基于不同冲击能量全轻混凝土梁落锤试验研究

Study of drop-weight test for all-light concrete beams under different impact energy

为探究不同冲击能量下全轻混凝土梁动态响应,进行全轻混凝土梁落锤试验及有限元模拟,详细分析破坏形态、冲击力时程曲线、跨中位移时程曲线及能量时程曲线。结果表明:冲击荷载作用下,梁跨中产生楔形斜裂缝,冲击点及底部跨中局部破坏严重;跨中位移时程曲线以逐渐衰减的正弦波形式运动;从能量变化角度分析,梁体内大部分动能转化为变形能,并以内能形式耗散;冲击能量提高63.3%,冲击力峰值及跨中最大位移分别提高了24.9%、56.6%。

The purpose of this research is to explore the dynamic response of all-light concrete beams under different impact energy.The drop-weight test and finite element analysis are carried out for 2 all-light concrete beams.Failure mode,time-history curve of impact force,time-history curve of mid-span displacement and time-history curve of energy are described in detail.The results obtained are as follows,under the impact load,wedge-shaped inclined crack occurs in the middle of beam span,and the local damage of concrete at the impact point and the middle of bottom span is serious.The time-history curve of mid-span displacement moves in the form of sine wave,which gradually attenuates.From the view of energy change,most of kinetic energy in the beam is transformed into deformation energy and dissipated in the form of internal energy.When the impact energy is increased by 63.3%,peak value of impact force and mid-span displacement are increased by 24.9% and 56.6% respectively.