近海大气环境下锈蚀平面钢框架抗震性能试验研究及有限元分析

为研究近海大气环境下锈蚀钢框架结构的抗震性能，采用人工气候加速腐蚀技术对42件钢材材性试件和4榀平面钢框架进行加速腐蚀试验，然后对不同锈蚀程度的钢材材性试件进行拉伸破坏试验，获得锈蚀Q235B钢材力学性能指标（屈服强度、极限强度、伸长率和弹性模量）与其失重率的函数关系。并对4榀平面钢框架进行低周往复加载试验，研究了锈蚀对平面钢框架的破坏机制、滞回曲线、骨架曲线、刚度退化、延性及耗能能力等的影响。结果表明:4榀平面钢框架试件均发生了延性较好的破坏，呈现出混合屈服机制；但随着锈蚀程度的增加，试件承载力、耗能能力显著降低，强度和刚度退化明显，延性变差。在试验研究的基础上，利用通用软件ABAQUS对试验平面钢框架进行了非线性有限元分析，研究了轴压比对其力学性能的影响，结果表明:随着轴压比的增大，试件承载力、延性不断降低。

EXPERIMENTAL RESEARCH AND FINITE ELEMENT ANALYSIS ON THE SEISMIC BEHAVIOR OF CORRODED PLANE STEEL FRAMES UNDER OFFSHORE ATMOSPHERIC ENVIRONMENT

In order to study the seismic behavior of corroded steel frames under offshore atmospheric environment, accelerated corrosion tests on 42 tensile coupons and 4 plane steel frames were implemented by the technique of artificial climate accelerated corrosion. Tensile tests were then performed to obtain the functional relationships between mechanical properties (including yield strength, ultimate strength, elongation and elastic modulus) and weight loss rate for Q235B steel subjected to corrosion. 4 plane steel frames were tested under lateral low cyclic loading. The effects of corrosion degrees on the failure mechanism, hysteretic behavior, skeleton curves, stiffness degradation, ductility and energy dissipation capacity of the specimens were analyzed. The test results show that all specimens exhibit ductile failure with a hybrid yield dissipation mechanism. While the corrosion degree increases, the load bearing capacity and energy dissipation capacity decrease significantly, the strength and stiffness degrade obviously, and the ductility is reduced. Based on the experimental study, nonlinear finite element analyses were conducted on the test plane steel frames using ABAQUS. The influence of axial compression ratio on the mechanical properties of specimens were analyzed. The results indicate that with the increase of the axial compression ratio, the bearing capacity and ductility decrease monotonically.