本文選題：反分析 + 泄流結(jié)構(gòu)��； 參考：《南昌大學(xué)》2015年碩士論文

【摘要】：我國(guó)的高壩建設(shè)規(guī)模居世界首位,這些已(在)建的拱壩在壩高、泄流量和泄洪功率等方面已居世界領(lǐng)先水平。泄流結(jié)構(gòu)在宣泄洪水時(shí),由于強(qiáng)烈紊動(dòng)的水流往往具有很大的動(dòng)能,極易導(dǎo)致泄水結(jié)構(gòu)的劇烈振動(dòng)甚至結(jié)構(gòu)發(fā)生破壞。近年來(lái),高速泄洪水流誘發(fā)泄流結(jié)構(gòu)振動(dòng),從而影響工程運(yùn)行安全,嚴(yán)重時(shí)會(huì)導(dǎo)致破壞的實(shí)例屢見(jiàn)不鮮。研究發(fā)現(xiàn),泄流結(jié)構(gòu)破壞的原因主要包括兩個(gè)方面:結(jié)構(gòu)動(dòng)位移超過(guò)振動(dòng)安全標(biāo)準(zhǔn);結(jié)構(gòu)動(dòng)應(yīng)力響應(yīng)過(guò)大導(dǎo)致振動(dòng)疲勞破壞。因此,獲取流激振動(dòng)下的泄流結(jié)構(gòu)的動(dòng)位移值和動(dòng)應(yīng)力值,是評(píng)價(jià)泄流結(jié)構(gòu)能否正常工作的重要依據(jù)。對(duì)泄流結(jié)構(gòu)開(kāi)展原型振動(dòng)測(cè)試時(shí),由于實(shí)測(cè)動(dòng)力響應(yīng)點(diǎn)數(shù)量是有限的,難以全面反映整個(gè)結(jié)構(gòu)的振動(dòng)響應(yīng)特征,因此如何根據(jù)有限的實(shí)測(cè)點(diǎn),反饋出整個(gè)結(jié)構(gòu)的動(dòng)力響應(yīng),尤其是針對(duì)水下結(jié)構(gòu)的的動(dòng)應(yīng)力響應(yīng),進(jìn)而對(duì)泄流結(jié)構(gòu)運(yùn)行安全評(píng)價(jià)具有重要意義,也是本文研究的主要問(wèn)題,主要從以下三個(gè)方面展開(kāi)研究:(1)通過(guò)對(duì)導(dǎo)墻模型的數(shù)值模擬,驗(yàn)證反分析方法的可行性。由于誘發(fā)導(dǎo)墻振動(dòng)響應(yīng)的水動(dòng)力荷載是未知的,首先,本文以一典型水動(dòng)力荷載作為輸入,建立ANSYS有限元數(shù)值模型進(jìn)行瞬態(tài)分析,從中提取測(cè)點(diǎn)的動(dòng)位移響應(yīng)時(shí)程,將其作為反分析方法的已知條件;其次,將這些測(cè)點(diǎn)的動(dòng)位移響應(yīng)譜作為已知輸入,編制反分析基本程序,反演出誘發(fā)導(dǎo)墻振動(dòng)響應(yīng)的水動(dòng)力荷載,實(shí)現(xiàn)了振源的識(shí)別,并將該動(dòng)水荷載的實(shí)測(cè)值和計(jì)算值作對(duì)比,驗(yàn)證反分析方法的可行性;最后,再根據(jù)識(shí)別出的動(dòng)水荷載正分析計(jì)算整個(gè)導(dǎo)墻結(jié)構(gòu)的整體動(dòng)位移響應(yīng)均方根值,并進(jìn)行了對(duì)比驗(yàn)證,同時(shí)基于模態(tài)疊加法,反演出整個(gè)結(jié)構(gòu)的動(dòng)應(yīng)力響應(yīng)。反演結(jié)果與瞬態(tài)響應(yīng)計(jì)算結(jié)果對(duì)比表明,誤差均控制在5%以?xún)?nèi),驗(yàn)證了泄流結(jié)構(gòu)振動(dòng)響應(yīng)的反分析方法是有效而可行的。(2)開(kāi)展了基于有限測(cè)點(diǎn)的二灘拱壩原型動(dòng)態(tài)響應(yīng)場(chǎng)反演研究。以二灘拱壩原型工程為例,針對(duì)拱壩的六種不同泄水工況,開(kāi)展了動(dòng)位移振動(dòng)響應(yīng)測(cè)試,根據(jù)有限測(cè)點(diǎn)的動(dòng)位移實(shí)測(cè)結(jié)果,實(shí)現(xiàn)了整個(gè)壩體的動(dòng)位移場(chǎng)和動(dòng)應(yīng)力場(chǎng)的反演。通過(guò)每種工況下實(shí)測(cè)二灘拱壩B1~B7測(cè)點(diǎn)動(dòng)位移響應(yīng)時(shí)程,反分析拱壩泄流時(shí)所受三個(gè)等效動(dòng)水荷載,該過(guò)程引入遺傳算法,優(yōu)化了識(shí)別結(jié)果。基于反演出的三個(gè)等效荷載進(jìn)行正分析,計(jì)算出拱壩泄流時(shí)的整體動(dòng)位移場(chǎng),并與已知測(cè)點(diǎn)的動(dòng)位移響應(yīng)均方根進(jìn)行了對(duì)比驗(yàn)證�；谀B(tài)疊加法,對(duì)上述六個(gè)工況的拱壩原型結(jié)構(gòu)的整體動(dòng)應(yīng)力場(chǎng)進(jìn)行了反演,得出壩體的整體動(dòng)應(yīng)力,并對(duì)壩體應(yīng)力較大部位的動(dòng)應(yīng)力結(jié)果進(jìn)行了分析。反演結(jié)果表明:①拱壩同一高程拱圈上各節(jié)點(diǎn)動(dòng)位移響應(yīng)均方根值呈現(xiàn)“中間大,兩邊遞減”的變化趨勢(shì);②拱圈上的切向動(dòng)應(yīng)力響應(yīng)變化趨勢(shì)和動(dòng)位移響應(yīng)類(lèi)似;③拱冠梁上各節(jié)點(diǎn)的切向動(dòng)應(yīng)力均方根值隨高程的下降逐漸減小;豎向動(dòng)應(yīng)力均方根值隨高程的升高逐漸增加。(3)對(duì)現(xiàn)有的工程結(jié)構(gòu)振動(dòng)安全評(píng)價(jià)標(biāo)準(zhǔn)進(jìn)行了調(diào)研和整理分析,并結(jié)合二灘拱壩原型工程整體動(dòng)位移場(chǎng)和動(dòng)應(yīng)力場(chǎng)的反演結(jié)果,對(duì)二灘拱壩在該六種工況下的運(yùn)行安全進(jìn)行了評(píng)價(jià),結(jié)果表明,二灘拱壩在該六種工況下的泄洪振動(dòng)是安全的。
[Abstract]:The construction of high dam in China ranks first in the world, and the arch dams built in the world have been leading the world's leading level in the aspects of dam height, discharge and flood discharge power. In the case of flood discharge, the turbulent flow often has great kinetic energy, which can easily cause the violent vibration of the discharge structure and even the structure damage. In recent years, The high speed flood discharge flow induces the vibration of the discharge structure, which affects the safety of the engineering operation, and the serious cases which will cause damage occur frequently. It is found that the cause of the failure of the leakage structure mainly includes two aspects: the structural dynamic displacement exceeds the vibration safety standard; the structural dynamic stress response is too large to cause the vibration fatigue damage. Therefore, the flow induced vibration is obtained. The dynamic displacement value and the dynamic stress value of the moving discharge structure are the important basis for evaluating the normal work of the discharge structure. In the prototype vibration test of the discharge structure, it is difficult to fully reflect the vibration response characteristics of the whole structure because the number of the measured dynamic response points is limited. The dynamic response of the structure, especially in response to the dynamic stress response of underwater structure, is of great significance to the safety evaluation of the discharge structure. It is also the main problem in this paper. It is mainly studied in the following three aspects: (1) the feasibility of the inverse analysis method is verified by the numerical simulation of the guide wall model. The hydrodynamic load of the vibration response is unknown. First, in this paper, a typical hydrodynamic load is used as the input, the ANSYS finite element model is established for transient analysis. The dynamic displacement response time history of the measuring point is extracted as the known condition of the inverse analysis method. Secondly, the dynamic displacement response spectrum of these measurements is used as the known input. The basic program of inverse analysis is made to induce the hydrodynamic load of the vibration response of the guide wall, and the identification of the vibration source is realized. The feasibility of the inverse analysis method is verified by comparing the measured value of the dynamic water load with the calculated value. Finally, the whole dynamic displacement response of the whole guide wall structure is calculated by the positive analysis of the identified dynamic water load. The dynamic stress response of the whole structure is compared with the modal superposition method. The comparison between the inversion results and the transient response shows that the error is controlled within 5%, and the inverse analysis method of the vibration response of the discharge structure is proved to be effective and feasible. (2) the original two beach arch dam based on the finite test point is carried out. The dynamic response field inversion of the two beach arch dam is taken as an example. The dynamic displacement vibration response test is carried out for the six different discharge conditions of the arch dam. The dynamic displacement field and the dynamic stress field of the whole dam are retrieved according to the measured results of the dynamic displacement of the finite measuring point. The B1~B7 measurement point of the two beach arch dam is measured under each working condition. The displacement response time course is used to reverse the analysis of three equivalent dynamic water loads when the arch dam is discharged. The genetic algorithm is introduced to optimize the identification results. Based on the positive analysis of the three equivalent loads on the anti performance, the whole dynamic displacement field of the arch dam is calculated, and it is compared with the root mean square root of the dynamic displacement response of the known test points. The integral dynamic stress field of arch dam archetype structure of the above six working conditions is retrieved by state superposition method, and the dynamic stress of the dam body is obtained, and the dynamic stress results of the large stress part of the dam are analyzed. The inversion results show that: (1) the root value of the dynamic displacement response of each node on the same elevation arch ring of the arch dam shows "the middle large, two sides". The trend of the change of the shear stress response on the arch and the response of the dynamic displacement is similar. (3) the root value of the tangential dynamic stress decreases with the elevation, and the root value of the vertical dynamic stress gradually increases with the elevation. (3) the existing safety evaluation criteria for the existing structural vibration are carried out. According to the investigation and analysis, and in combination with the inversion results of the dynamic displacement field and dynamic stress field of the two beach arch dam prototype, the operation safety of the two beach arch dam under the six conditions is evaluated. The results show that the flood discharge vibration of the two beach arch dam is safe under the six operating conditions.
【學(xué)位授予單位】：南昌大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：TV312

【參考文獻(xiàn)】

相關(guān)期刊論文 前3條

1 郄志紅,鄭旌輝,劉春來(lái);反分析及其在水利工程中的應(yīng)用[J];海河水利;1999年03期

2 潘德嘉,謝省宗;紊流邊界層壓力脈動(dòng)作用下泄水建筑物的隨機(jī)振動(dòng)分析[J];水力發(fā)電學(xué)報(bào);1984年01期

3 吳一紅,謝省宗;水工結(jié)構(gòu)流固耦合動(dòng)力特性分析[J];水利學(xué)報(bào);1995年01期

，

本文編號(hào)：1934590