摘要
采用非线性有限元软件BNLAS进行超大跨径CFRP主缆悬索桥与超大跨径钢主缆悬索桥的静动力特性对比分析,从加劲梁约束体系、主缆安全系数、主缆矢跨比、主缆弹性模量4个方面进行超大跨径CFRP主缆悬索桥合理结构体系研究。结果表明:采用CFRP做超大跨径悬索桥主缆可大幅提高主缆应力中活载应力百分比和自振频率,但活载挠度大幅增加;随着跨径增大,加劲梁约束体系对超大跨径悬索桥的动力特性影响减小,3跨连续漂浮体系作为超大跨径CFRP主缆悬索桥加劲梁的约束体系较优;增大主缆安全系数可提高结构的竖向刚度、竖弯基频和扭转基频,但对横向刚度和横弯基频基本无影响;减小矢跨比可提高结构的竖向和横向刚度以及竖弯基频和横弯基频,但会降低扭转基频;增大CFRP主缆的弹性模量可大幅减小活载竖向挠度,提高竖弯基频和扭转基频,但对横向刚度、横弯基频以及主缆线形和应力基本无影响。
BNLAS （Bridge NonLiner Analysis System） is a nonlinear finite element program. Using BNLAS, the differences between the super large-span suspension bridge with CFRP cables and the super large-span suspension bridge with steel cables were researched and the influences of the restraint systems of the stiffening girder, main cable safety factor, rise-span ratio and cable elastic modulus on the static and dynamic performances of the super large-span suspension bridge with CFRP cables were analyzed. J ne results show that after using CFRP, the percentage of live load stress in cables, the natural vibration frequency and the displacement of the stiffening girder caused by live load are increased significantly. With the increase of the span, the influence of the restraint systems of the stiffening girder on the dynamic char- acteristics of the super large＋span suspension bridge becomes smaller. 3-span continuous floating system is more favorable to be the restraint system of the stiffening girder for super large-span suspension bridge with CFRP cables. Increasing the safety factor of the main cable can improve structural vertical stiffness and the basic frequency of vertical bending and torsion, but affects little the structural lateral stiffness and the basic frequency of lateral bending. Decreasing the rise-span ratio can increase the structural stiffness and the basic frequency of vertical bending and lateral bending, but lower the basic frequency of torsion. Improving the CFRP cable elastic modulus can greatly decrease the vertical displacement of the stiffening girder caused by live load and increase the basic frequency of vertical bending and torsion, but affects little the structural lateral stiffness, the basic frequency of lateral bending and the shape and the stress of CFRP cable.
出处
《中国铁道科学》
EI
CAS
CSCD
北大核心
2011年第1期62-67,共6页
China Railway Science
基金
国家"八六三"计划项目(2008AA11Z101)
关键词
超大跨径悬索桥
结构体系
非线性有限元
CFRP主缆
Super large-span suspension bridge
Structure system
Nonlinear finite element
CFRP maincable
