混凝土预制缺口梁试件拉张破裂数值模拟  

Numerical Simulation of Fracture with Prefabricated Concrete Notched Beam Specimens

作　　者：王来贵[1] 初影[1] 赵娜[2] 曹彦彦[1] 

机构地区：[1]辽宁工程技术大学力学与工程学院,辽宁阜新123000 [2]辽宁工程技术大学矿业技术学院,辽宁葫芦岛125105

出　　处：《沈阳建筑大学学报（自然科学版）》2009年第6期1100-1104,共5页Journal of Shenyang Jianzhu University：Natural Science

基　　金：国家自然科学基金重点项目(50434020);地质灾害防治与地质环境保护国家重点实验室开放基金项目(DZJK-0809)

摘　　要：目的针对混凝土抗压不抗拉的特性,探讨混凝土预制缺口梁断裂过程中裂纹尖端应力分布及裂纹扩展规律.方法采用拉张破裂有限元软件,对预制缺口在梁的顶部和在底部不同位置的模型进行数值模拟,描述拉张破裂后形成的不连续面.结果得出了不同方案中预制梁受拉破裂的破坏形式.缺口到梁跨度中心线的距离越小,梁试件底部拉应力区域越小;缺口到梁跨度中心线的距离越大,梁试件底部的拉应力区域越大.结论由不同方案破坏形式可以看出,缺口梁受拉应力作用发生破裂,形成不连续面;随着破裂面的形成与发展,混凝土梁的结构形式发生相应改变,导致应力状态随之调整.缺口的位置直接影响梁结构的破裂方式,缺口到梁跨度中心线的距离在一定的范围内,缺口控制着梁破坏的形式,破裂沿缺口发展;超出范围以后,缺口的存在不影响梁的破坏形式,破裂的形成、发展形式与无缺口梁的破坏形式相同.According to the problem that the concrete has low tensile strength propertys, this study aims at investigating the distribution and extended rules of the stress at the crack tip. The study adopted the software of finite element to simulate rock tension fracture, selected prefabricated notched specimens with different position as the simulation models, obtained the tension fracture forms of different projects. The short the distance from notched to the center line of beam span, the smaller the tension stress region at the bottom of beam specimen. The long the distance from notched to the center line of beam span, the greater the tensile stress region at the bottom of beam. Through the failure form of the different projects, it shows that the tensile stress make notched beam fracture to form a discontinuous surface;with the continuous formation and growth of rupture surface ,the structure of beams corresponding changes in stress state lead to be adjusted;the position of notch affected the rupture pattern of notched beam, the distance from notched to the center line of beam span in a certain range, the development of rupture along the notch; beyond the range, the existence of the notch does not affect the form of beam damage, the formation and development of the destruction form is the same as without notch beam＇s.

关 键 词：混凝土 拉张破裂 数值模拟 裂纹 拉应力 

分 类 号：TU375.1[建筑科学—结构工程]