-P塑性模型可成功预测FRP-约束及其他被动约束混凝土的性能,但必须进行修正使其具备如下3个特点:a.考虑三维应力的屈服准则。b.基于约束压力的硬化/软化准则。c.不仅取决于约束压力,且取决于约束压力的增长速度。目前的D-P模型均不包括上述3个特点,因此,无论是对主动约束还是被动约束(FRP约束),采用此模型都不能精确预测混凝土的性能。随后提出包括上述3个特点的D-P修正模型。采用所提模型对主动约束和被动约束混凝土性能进行数值预测,并与试验结果进行对比,两者基本吻合。最后,分析了所提塑性模型的局限性,这些问题将在相关论文的改进塑性破坏模型中进行探讨。
The experimental and numerical results are used to evaluate the ability of Drucker-Prager concrete plastic model to predict the behavior of concrete. The evaluation results show that the D-P plasticity model can successfully predict the performance of FRP-constrained and other passive confined concrete, but must be modified to have the following three characteristics: a. The yield criterion considering three-dimensional stress. b. Hardening / softening criteria based on restraint pressure. c. Not only depends on the pressure of restraint, but also on the rate of restraint. The current D-P model does not include the above three characteristics, therefore, whether it is for active or passive constraints (FRP constraints), using this model can not accurately predict the performance of concrete. Then the D-P correction model including the above three features is proposed. The proposed model is used to numerically predict the performance of the active and passive constrained concrete, and the results are compared with the experimental results. Finally, the limitations of the proposed plasticity model are analyzed. These problems will be discussed in the improved plastic failure model of the related paper.