PBL剪力连接件的疲劳试验与分析

为了研究PBL (Perfobond Leiste)这种新型剪力连接件的抗疲劳性能,基于深圳南山大桥剪力连接件的尺寸和要求,设计并制作了6个PBL剪力连接件的推出试件进行疲劳试验.试验在MTS815机器上进行,采用常幅正弦波荷载,加载频率为3 Hz,试验应力比为0.1.通过对试件进行常幅荷载的循环加载,观察试件中钢与混凝土块的相对滑移、连接件的破坏模式、疲劳寿命以及应变的特征等.试验结果表明：主要开裂方向为连接件底部斜向下呈45°,裂缝的宽度同裂缝与竖向的夹角成反比；疲劳荷载作用时,PBL连接件的抗疲劳性能良好,孔径越大试件的疲劳寿命越长；试验从一定程度上说明腹板越厚和疲劳荷载幅值越小,滑移量的增长速度越慢,同时孔径越大和疲劳幅值越小,滑移量的增长速度也越慢.

Fatigue test and analysis of PBL shear connectors

In order to study the anti-fatigue performance of a new shear connector: Perfobond Leiste(PBL),six launched specimens with PBL shear connectors were designed and produced to be carried on the fatigue test according to dimension and requirements of the shear connector used in Nanshan bridge in Shenzhen.Experiments were done on MTS815 under constant amplitude sine wave with 3 Hz load frequency and 0.1 stress rate.Through applying to the specimens by a constant amplitude cyclic loading,the slip of the steel and concrete block in specimen,failure modes of shear connectors,fatigue life and characteristics of strain and so on were observed.The results show that: the direction of the main crack is at the bottom of the connector under the 45° diagonal,while the crack width and the angle of the crack with vertical is inversely proportional;Under fatigue loading,PBL connector has a good fatigue resistance,the larger aperture the longer the fatigue life of specimens;the test to a certained extent explains that the thicker webs and the smaller amplitude of fatigue loading,the slip grew more slowly;meanwhile,the larger aperture and the smaller amplitude fatigue loading,the slip grew more slowly too.