本文選題：隨機振動 + 減小截至模態(tài)的虛擬激勵法　； 參考：《南京航空航天大學》2014年碩士論文

【摘要】：隨機振動主要研究動力學系統(tǒng)在隨機激勵作用下的響應特性,在機械、航空、航天、汽車、船舶等領域中存在著大量的隨機振動,如飛行器的起飛、著陸、飛行過程及再發(fā)等等。如果重新設計結構的外形尺寸以降低其振動水平,需要花費大量時間與金錢。在振動結構上安裝吸振器是解決結構振動問題的有效措施之一,采用附加吸振器的方法不僅可以抑制確定性的振動,還能抑制隨機振動,有著廣泛的工程應用。對于受隨機載荷的機械結構的動力學優(yōu)化設計,首先,由被吸振結構的共振頻率初步確定吸振器的剛度形式和質量大小,并利用基于減小截至模態(tài)的虛擬激勵法進行譜響應的計算分析。然后對吸振器和被吸振結構整體進行動力學優(yōu)化設計,選取合適的優(yōu)化算法,以吸振器的動能最大為優(yōu)化目標,以結構若干響應點的隨機振動最大位移CRMS值為優(yōu)化約束條件,分析了動力吸振器的吸振效率。最后,對吸振器的安裝位置選擇,確定吸振器在結構上的最佳安裝位置。算例中以某艙體作為被吸振結構進行了動力學優(yōu)化設計,結果表明了動力吸振器優(yōu)化設計的有效性。本文的研究拓展了動力學優(yōu)化設計在結構力學領域的應用范圍。
[Abstract]:Random vibration mainly studies the response characteristics of dynamic system under random excitation. There are a large number of random vibration in mechanical, aviation, aerospace, automobile, ship and other fields, such as the take-off and landing of aircraft. Flight and re-launch, etc. It takes a lot of time and money to redesign the shape of the structure to reduce its vibration level. The installation of vibration absorbers on vibration structures is one of the effective measures to solve the structural vibration problems. The method of adding vibration absorbers can not only suppress the deterministic vibration but also suppress the random vibration, so it has a wide range of engineering applications. For the dynamic optimization design of mechanical structures subjected to random loads, firstly, the stiffness and mass of the vibration absorbers are preliminarily determined by the resonance frequency of the structure. The spectral response is calculated and analyzed by using the virtual excitation method based on reducing the terminal mode. Then the dynamic optimization design of the vibration absorber and the whole structure is carried out, and the appropriate optimization algorithm is selected. The maximum kinetic energy of the absorber is taken as the optimization objective, and the maximum displacement CRMS value of random vibration of some response points of the structure is taken as the optimal constraint condition. The efficiency of dynamic vibration absorber is analyzed. Finally, the optimal installation position of the absorber is determined by selecting the installation position of the absorber. The dynamic optimization design of a cabin as the vibration absorbing structure is carried out, and the results show that the optimal design of the dynamic vibration absorber is effective. The research in this paper extends the application of dynamic optimization design in the field of structural mechanics.
【學位授予單位】：南京航空航天大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TB535.1

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本文編號：1977215