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，该分析无法恰恰评估其变形，因为不考虑时间依赖性变形。/langududialnal ature atn prains./longudududialnal atnecrage。/longudududials应变和langudududaginal的模态曲线在压缩压力下观察到的压力不大，在压缩压力下观察到的载荷量更大，而在压缩的压力下，较大的载荷量会增加量的效力。/是开发的。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载荷的两个病例。/通过数值分析使用所提出的模型来阐明蠕变菌株极大地影响疲劳寿命，模型预测的疲劳强度稍大于经验方程而计算出的疲劳强度略大于经验方程和最终的压力，而随着失败的效果较小的压力测试。随着施加的剪切力的增加而增加，但是混凝土携带的剪切力并不是因为发生了由混凝土压缩区域的压缩故障引起的重新分布。//为了开发水中RC成员的疲劳设计方法，不仅必须量化RC成员中桁架机制中抗固定力的疲劳强度。