本文選題：車橋耦合系統(tǒng)　切入點：移動彈簧質(zhì)量　出處：《石家莊鐵道大學》2015年碩士論文

【摘要】：近年來,車橋耦合系統(tǒng)在交通、土木、機械工程領域始終是熱點課題之一。當車輛的振動頻率和橋梁的固有頻率相等或接近時,會產(chǎn)生共振,直接影響車輛和梁橋的使用壽命和工作狀態(tài)。因此,車橋耦合系統(tǒng)的減振問題具有重要地位。事實上,移動載荷的不同會導致車橋耦合系統(tǒng)的頻率也隨之發(fā)生變化。因此,構(gòu)建一種新型的變頻非線性減振器成為科學與工程研究亟待解決的課題。SD(光滑不連續(xù))振子的頻率依賴于光滑參數(shù)的變化而變化。本文在SD(光滑不連續(xù))振子的基礎上構(gòu)建變頻減振器,研究變頻減振器(SD振子)—梁橋耦合系統(tǒng)的動力學行為和功率流特性。本文具體內(nèi)容如下:第一章,介紹文章選題的背景與意義,綜述國內(nèi)外動力減振裝置、SD振子和功率流理論及應用的相關研究和存在的問題。第二章,研究由減振器和軸向載荷作用下的梁橋組成的兩自由度耦合系統(tǒng)。首先,建立了系統(tǒng)的運動方程,并利用伽遼金離散得到無量綱化方程。然后,利用諧波平衡法得到振動系統(tǒng)功率流的表達式。最后,通過數(shù)值模擬研究了各參數(shù)對減振效果的影響規(guī)律。結(jié)果顯示SD減振器可以時而充當線性減振器時而充當非線性減振器,通過調(diào)節(jié)光滑參數(shù)來達到理想的減振效果。第三章,研究由移動彈簧質(zhì)量、減振器和軸向載荷作用梁橋組成的三自由度耦合系統(tǒng)。首先,利用可以表示出系統(tǒng)無限長時間內(nèi)運動狀態(tài)的函數(shù)建立系統(tǒng)運動方程,并得到系統(tǒng)運動的無量綱方程。然后,用多自由度系統(tǒng)的平均法得到系統(tǒng)穩(wěn)態(tài)運動時的幅頻響應函數(shù),并給出系統(tǒng)功率流的表達式。最后,通過數(shù)值模擬發(fā)現(xiàn):裸梁具有復雜的動力學行為,有周期、概周期和混沌運動,出現(xiàn)了分岔現(xiàn)象,而車橋—SD減振器耦合系統(tǒng)的功率流曲線平滑,達到了抑制混沌的目的,并且調(diào)節(jié)SD減振器參數(shù)具有減振效果。第四章,研究等間隔的載荷作用下梁橋的SD減振兩自由度系統(tǒng)。首先建立系統(tǒng)的振動方程。然后用Melnikov方法得到系統(tǒng)發(fā)生混沌的條件,運用平均法得到系統(tǒng)的幅頻響應函數(shù),并給出系統(tǒng)功率流的表達式。最后,利用Matlab進行數(shù)值模擬,發(fā)現(xiàn)裸梁有豐富的動力學現(xiàn)象,而車橋—SD減振器耦合系統(tǒng)的功率流曲線平滑,具有抑制混沌的作用,并且調(diào)節(jié)SD減振器參數(shù)達到了減振效果。第五章,總結(jié)全文的主要成果和創(chuàng)新點,指出研究車橋耦合系統(tǒng)存在的問題及今后的研究方向。
[Abstract]:In recent years, the vehicle-bridge coupling system has always been one of the hot topics in the field of traffic, civil engineering and mechanical engineering. When the vibration frequency of the vehicle is equal to or close to the natural frequency of the bridge, it will produce resonance. Therefore, the vibration reduction problem of vehicle-bridge coupling system plays an important role. In fact, the difference of moving load will cause the frequency of vehicle-bridge coupling system to change. Constructing a new type of frequency conversion nonlinear vibration absorber has become an urgent task for scientific and engineering research. The frequency of SD-oscillator depends on the variation of smooth parameters. In this paper, the frequency of SD-discontinuous oscillator is studied. Based on the construction of frequency conversion absorber, The dynamic behavior and power flow characteristics of the coupling system of SD vibrator and beam bridge are studied. The main contents of this paper are as follows: chapter 1, the background and significance of the selected topic are introduced. This paper summarizes the relevant research and existing problems in the theory and application of SD vibrator and power flow of dynamic vibration absorber at home and abroad. Chapter 2, the coupling system of two degrees of freedom composed of shock absorber and beam bridge under axial load is studied. The equations of motion of the system are established, and the dimensionless equations are obtained by Galerkin discretization. Then, the expressions of the power flow of the vibration system are obtained by using the harmonic balance method. The results show that SD absorber can act as linear shock absorber and nonlinear shock absorber at the same time, and achieve ideal damping effect by adjusting smooth parameters. A three degree of freedom coupling system consisting of moving spring mass, shock absorber and axial load acting beam bridge is studied. Firstly, the system motion equation is established by using the function which can express the motion state of the system for an infinite time. The dimensionless equation of the system motion is obtained. Then, the amplitude-frequency response function of the system is obtained by using the averaging method of the multi-degree-of-freedom system, and the expression of the power flow of the system is given. By numerical simulation, it is found that the bare beam has complex dynamic behavior, periodic, almost periodic and chaotic motion, and the bifurcation occurs, while the power flow curve of the vehicle-bridge / SD damper coupling system is smooth, and the purpose of suppressing chaos is achieved. And adjusting the parameters of SD absorber has the effect of damping vibration. In chapter 4, the two-degree-of-freedom system of beam bridge under the action of equal interval load is studied. First, the vibration equation of the system is established, and then the condition of chaos in the system is obtained by using Melnikov method. The amplitude-frequency response function of the system is obtained by using the averaging method, and the expression of the power flow of the system is given. Finally, numerical simulation with Matlab is carried out, and it is found that there are abundant dynamic phenomena in the bare beam, while the power flow curve of the vehicle-bridge / SD damper coupling system is smooth. It has the function of suppressing chaos and adjusting the parameters of SD absorber to achieve the effect of vibration reduction. Chapter 5 summarizes the main achievements and innovations of this paper and points out the problems existing in the study of vehicle-bridge coupling system and the future research direction.
【學位授予單位】：石家莊鐵道大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：U441.3

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本文編號：1679525