钢筋混凝土T梁桥在爆炸载荷下的损伤研究

Damage study of reinforced concrete T-beam bridge subjected to blasting loads

通过制作钢筋混凝土T梁桥缩尺模型,将压电智能骨料内置于钢筋混凝土T梁桥面板中.在桥面施加多次爆炸荷载,采用压电主动传感技术获得每次爆炸试验后的压电能量值,经过小波信号分析得到与混凝土材料损伤程度所对应的损伤指数.试验结果表明,该方法可以很好地监控钢筋混凝土桥梁内部的损伤发展情况,而所得损伤指数的变化可以用来评估T梁桥的破坏状态.结合LS/DYNA数值模拟软件对T梁桥在爆炸载荷下的破坏模式做进一步研究.数值计算的结果进一步验证了损伤指数的有效性,并发现钢筋混凝土T梁桥在爆炸载荷下主要产生纵向裂纹,可以合理增加箍筋的配筋率以减少其纵向裂纹的产生,提高钢筋混凝土T梁桥的抗爆性能.

A reduced scale reinforced concrete T-type beam bridge has been built embedded with piezoceramic smart aggregates(SAs).The blasting loads are applied to the deck;and the active sensing approach is used to obtain the wave energy after every loading;while the wavelet analysis method is applied to get the damage index corresponding to the damage level of the concrete material.The experiment results show that the approach can effectively detect the damage development in the concrete of the bridge;and the damage index can evaluate the damage situation of the T-beam bridge.Furthermore,LS/DYNA is used to simulate the destruction mode of the T-beam bridge under blasting loads.The results of the simulation confirm the effectiveness of the damage index;there are much more cracks extend in the longitudinal direction of the RC T-beam bridge,which means the reinforcement ratio of stirrups should be reasonably increased to reduce the development of longitudinal cracks and improve the capacity of explosion resistance of the RC T-beam bridge.