Study on FE analysis of damage process due to fatigue loading and shear fatigue strength of RC members in water

钢筋混凝土构件水中疲劳荷载损伤过程及剪切疲劳强度有限元分析研究

基本信息

批准号：
11450166
负责人：
KAKUTA Yoshio
金额：
$ 4.86万
依托单位：
HOKKAIDO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

The followings are summary of what have been obtained in this research./FE analysis considering strength and stiffness reductions caused by damage due to fatigue loading can predict fatigue life of RC beams without stirrups. However the analysis cannot evaluate its deformation precisely because time-dependent deformation is not considered./Longitudinal strain and volumetric strain curve observed under compressive stress does not differ from different loading conditions./Longitudinal strain and Young's modulus curve observed under compressive stress does not differ from different loading conditions./Plastic strain in fatigue test increases as applied maximum force becomes greater./A constitutive model which can consider influence of loading speed was developed. The plastic strain in the model consists of plastic strain caused by cracks and creep strain. The model can be applicable to the both cases of static and fatigue loading./It was clarified through the numerical analysis using the proposed model that creep strain greatly affects fatigue life, fatigue strength predicted by the model is slightly greater than that calculated by an empirical equation and ultimate strain decreases linearly as stress at failure becomes smaller./In static test after fatigue test in water, shear force carried by stirrups in a RC beam increases as applied shear force increases but shear force carried by concrete does not because redistribution caused by compression failure in concrete compression zone takes place./To develop fatigue design method of RC members in water, not only fatigue strength of plain concrete but also shear resisting forces in truss mechanism in RC member must be quantified.

以下是这项研究中获得的摘要。/FE分析考虑到由于疲劳负荷而造成的强度和刚度降低，可以预测无ri刺的RC梁的疲劳寿命。但是，该分析无法确切地评估其变形，这是因为不考虑时间依赖性变形。在压缩应力下观察到在压力应力下观察到的量化应变曲线与不同的负载条件没有差异。/langudududinal菌株和Young的模量曲线在压缩应力下没有差异。从不同的负载条件中。疲劳测试中的塑性应变会随着施加的最大力变得更大而增加。/A构成模型可以考虑加载速度的影响。模型中的塑性应变由裂纹和蠕变应变引起的塑性应变。该模型可以适用于静态和疲劳负荷的两个病例。/通过数值分析使用所提出的模型来阐明IT，该模型极大地影响了疲劳寿命，该模型预测的疲劳强度略大于经验计算的。方程和最终应变会随着故障时的压力变小而线性减小。/in静态测试在水中疲劳测试后，rc骨在RC束中携带的剪切力会随着施加的剪切力增加而增加，但混凝土携带的剪切力并不是因为由重新分布引起的剪切力并不是因为/////nofe。为了开发水中RC成员的疲劳设计方法，不仅必须量化RC成员的疲劳强度，而且还必须量化RC成员中桁架机制中的剪切力。