【摘要】：性能化抗震設(shè)計的重要基礎(chǔ)是確定表征結(jié)構(gòu)抗震反應(yīng)的指標(biāo),合理的結(jié)構(gòu)反應(yīng)指標(biāo)能夠評價結(jié)構(gòu)在不同水準地震作用下的性能。同時,合理的結(jié)構(gòu)反應(yīng)指標(biāo)也能夠評價結(jié)構(gòu)的損傷程度,能夠作為決策者對結(jié)構(gòu)震后處理的決策依據(jù)。結(jié)構(gòu)的頻率、振型等動力特性是結(jié)構(gòu)本身的基本屬性,隨著地震荷載增強,結(jié)構(gòu)進入彈塑性階段,結(jié)構(gòu)構(gòu)件發(fā)生損傷時,結(jié)構(gòu)動力特性也在發(fā)生改變。因此,本文重點探討基于結(jié)構(gòu)動力特性改變的損傷參數(shù)。本文通過彈塑性靜力推覆過程中結(jié)構(gòu)動力特性的變化來進行結(jié)構(gòu)損傷評估,提出基于頻率下降率損傷指標(biāo)、考慮頻率余量的損傷指標(biāo)以及根據(jù)各階振型相對質(zhì)量計算的組合頻率損傷指標(biāo)�？紤]到當(dāng)前主流分析軟件無法得到彈塑性推覆過程中結(jié)構(gòu)的動力特性,本文對IDARC程序進行了改編,使之能夠輸出結(jié)構(gòu)靜力推覆過程中每一步的各階頻率及振型。本文建立了一10層框架模型,并取其中一榀進行分析。應(yīng)用改編IDARC程序,通過逐步增加水平力計算結(jié)構(gòu)響應(yīng),并在每步計算動力特性的改變,結(jié)果表明,結(jié)構(gòu)各階頻率在推覆過程中均會下降,但結(jié)構(gòu)低階振型變化較小。計算基于動力特性的損傷參數(shù)指標(biāo)的變化歷程,并與基于位移延性、基于Park-Ang模型等幾種損傷參數(shù)進行對比,發(fā)現(xiàn)基于動力特性的損傷參數(shù)能較好地識別結(jié)構(gòu)屈服階段和失效階段。本文提出的基于頻率的損傷指標(biāo)能夠反映結(jié)構(gòu)的整體破壞歷程,對結(jié)構(gòu)的各個階段較好的識別,提出的組合頻率損傷指標(biāo)一定程度上能夠綜合反映前幾階振型對損傷的貢獻。本文通過考察結(jié)構(gòu)推覆全過程中動力特性變化這一視角,并計算相應(yīng)的頻率損傷指標(biāo),對結(jié)構(gòu)的破壞歷程和損傷表征方法進行了綜合研究,為結(jié)構(gòu)的整體損傷評估提供了新的途徑。
[Abstract]:The important foundation of performance-based seismic design is to determine the index of seismic response of structure, and reasonable structural response index can evaluate the performance of structure under different earthquake levels. At the same time, the reasonable structural response index can also evaluate the damage degree of the structure, and can be used as the decision basis of the decision maker for the post-earthquake treatment of the structure. The dynamic characteristics of structure, such as frequency and mode, are the basic properties of the structure itself. With the increase of seismic load, the structure enters the elastic-plastic stage, and the dynamic characteristics of the structure also change when the structural members are damaged. Therefore, the damage parameters based on the dynamic characteristics of the structure are discussed in this paper. In this paper, the structural damage assessment is carried out through the change of the dynamic characteristics of the structure during the elastoplastic static force push-over process, and the damage index based on the frequency drop rate is proposed. The damage index of frequency margin and the combined frequency damage index calculated according to the relative mass of various modes are considered. Considering that the current mainstream analysis software can not obtain the dynamic characteristics of the structure in the process of elastoplastic nappe, the IDARC program is adapted to output the frequencies and modes of each step in the static push process of the structure. In this paper, a 10-story frame model is established and one of them is analyzed. By adapting the IDARC program, the structural response is calculated by increasing the horizontal force step by step, and the change of the dynamic characteristics is calculated at each step. The results show that the frequency of each order of the structure will decrease in the process of nappe, but the change of the low-order mode of the structure will be small. The change history of damage parameters based on dynamic characteristics is calculated and compared with several damage parameters based on displacement ductility and Park-Ang model. It is found that the damage parameters based on dynamic characteristics can better identify the yield stage and failure stage of the structure. The damage index based on frequency presented in this paper can reflect the whole damage history of the structure, and better identify each stage of the structure. To some extent, the combined frequency damage index can reflect the contribution of the previous vibration modes to the damage to a certain extent. In this paper, the damage history and damage characterization method of the structure are comprehensively studied by examining the dynamic characteristics change during the whole process of the structure nappe, and calculating the corresponding frequency damage index. It provides a new approach for structural damage assessment.
【學(xué)位授予單位】：天津大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TU375.4;TU317

【引證文獻】

相關(guān)碩士學(xué)位論文 前1條

1 顧煒;鋼筋銹蝕對鋼筋混凝土結(jié)構(gòu)動力特性影響的試驗研究[D];山東大學(xué);2017年

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本文編號：2233393