戚靖骅, 张振南, 葛修润. 基于拓展虚内键本构模型的多裂纹混凝土结构破坏分析[J]. 工程力学, 2014, 31(4): 54-60. DOI: 10.6052/j.issn.1000-4750.2012.10.0797
引用本文: 戚靖骅, 张振南, 葛修润. 基于拓展虚内键本构模型的多裂纹混凝土结构破坏分析[J]. 工程力学, 2014, 31(4): 54-60. DOI: 10.6052/j.issn.1000-4750.2012.10.0797
QI Jing-hua, ZHANG Zhen-nan, GE Xiu-run. ANALYSIS ON FAILURE OF CONCRETE STRUCTURE WITH MULTIPLE CRACKS BASED ON AUGMENTED VIRTUAL INTERNAL BOND METHOD[J]. Engineering Mechanics, 2014, 31(4): 54-60. DOI: 10.6052/j.issn.1000-4750.2012.10.0797
Citation: QI Jing-hua, ZHANG Zhen-nan, GE Xiu-run. ANALYSIS ON FAILURE OF CONCRETE STRUCTURE WITH MULTIPLE CRACKS BASED ON AUGMENTED VIRTUAL INTERNAL BOND METHOD[J]. Engineering Mechanics, 2014, 31(4): 54-60. DOI: 10.6052/j.issn.1000-4750.2012.10.0797

基于拓展虚内键本构模型的多裂纹混凝土结构破坏分析

ANALYSIS ON FAILURE OF CONCRETE STRUCTURE WITH MULTIPLE CRACKS BASED ON AUGMENTED VIRTUAL INTERNAL BOND METHOD

  • 摘要: 拓展虚内键(Augmented virtual internal bond, AVIB)是基于虚内键理论的一种多尺度本构模型,它同时考虑了微观虚内键的法向和切向变形,应用Xu-Needleman势函数描述虚内键,并在微观势函数基础上直接导出了宏观本构方程。由于脆性材料的抗压强度与微元体的应力状态有关,为了反映这种微元应力效应,依据混凝土三轴抗压强度准则定义了应力效应系数,并将其反映到AVIB本构模型中。对于已有裂纹,采用无厚度单元劈裂法进行建模,避免了网格重划分问题和单独设置接触单元问题。结合AVIB模型与无厚度单元劈裂法,对多裂纹混凝土结构的破坏进行了模拟分析。结果表明,预制裂纹的长度不同,导致结构的主裂纹扩展方式不同。模拟所得的结构破坏模式及荷载-主裂纹口张开位移曲线与相关文献报道结果基本一致,表明了该方法的有效性。由于该文所采用的AVIB本构方程中已蕴涵了混凝土断裂能及三轴强度准则,因而在整个断裂模拟过程中,既避免了外部的断裂准则问题,同时又不需要网格重构及附加自由度,提高了计算效率,为大体积混凝土结构的破坏分析提供了一种简单的可行方法。

     

    Abstract: The Augmented virtual internal bond (AVIB) model is a multi-scale constitutive model based on the virtual internal bond (VIB) theory. It simultaneously accounts for the normal and shear deformation effects of micro bond through Xu-Needleman potential. The stress states of micro elements have significant influence on the compressive strength of brittle materials. In order to reflect the stress effect of micro element, a stress effect coefficient is firstly defined according to the strength criteria and then is introduced into AVIB constitutive model. To model the preexisting cracks, the element partition method (EPM) is used, avoiding the re-meshing and setting-up of contact element. The improved AVIB, combined with the EPM, is used to simulate the failure process of the concrete structure. The simulated results show that the structure’s failure mode and final deformation are critically dependent on the pre-existing crack length and distribution. The simulated load-CMOD curves of the crack and failure modes agree with the results reported in literatures, which suggests that the present method is validated. Since the present constitutive relation of AVIB contains the fracture energy and strength criterion, it simplifies the simulation of crack propagation, avoiding separate facture criterion and mesh reconstruction, etc. It provides an efficient and feasible method for the failure analysis of larger-scale concrete structures with multiple cracks.

     

/

返回文章
返回