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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.
In order to improve the calculation accuracy of Lattice model, the model parameter correction method is studied.Firstly, the displacements and stresses calculated by Lattice model and solid model are comparatively analyzed. It is found that the correlation parameters of displacement ratio and stress ratio in the single material model are related to the micro-unit Linear relationship between characteristic length and length.Secondly, a method of progressive parameter correction is proposed, which is to correct the cross-sectional area and elastic modulus of micro-rod unit in turn.Then, using the multi-parameter synchronous correction method, According to the modified model, the failure process of the corrosion of reinforced concrete structures is simulated and analyzed.The results show that the corrosion of corroded tendons causes vertical and horizontal The common development of the cracks until the protective layer is crossed.The clearance between the corroded steel bars significantly affects the crack propagation mode.When the clearance distance is equal to the thickness of the protective layer, the main cracks in the horizontal direction between the steel bars tend to form, and the cracks in the other directions Has a certain inhibitory effect.