方套圆中空夹层钢管混凝土组合构件#br# 横向撞击试验研究

通过对8个大空心率下方套圆中空夹层钢管混凝土组合构件进行横向撞击试验，研究试件的撞击受力过程、破坏形态、撞击力时程曲线特征、跨中挠度与测点纵向应变发展过程等。考察落锤撞击高度、边界约束和轴压比等关键因素对方套圆中空夹层钢管混凝土组合构件在横向撞击作用下动力响应的影响规律。试验研究结果表明：中空率为069的方套圆中空夹层钢管混凝土组合构件在横向撞击作用下主要发生显著地局部凹陷变形，而试件整体变形不显著；在试验研究参数范围内，随着落锤撞击高度的增大，试件局部凹陷程度、跨中残余挠度以及撞击持续时间均保持线性增长；边界约束对跨中残余挠度、撞击力平台值以及撞击持续时间有较大影响；轴压比是影响试件动力响应过程的重要因素，随着轴压比的增大，撞击力时程曲线的平台段会逐渐缩短并消失，跨中挠度变形速度变快，撞击进程加快。

Experimental study on circular-in-square concrete filled double-skin steel #br# tubular (CFDST) composite components under lateral impact

8 specimens of circular-in-square concrete filled double skin steel tubular (CFDST) with large hollow ratio were tested under the lateral impactThe impact process, failure modes of the specimens, time history of the impact force, lateral deformations and longitudinal strains were analyzed based on the experimental resultsThe effects of the impact height, boundary condition and axial load ratio on the dynamic response of circular in square CFDST composite components under lateral impact were consideredThe test results show that obvious local deformation at the impact location of the circular in square CFDST composite components with the hollow ratio of 069 can be observed and the global bending deformation is not significantWithin the experimental parameters scope, with the increase of impact height, local deformation at the impact location, residual lateral deformation at mid span and the impact duration time increase linearlyBoundary condition has a significant effect on the residual lateral deformation at the mid span, the plateau values of the impact force and the impact duration timeAxial load ratio is an important factor affecting the dynamic response of specimensWith the increase of the axial load ratio, the plateau values of the impact force gradually shorten and disappear, the deformation speed of lateral deformation at mid span becomes faster and the impact process also becomes more faster.