摘要
首先进行了0、0.1fc、0.25fc和0.4fc四个不同初始定侧压级别下的混凝土三轴压静载试验和0.1fc、0.25fc两个不同初始定侧压级别下的混凝土三轴压等幅疲劳试验,疲劳试验中最小应力水平均为0.1fc,最大应力水平为1.6fc^2.5fc,根据混凝土三轴压本构特征得到其在不同加载工况下的疲劳寿命。然后利用等效疲劳寿命和等效应力水平的概念,通过三参数Fardis-Chen模型和修正的Aas-Jakobsen方程得到统一的S-N曲线方程,并以此得到混凝土在不同侧压工况下的疲劳强度,从而使混凝土多轴受压疲劳强度问题得到简化。
An experimental program is carried out to investigate the fatigue strength of concrete under multi-axial compressive cyclic loading. The specimens are subjected to constant-amplitude triaxial compressive cyclic loading, with the constant initial lateral load being equal to 0. 1fc or 0. 25fc. The lower limit of the cyclic stress is 0. 1fc and the upper limit ranges from 1.6fc to 2.5fc. Based on the triaxial constitutive characteristics of the concrete, the fatigue life is evaluated for various cyclic loading cases. The three-parameter Fardis-Chen model is calibrated against the static triaxial compression test results, so that the static strength under various lateral loadings can be calculated. Applying the concept of equivalent fatigue life and equivalent stress level, in order to simplify the issue, a unified S - N curve, i. e. , a modified Aas-Jakobsen equation is established to obtain the multi-axial fatigue strength.
出处
《土木工程学报》
EI
CSCD
北大核心
2005年第8期31-35,48,共6页
China Civil Engineering Journal
基金
国家自然科学基金资助项目(50078010)
关键词
混凝土
三轴压疲劳
疲劳强度
等效疲劳寿命
等效应力水平
concrete
triaxial compressive cyclic loading
fatigue strength
equivalent fatigue life
equivalent stress level
