中文摘要：

能准确描述混凝土破坏过程的材料模型,对认识各类荷载条件下混凝土结构整体及细部响应问题上可起到关键性的作用,且通过对已验证其可靠性的有限元模型进行不同参数或工况分析能够建立相应的设计准则.LSDYNA显式算法的K＆C局部损伤混凝土模型是目前混凝土模型中能够考虑混凝土的断裂带宽度、断裂能及应变率对混凝土材性影响的模型之一.运用该局部损伤混凝土模型的有限元试算方案可被用于进行其它混凝土模型的参数校准.基于该局部损伤混凝土模型,针对有限元模型模拟中混凝土的断裂损伤及网格收敛性等问题展开了讨论,并完成混凝土单向抗拉和抗压模态的有限元试算.参考混凝土第1模态（Mode I）的断裂能及断裂带宽度,探讨了在受压情况下混凝土的局部损伤问题.在综合考虑了混凝土的拉压两态的材性指标影响的前提下,模拟了混凝土梁冲击试验并与试验结果进行了比较.

英文摘要：

This paper presents a study on concrete fracture and the associated mesh sensitivity using the finite element （FE） method with a local concrete model in both tension （Mode I） and compression.To enable the incorporation of dynamic loading,the FE model is developed using a transient dynamic analysis code LS-DYNA Explieit.A series of investigations have been conducted on typical fracture scenarios to evaluate the model performances and calibration of relevant parameters.The K＆C damage model was adopted because it is a comprehensive local concrete model which allows the user to change the crack band width, fracture energy and rate dependency of the material.Compressive localisation modelling in numerical modelling is also discussed in detail in rela- tion to localisation.An impact test specimen is modelled.