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

点击翻译按钮获取中文摘要

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.