混凝土Lattice模型参数修正及钢筋混凝土锈胀破坏模拟

发布时间：2018-12-18 12:34

【摘要】：为了提高混凝土Lattice模型的计算精度,研究了模型参数修正方法.首先,对比分析了根据Lattice模型与实体模型计算得到的位移与应力,发现单一材料模型中位移比和应力比关联参数均与微单元特征长度成线性关系.其次,提出了一种递进式参数修正方法,即对微杆单元横截面面积和弹性模量依次进行修正.然后,采用多参数同步修正的方法,进一步修正了三相混凝土Lattice模型,修正后模型的位移和应力计算误差均不超过5%.基于该修正模型,模拟分析了钢筋混凝土结构的锈胀破坏过程.结果表明,角筋锈胀会引起竖向和水平向裂纹的共同发展,直至贯穿保护层.锈蚀钢筋间净距显著影响裂纹扩展模式;当净距与保护层厚度相当时,易形成钢筋间水平方向上的主裂纹,且主裂纹对其余方向的裂纹具有一定的抑制作用.
[Abstract]:In order to improve the calculation accuracy of concrete Lattice model, the method of model parameter modification is studied. First, the displacement and stress calculated by Lattice model and solid model are compared and analyzed. It is found that the correlation parameters of displacement ratio and stress ratio are linearly related to the characteristic length of microelement in a single material model. Secondly, a progressive parameter correction method is proposed, that is, the cross section area and elastic modulus of microbar element are corrected successively. Then, the three-phase concrete Lattice model is further modified by the method of multi-parameter synchronous correction. The displacement and stress calculation errors of the modified model are less than 5. Based on the modified model, the corrosion damage process of reinforced concrete structures is simulated and analyzed. The results show that both vertical and horizontal cracks will develop together, even through the protective layer. The net distance between corroded steel bars has a significant effect on the crack propagation mode, and when the net distance is equal to the thickness of the cover, the main crack in the horizontal direction between the steel bars is easy to form, and the main crack has a certain inhibition effect on the cracks in the other directions.
【作者单位】：东南大学江苏省高校工程力学分析重点实验室;
【基金】：国家自然科学基金资助项目(51478108;51578142)
【分类号】：TU528.571

【共引文献】