利用无网格方法分析钢筋混凝土梁开裂问题 - Lu Xinzheng.PDF

第21 卷第2 期 工 程 力 学 Vol.21 No. 2 2004 年 4 月 ENGINEERING MECHANICS April 2004 文章编号：1000-4750(2004)02-0024-05 利用无网格方法分析钢筋混凝土梁开裂问题 陆新征，江见鲸 (清华大学土木工程系，北京 100084) 摘 要：裂缝处理一直是混凝土数值分析中的一个难点，而无网格方法由于不需要单元网格，非常适用于分析断 裂问题，因此可以考虑将其引入混凝土断裂分析领域。首先将混凝土中的裂缝分为微观裂缝和宏观裂缝，对于微 观裂缝仍然使用传统的弥散裂缝模型；而宏观裂缝则利用无网格方法可以非常方便地调整节点分布的特点，通过 增加裂缝节点和裂面边界的方法加以模拟。并给出了宏观裂缝产生，扩展的具体模拟方法。通过算例表明，利用 提出的方法，可以较准确地分析混凝土宏观裂缝的产生、扩展以及裂缝宽度变化，得到一些传统有限元方法难以 得到的计算结果。 关键词：断裂力学；混凝土裂缝；无网格；弥散裂缝；宏观裂缝 中图分类号：O346.1 文献标识码：A ANALYSIS OF CRACKING OF RC BEAMS USING MESHLESS METHOD LU Xin-zheng , JIANG Jian-jing (Department of Civil Engineering, Tsinghua University, Beijing 100084, China) Abstract: Simulation of cracking in concrete is difficult using traditional numerical method. The meshless method has been widely used in fracture analysis . In this paper, cracks in concrete are divided into micro-cracks and macro-cracks. Different crack models are applied to each kind of cracks, respectively. The micro-cracks are represented by the smeared crack model. The macro cracks are represented by addit ional nodes and edges, with the convenience of adjusting node distribution in meshless method. The details on the simulation of macro-cracks’ appearance and propagations are introduced. A numerical example shows that the present method can obtain the propagation of macro-cracks in concrete, together with the width of the cracks. Behavior which are intractable for the traditional finite element method, is observed. Key words: fracture mechanics; concrete crack; meshless; smeared crack; macro-crack 1 引言 否正确地分析混凝土结构的关键问题，同时，也是