基于Bouc-Wen本构对桥墩滞回参数识别的研究

发布时间：2018-01-20 14:41

本文关键词： 滞回曲线 Bouc-Wen本构 Opensees 参数识别　出处：《苏州科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：桥梁抗震设计主要分两个思路:减隔震抗震设计和延性抗震设计。减隔震装置能够通过自身耗能,保护结构,更换方便,成本较低;对于高墩等减隔震装置效果不明显的非常规桥梁结构,延性抗震体系依然能收到很好的效果;对于支座处易产生反方向力,基层土不稳定或者是软土层地区,采用减隔震抗震体系效果不明显,延性抗震体系效果较好。延性体系中极为重要的一个环节就是研究墩柱的耗能性能。以某四跨混凝土连续梁桥中跨桥墩为原型,本文建立Opensees数值计算模型,并按照1:2.5的比例浇筑混凝土桥墩,做低周往复试验。以Bouc-Wen本构为参数识别的基础,通过对桥墩滞回特性的研究来描述桥梁的抗震性能。本文研究重点如下:(1)基于原有对结构滞回特性研究的片面性,本文引用光滑恢复力本构模型。以Opensees有限元软件为数值模拟平台,从桥梁延性抗震设计的角度分析结构抗震性能。引入Bouc-Wen本构模型,分析该本构各个控制参数的取值对整个滞回环所带来的影响,进而分析各参数在滞回曲线形状控制中的作用。整个过程通过在有限元分析软件Opensees中通过控制其他参数不变,改变其中一个参数的办法来分析其变化过程。(2)应用Opensees有限元软件建立某四跨钢筋混凝土连续梁桥模型,选择中间墩柱部分做低周往复试验,绘制出中间跨墩柱的墩顶力-位移曲线。再基于Bouc-Wen本构模型,采用遗传算法识别出原有力-位移滞回曲线的滞回特性参数。将所识别的参数带入原有数值模型中,得到新的识别曲线,把两曲线放置于同一图幅中,对比两滞回环吻合度。(3)结构滞回特性是结构自身本质属性,不因外界荷载产生改变。本文改变加载制度,同样得到低周往复试验分析曲线。再将规则一下曲线的参数识别结果带入规则二加载条件下,得到新的识别曲线,再把识别曲线与初始曲线放同一图幅试比较,再次比较滞回环的吻合度。(4)对物理试验中桥墩做低周往复,分别取出其弹性阶段、峰值阶段、承载力下降阶段以及破坏阶段,并识别各阶段滞回参数,分析各个参数在滞回曲线中的影响。(5)将Bouc-Wen本构模型引入物理试验,本文对桥墩在往复荷载作用下的滞回曲线进行参数识别,得出桥墩的滞回曲线形状控制参数即反应该桥墩物理模型真实的材料本构。通过作动器给相同模型施加一个地震作用,得到物理试验的滞回环。把同样的地震波与低周往复试验中的识别参数带入到数值模拟的桥墩模型中去,得到识别参数的数值模拟曲线。两条曲线进行最大承载力及曲线形状的对比,分析其特点。
[Abstract]:The seismic design of the two main ideas: the isolation of seismic design and seismic ductility design. Seismic isolation device through its own energy, protection structure, convenient replacement, low cost; for the unconventional bridge with high pier seismic isolation device effect is not obvious, the ductility seismic system still can get good effect; the bearing is easy to produce the opposite direction, the basic soil is unstable or soft soil area, the seismic isolation system, the effect is not obvious, good seismic ductility ductility system system. A very important aspect of energy dissipation is research of piers. In a span concrete continuous girder bridge piers for the prototype, Opensees numerical model is established in this paper, and according to the ratio of 1:2.5 concrete pier, do low cyclicloadingtest. Based on the Bouc-Wen constitutive parameter identification, the characteristics of the research lag back to the pier The seismic performance of the bridge. To describe the focus of this paper is as follows: (1) the original return characteristics to research the structure of the one sidedness of Hysteresis Based on the referenced in this article smooth restoring force constitutive model. The numerical simulation platform by the finite element software Opensees, the seismic performance analysis from ductility seismic design point of view. The introduction of Bouc-Wen constitutive model and analyze the effect of the constitutive control parameters all throughout the whole of the hysteresis loop, and then analyzes the parameter curve shape control in lag. The whole process through the control of other parameters in the finite element analysis software Opensees to analyze the change process of change, change a parameter which measures (2.) using Opensees finite element software to establish the model of a four span reinforced concrete continuous girder bridge, select the part of the middle pier low cyclicloadingtest, draw the middle span pier column pier force displacement curve. Then based on Bouc-Wen constitutive model, using genetic algorithm to identify the hysteretic curves of hysteretic characteristic parameters. The identified parameters into the original numerical model, and get the recognition curve of new, the two curves are placed on the same map, comparing the two hysteresis loop anastomosis (3) structure. Hysteretic characteristics of structure with its own nature, is not due to external load change. The change of loading system, also analysis curve of low cyclicloadingtest. Then the rules about curve parameter identification results into rule two loading conditions, a new identification curve, then the identification curve and the initial curve put in the same figure a comparison, fit again comparing the hysteresis loop. (4) do cycilc to physical test of bridge pier, were taken out the elastic stage, peak stage, capacity decline stage and failure stage, and each stage to identify the hysteretic parameters analysis The parameters in the effect of hysteresis curve in. (5) Bouc-Wen constitutive model is introduced in this paper through physical experiments, parameters identification of bridge pier under cyclic loading hysteretic curve, obtained the hysteretic curve shape control parameters that reflect actual material of the pier. The material constitutive model of actuator applying an earthquake to the same model, get the physical test of the hysteresis loop. The recognition parameters of seismic wave and low cyclic loading test of the same into the pier model for numerical simulation to numerical simulation curve parameters have been identified. Comparing the maximum bearing capacity and the curve shape of the two curves, analysis of its characteristics.

【学位授予单位】：苏州科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U442.55

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