摘要
针对几何缺陷圆弧拱的面内非线性弹性失稳,利用自行设计的位移加载装置进行了实验研究,实时测量了圆弧拱在加载全过程的力-位移曲线,并跟踪了圆弧拱的实时变形情况和失稳模态,获得了圆弧拱的失稳平衡路径、缺陷圆弧拱的失稳上极值点和下极值点。将实验结果与理想状态拱的有限元数值计算结果进行了比较,揭示了圆弧拱矢跨比、初始几何缺陷对拱失稳极值点和失稳模态的影响。研究表明:1)初始几何缺陷影响了拱的荷载位移曲线,使得上极值点和下极值点偏离了理想曲线;2)初始几何缺陷使得圆弧拱在不稳定平衡路径中呈现出反对称变形趋势;3)随着矢跨比的增加,圆弧拱的前屈曲失稳临界荷载逐渐增大,结构的承载能力随之提高;4)初始几何缺陷对拱的前屈曲失稳模态的影响较后屈曲失稳模态大。
According to the in-plane nonlinear elastic instability of circular arch with initial geometrical defects,the displacement loading device is designed to measure real-time loading-displacement curves in the loading process.And the actual deformations and unstable modes of circular arch are tracked,further,the buckling equilibrium path of circular is obtained,by which the up and lower instability limit points are captured.By comparing the measurement results with the FEA results,it can be revealed that how the span ratio and the defects of arch influence the instability limit points and unstable mode.It is showed that:1)The initial geometric defects will influence the load-displacement curves of the arch,which makes the upper and lower limit stability points deviate from the ideal curves;2)Due to the initial geometric defect,the anti-symmetric deformation trend occurs in the unstable equilibrium path;3)With the increase of the ratio span,the instability limit load will improve,then the bearing capacity of the structure will enhance according;4)The effect of initial geometric defects on the pre buckling mode is more obvious than the post buckling mode.
作者
尹宸哲
禹奇才
刘爱荣
卢汉文
张骏峰
YIN Chenzhe;YU Qicai;LIU Airong;LU Hanwen;ZHANG Junfeng(Guangzhou University-Tamkang University Joint Research Center for Engineering Structure Disaster Prevention and Control,Guangzhou 510006,China)
出处
《中山大学学报（自然科学版）》
CAS
CSCD
北大核心
2018年第2期87-93,共7页
Acta Scientiarum Naturalium Universitatis Sunyatseni
基金
国家自然科学基金(51378133)
广东省科技计划项目(2016B050501004)
羊城学者首席科学家项目(1201541551)
关键词
圆弧拱
缺陷
面内失稳
非线性
集中力
circular arches
initial geometrical defects
in-plane instability
non-linear
concentrated load
