高强钢组合偏心支撑钢框架抗震性能与震后修复研究

发布时间：2018-06-07 12:58

本文选题：高强钢 + 耗能梁段　；参考：《西安建筑科技大学》2014年博士论文

【摘要】：普通偏心支撑钢框架设计时，需要放大梁柱内力以抵抗耗能梁段的应变硬化效应，导致用钢量增大和节点连接困难。为解决这一问题，根据“强弱相对”的抗震思路，将高强钢引入偏心支撑钢框架的梁、柱、支撑部分而耗能梁段采用低屈服点钢材，形成高强钢组合偏心支撑钢框架，旨在保证结构有良好抗震性能前提下降低用钢量，提高经济效益。本文通过模型试验、数值模拟和理论分析对这种新型结构的抗震性能进行研究，主要内容如下：（1）对1/2缩尺的K形和Y形平面试件进行4个单调加载试验和4循环加载试验，研究其主要抗震性能指标和破坏机理。结果表明剪切屈服型高强钢组合K形偏心支撑钢框架的抗震性能较好；Y形耗能梁段的屈服机制随着侧移增大逐渐由剪切型向剪-弯混合型转变；Y形梁段不宜过长，否则可能导致框架梁首先破坏；K形试件的破坏主要集中于耗能梁段，框架基本处于弹性状态，有利于震后修复。（2）在试验的基础上，采用ANSYS软件对影响试件抗震性能的参数进行有限元分析，同时考虑材料非线性和几何非线性。结果表明K形和Y形偏心支撑中框架和耗能梁段钢材的名义屈服强度比值为1.3时，承载力提高，耗能能力不下降；该比值为2.0时，，极限承载力显著提高，但耗能能力下降较多。（3）对于K形偏心支撑，耗能梁段长度对初始刚度、极限承载力和耗能能力影响较大；对于剪切屈服型，在耗能梁段相同、应力比相近的条件下，高强钢组合偏心支撑框架的抗震性能与Q345普通偏心支撑框架相当，而用钢量减少约14%。对于Y形偏心支撑，耗能梁段长度对初始刚度和破坏模式影响较大，对极限承载力和耗能能力影响较小；对于剪切屈服型，同样条件下，高强钢组合偏心支撑框架的抗震性能与Q345普通偏心支撑框架相当，而用钢量减少约16%。（4）采用耗能梁段替换法对剪切型高强钢组合K形偏心支撑钢框架进行震后修复，循环加载试验研究表明，修复后试件的极限承载力与原试件基本相同，同位移时的耗能能力相当。这种修复方法的工作量小，有利于震后快速恢复正常。（5）根据试验曲线建立K形、Y形高强钢组合偏心支撑框架的双线性恢复力模型，模型与骨架曲线基本相符；采用刚塑性机构法推导出K形、Y形试件的极限承载力公式，公式计算结果与试验和有限元的结果吻合较好，可配合恢复力模型使用。
[Abstract]:In the design of general eccentrically braced steel frame, it is necessary to enlarge the internal force of Liang Zhu to resist the strain hardening effect of energy dissipation beam section, which leads to the increase of steel content and the difficulty of joint connection. In order to solve this problem, according to the aseismic thought of "strong and weak relative", the high strength steel is introduced into the beam, column and energy consuming beam section of eccentrically braced steel frame, and the low yield point steel is used in the beam section of the eccentrically braced steel frame to form the high strength steel composite eccentrically braced steel frame. The purpose of this paper is to reduce the amount of steel used and improve the economic benefit under the premise of good seismic performance of the structure. In this paper, the seismic performance of this new structure is studied by model test, numerical simulation and theoretical analysis. The main contents are as follows: 1) four monotonic loading tests and four cyclic loading tests were carried out on K and Y plane specimens with 1 / 2 scale, and their main seismic performance indexes and failure mechanism were studied. The results show that the seismic behavior of shear yield steel composite K-shaped eccentrically braced steel frame is better. The yield mechanism of Y-shaped energy dissipation beam gradually changes from shear type to shear-bending type with the increase of lateral displacement. Otherwise, it may lead to the first failure of the frame beam and the damage of the K-shaped specimen is mainly concentrated in the energy dissipation beam section, and the frame is basically in an elastic state, which is beneficial to the post-earthquake repair. 2) on the basis of the experiment, the finite element analysis of the parameters affecting the seismic behavior of the specimen is carried out by using ANSYS software, and the material nonlinearity and geometric nonlinearity are considered at the same time. The results show that when the nominal yield strength ratio of K-shaped and Y-shaped eccentrically braced steel is 1.3, the bearing capacity increases, but the energy dissipation capacity does not decrease, and the ultimate bearing capacity increases significantly when the ratio is 2.0, but the energy dissipation capacity decreases significantly. For K eccentricity braces, the length of energy dissipation beam section has a great influence on initial stiffness, ultimate bearing capacity and energy dissipation capacity, and for shear yield type, under the condition of the same energy dissipation beam segment and similar stress ratio, The seismic behavior of high strength steel composite eccentrically braced frame is equivalent to that of Q345 general eccentric braced frame, while the steel content is reduced by about 14%. For Y-shaped eccentric braces, the length of energy-dissipation beam section has a great influence on initial stiffness and failure mode, but has little effect on ultimate bearing capacity and energy dissipation capacity, while for shear yield type, under the same conditions, The seismic behavior of high strength steel composite eccentrically braced frame is similar to that of Q345 general eccentric braced frame, but the steel content is reduced by about 16%. 4) the composite K-shaped eccentrically braced steel frame with shear type high strength steel is repaired by the replacement method of energy dissipation beam. The cyclic loading test results show that the ultimate bearing capacity of the repaired specimen is basically the same as that of the original specimen. The energy dissipation capacity is equal to that of displacement. The workload of this method is small, which is beneficial to the rapid recovery of normal after the earthquake. The bilinear restoring force model of K-shaped high-strength steel composite eccentrically braced frame is established according to the test curve, which is basically consistent with the skeleton curve, and the ultimate bearing capacity formula of K-shaped Y-shaped specimens is derived by using the rigid-plastic mechanism method. The results of the formula are in good agreement with the experimental and finite element results, and can be used with the restoring force model.
【学位授予单位】：西安建筑科技大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU391;TU352.1

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