非線性懸吊彈性樑及端點減振器之研究

[[abstract]]本研究考慮一Bernoulli-Euler Beam 之彈性樑以鋼纜懸掛，而鋼纜以非線性彈簧與線性阻尼組成，彈性樑的一端為鉸接邊界支撐，另一端則掛載時變之動態減振器 (DVA) 。本研究因具有時間變化之邊界條件，所以採用 Mindlin-Goodman 法分析此問題。此外本文使用多尺度法解析此非線性系統，發現系統中第一模態及第二模態存在一對三的內共振情形，並繪製系統於穩態固定點的情況下，各模態的頻率響應圖，以觀察其非線性內共振現象，且以數值模擬其時間域之振動情形，相互驗證之。另外本研究將分析DVA 的質量及彈簧係數對於整個系統之減振影響，並提出最佳的質量與彈簧係數組 合，可使系統達到最佳減振效果。最後，吾人以一簡單的空氣動力函數模擬氣流對於本彈性樑系統之阻尼的影響，利用Floquet Theory 搭配Floquet Multipliers (F.M.) 判定法則，繪製出Basin of Attraction圖形，觀察此系統之穩定性，以獲得最後結論。[[abstract]]This study investigated the performance of a mass-spring dynamic vibration absorber (DVA) at the free end of a hinged-free elastic beam under simple harmonic excitation. This beam system was suspended by suspension cables. These cables were simulated by cubic nonlinear springs to examine the nonlinear characteristics of this system. This time-dependent non-homogeneous boundary condition problem was solved by Mindlin-Goodman method. The method of multiple scales was performed to solve the nonlinear equations. The 1:3 internal resonance was found at the 1st and 2nd modes of this beam system. The fixed point plots were obtained and compared with the numerical results to verify the system internal resonance. The Poincaré Map was also utilized to identify the system instability frequency region of the jump phenomenon. The optimal DVA mass and the spring constant were provided for best beam vibration reduction. Finally, the wind speeds and aerodynamic loads were included to investigate the stability of this system. The system stability was analyzed by Floquet theory and Floquet multipliers. The basin of attraction charts were made to verify the effects of the combinations of DVA’s mass and the spring constant at diverge speed.[[sponsorship]]中華民國航太學會; 淡江大學機電工程學系; 淡江大學航空太空工程學系[[cooperationtype]]國內[[conferencetype]]國內[[conferencetkucampus]]淡水校園[[conferencedate]]20131130~20131130[[booktype]]電子版[[iscallforpapers]]Y[[conferencelocation]]新北市, 臺

減振器位置對於雙層振動平板減振效能之研究

[[sponsorship]]中華民國航空太空學會; 交通大學機械工程系; 交通大學前瞻火箭研究中心; 國家科學委員會工程技術發展處工程科技推展中心[[conferencetype]]兩岸[[conferencedate]]20121215~20121215[[booktype]]電子版[[iscallforpapers]]Y[[conferencelocation]]新竹, 臺

Design of Hybrid Dynamic Balancer and Vibration Absorber

[[abstract]]This study proposed a novel hybrid dynamic balancer and vibration absorber that is cheaper than active dampers and more effective than passive dampers. The proposed damping system does not need to be altered structurally to deal with different damping targets. Rather, the proposed vibration absorber is capable of self-adjustment to the optimal damping location in order to achieve balance and, thereby, optimize damping effects. The proposed device includes a groove under the damping target with inertial mass hung from a coil spring beneath. This allows the device to bounce vertically or rotate in order to reduce vibrations in the main body. The coil spring vibration absorber can also slide along the groove in order to adjust its location continuously until the vibrations in the system are minimized and the main body is balanced. Experiments verify the efficacy of the proposed device in improving damping performance beyond what has been achieved using conventional devices. We also provide an explanation of the theoretical underpinnings of the design as well as the implications of these findings with regard to future developments.[[notice]]補正完畢[[journaltype]]國外[[incitationindex]]SCI[[cooperationtype]]國外[[ispeerreviewed]]Y[[booktype]]電子版[[countrycodes]]NL

[[alternative]]The Dynamic Response of Composite Rotor-Wake Coupled System

計畫編號：NSC92-2212-E032-008研究期間：200308~200407研究經費：384,000[[sponsorship]]行政院國家科學委員

The Effects of Wake Dynamics and Trailing Edge Flap on Wind Turbine Blade

[[abstract]]In the present study, we considered the bladewake interaction (BWI) and the TEF span length, index angle on a turbine blade. The aerodynamic loads and the stresses on the blade were studied. The wake dynamic theory, BEM, and the ANSYS-FORTRAN APDL method were employed. Results were correlation with a small turbine for blade stress distribution. The blade lift distribution was also compared with numerical results from [6]. Finally, the wake and the TEF configuration effects on a 5MW turbine blade in the lift distribution and stresses were presented in this work.[[cooperationtype]]國內[[conferencetype]]國際[[conferencetkucampus]]淡水校園[[conferencedate]]20140623~20140628[[booktype]]電子版[[iscallforpapers]]Y[[conferencelocation]]New Taipei City, Taiwa

可調式之多質點減振器對於振動機構減振效能之研究

[[sponsorship]]北京航空航天大學[[conferencetype]]兩岸[[conferencedate]]20120903~20120905[[booktype]]紙本[[iscallforpapers]]Y[[conferencelocation]]北京市, 中

非線性懸吊彈性樑及端點減振器之研究

[[abstract]]本文考慮一鋼纜懸掛之Bernoulli-Euler Beam彈性樑，此鋼纜以非線性彈簧與線性阻尼的組成模擬之。此懸吊系統可模擬一般吊橋之振動方式，若將此懸吊之非線性彈簧與線性阻尼倒置於彈性樑之下，又可模擬此彈性樑置於 Winkler type 彈性基座的振動方式，可模擬一般之鐵路、捷運等軌道振動系統，亦可初步模擬奈米碳管 (Carbon Nano Tube) 置放彈性基底 (Elastic Matrix) 之振動模型，因此應用極為廣泛。本研究中，彈性樑的一端為鉸接邊界支撐，另一端則掛載一端點邊界與時間相關動態減振器 (Time-Dependent Boundary Dynamic Vibration Absorber (TDB DVA)) 。其目的乃是期望找出一組最佳之TDB DVA，以利主體之減振。此外，本研究並考慮主體受到簡諧外力及空氣動力之影響，使之成為氣體彈性系統。有別於一般的振動問題之邊界設定，本研究之自由端點 (Free End) 因掛載一DVA，而為具有時間變化之邊界條件，因此吾人採用 Mindlin-Goodman 法分析此問題。 此外，本文並使用多尺度法 (Method of Multiple Scales (MOMS) ) 解析系統於穩態固定點 (Fixed Points) 各模態之頻率響應，且藉由振幅及振動模態觀察其非線性內共振現象。本研究並以解析法求出此橫樑之主體架構第一和第二個模態 (mode) 之間，於支撐或懸吊彈性系統之無因次彈性係數為6.6751166時，會有1對3 (1：3) 的內共振情形產生。因此，本文進一步分析端點DVA的質量及彈簧係數對於整個系統之減振的影響，最後，將以數值法分析時間域內的位移變化，並利用 Floquet Theory 繪製 Basin of Attraction plots判定振動系統的起始狀況，對於穩定性的影響。除了與頻率域之振幅比對，亦可提供此非線性系統之振動特性。[[notice]]補正完

高度経済成長期社会教育史研究(3) : 東京都国立市公民館報に見る地域変貌と住民の学習

departmental bulletin pape

[[alternative]]Study of Parameter Excitation of Dynamic Vibration absorbs

[[abstract]]本研究目的是研究一考慮參數激擾共振影響的動態減振器，在主體兩自由度的振動影響下穩定情形。此動態減振器由一非線性彈簧及質量塊組成，主體可視為精密加工或是傳統產業的機械製造工具機的基座。利用牛頓力學法、Lagrange法和時間多尺度法分析及推導此減振器的運動方程式，求出振 動頻率與振幅相對曲線，找出不穩定區域並求得能有最佳減震效果的耦合彈性係數及彈簧下質量塊的質量（轉動慣量）。[[sponsorship]]中華民國航太學會[[sponsorship]]成功大學航空太空工程學系[[cooperationtype]]國內[[conferencetype]]國內[[conferencedate]]20141115~20141115[[booktype]]電子版[[iscallforpapers]]Y[[conferencelocation]]台南市, 台

固定鉸接自由邊界平板之亂數外力激擾之發電研究

補正完畢國內台南市，台灣TW