本文的主旨是在探討引擎與活塞式液壓避震器偶合系統的動態特性。此振動系統係由一引擎和一活塞式液壓避震器所組成，兩者之間以二線性彈簧連接之。本文首先使用Lagrange方程式來推導整個振動系統的運動方程式，接著使用傳統的解析法來求整個系統自由振動和強迫振動的閉式解(closed-form solutions)，以求得振動系統的動態反應。本文重點在探討，下列參數對振動系統動態反應與自然頻率的影響：引擎和活塞裝置的質量比、在引擎下的彈簧常數和在活塞裝置下的彈簧常數之比、活塞裝置下的支撐阻尼器係數、孔直徑和活塞直徑之比、圓盤厚度、液體黏度及引擎激振力的頻率等。因為這些參數均會改變系統的自然頻率，因此調整參數的大小，以使得系統的自然頻率遠離外力激振頻率，將可大幅降低系統振動反應的振幅。

　　The objective of this thesis is ‘Dynamic analysis of the coupled system of engine and piston-type hydraulic mounting’. This coupled system consists of an engine and a piston assemblage, and in order to make a connection between engine and piston assemblage, two linear springs were used. In this article, we use Lagrange’s equation to derive the equation of motion. And we use traditional analysis to derive closed-form solutions from free vibration and force vibration. Finally we get the dynamic response of the coupled system.
　　In this article, we focus on research the influences of dynamic responses and nature frequencies by following parameters: ratio of engine mass to piston-assemblage mass, ratio of spring constant under engine to that under piston, ratio of orifice diameter to piston diameter, damping coefficient of the support under piston assemblage, thickness of orifice plate, kinematical viscosity of fluid, frequency of exciting force from engine. Those parameters would change the nature frequencies, so with adjusting those parameters, we can keep the nature frequencies of this coupled system away from the frequency of exciting force. And this would lead to a decreasing of response of coupled system substantially.

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