摘要
本文提出了考虑物理非线性的钢筋混凝土杆系结构极限承载力高精度分析方法。在截面受力分析中,考虑了多种钢筋-混凝土间相互作用的本构关系及钢筋强化段的影响,引入连续变化的应变协调因子,以考虑截面裂缝展开后应变分布的非平截面性,用数值积分法通过截面的平衡搜索得到了适用于任意截面的M-φ-EI关系和N-ε-EA关系;在单元分析中,针对单元内各点刚度参差不齐的特点,用子结构法推导了新的单元刚度矩阵;最后用位移增量两步迭代法求解,得到了包括下降段在内的结构P-δ全过程曲线,12根试验梁的初步验证显示,本法效果良好。
In this paper, the moment--curvature relationship of reinforced concrete
section is solved according to actual stress--strain curves of reinforcement steel and
concrete. In view of the variety of constitutive law of steel--concrete interaction and
the strengthening behavior of the steel bar, a strain coordination factor variant in
succession is introduced to take into account the nonlinear strain distribution along
the height of cross section as crack is formed and spread. The moment--curvature
curves suitable for all types of cross--sections are obtained by using both numerical
integral method and balance search of the cross-section. To describe the nonlinear
variation of stiffness along the length of element, a new stiffness matrix is derived
with substructure method. Finally, the structure's full load--deflection curve, including
the failing branch, can be obtained with the two-step algorithm of incremental
displacement. The iteration processes of the method in all parts of the curve are
proved by the good agreement between measured and computed curves from twelve
model girder tests.
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
1993年第4期45-51,共7页
China Journal of Highway and Transport
关键词
结构
非线性
承载力
钢筋混凝土桥
Structure
Nonlinearity
Bearing capacity
Strain coordination factor
