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CHAPTER 8Transmission and Radiation of Sound byThin PlatesPaul J. T. FilippiIntroduction In many practical situations, a sound waveis generated by the vibrations of an elastic structure: let us mention musicalinstruments like a guitar, a violin, a piano, a drum, etc.; industrial machines like anelectric transformer, a tool machine, all sorts of motors, etc.; in a building, noiseis transmitted through the structures (windows, floors, walls) because, for somereason, they are set into vibrations; there are also a lot of domestic noise and soundsources, like a door bell, a loudspeaker, a washing machine, a coffee grinder, etc.,the vibrations of which generate noise. This is a very short list of noise generation byvibrating structures.A reciprocal aspect of this phenomenon isthe vibration of a structure generated by an incident acoustic wave. A classicalexample is commonly reported. A flautist or violinist is playing in a party whilepeople are drinking champagne in crystal glasses; suddenly he plays a note exactlytuned on a resonance frequency of one of the glasses which starts vibrating withsuch a large amplitude that it breaks apart and the champagne is for the rug. Anothervery old and excessively common example is the mechanics of the ear: theair, excited by an acoustic wave, makes the eardrum move and, in its turn, the eardrumgenerates a motion of the ear bones which excite the auditory nerve. Finally,let us mention that the fundamental part of a microphone is a membrane which is setinto vibrations by sound fields


These two aspects of the phenomenon can occur at the same time: a sound field excites a structure which then creates a second sound field. This is why it is possible to hear external noises inside a room.

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All these phenomena are, in fact, various aspects of a single one: the interaction between a compressible fluid and a vibrating structure. This part of mechanics is often called vibro-acoustics.

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This chapter starts with a very simple one-dimensional example: a wave guide separated into two parts by a mass/spring system which can move in the axial direction. Sound can be generated by this structure or transmitted through it. The

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  • 9 年前

    第8章聲音的傳輸和輻射由稀薄的板材保羅J。 T. Filippi介紹在許多實用情況,一個有彈性結構的振動引起的酣然的waveis : 讓我們提及musicalinstruments像吉他、小提琴、鋼琴、鼓等等; 工業機器喜歡anelectric變壓器、工具機器、各種各樣的馬達等等; 在大廈,通過結構被傳送的noiseis (窗口、地板,牆壁),因為,為somereason,他們被設置入振動; 也有很多國內噪聲和soundsources,像門鈴、擴音器、洗衣機、磨咖啡器等等,振動,其中引起噪聲。 這是噪聲產生byvibrating的結構一個非常最後的名單。這種現象的一個相互方面是事件音波引起的結構的振動。 classicalexample共同地報告。 笛手或小提琴手充當whilepeople在水晶玻璃喝香檳的黨; 他在開始振動withsuch每大高度它分開的共鳴頻率突然播放筆記exactlytuned其中一塊玻璃,并且香檳是為地毯。 Anothervery老和過份地共同的例子是耳朵的技工: theair,激發由音波,做鼓膜移動,并且,它的輪, eardrumgenerates耳朵骨頭的行動哪些激發聽覺神經。 終於,讓我們提及話筒的基本部分是setinto振動由音場

    2011-07-08 15:41:03補充

    現象的這二個方面可能同時發生: 一個音場激發結構哪些然後創造第二聲領域。 這就是為什麼聽見外在噪聲在屋子裡面是可能的。

    2011-07-08 15:41 :10補充

    所有這些現象,實際上,是各種各樣的方面的一唯一一個: 可壓縮的流體和一個振動的結構之間的互作用。 機械工的這部分經常告訴vibro聲學。

    2011-07-08 15:41 :17

    本章開始以一個非常簡單的一維例子的補充: 波導分離了入二份由可能移動軸向方向的大量或春天系統。 聲音可以由這個結構引起或通過它被傳送。

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  • 瑤琹
    Lv 5
    9 年前




    保羅 J. T.菲利皮巴萊

    引言在許多實際情況,健全waveis產生的振動的彈性結構:讓我們提musicalinstruments像一把吉他,小提琴,鋼琴,鼓等;工業機器一樣 anelectric變壓器,機床,各種電機等;在建築物,noiseis傳播途徑的結構(窗戶,地板,牆壁),因為,對於 somereason,它們設置成震動,也有很多國內的噪音和soundsources,就像一個門鈴,一喇叭,一台洗衣機,咖啡研磨機等,其中振動產生的噪音。這是一個非常短的名單產生噪音byvibrating結構。

    互惠方面對這一現象 isthe結構振動產生的聲波事件。阿classicalexample是常見的。一個長笛或小提琴演奏是在黨的whilepeople喝香檳酒的水晶眼鏡,突然他打一張紙條 exactlytuned共振頻率上的眼鏡一開始振動 withsuch的振幅大,它打破分開,香檳是為地毯。 Anothervery老過分常見的例子是力學的耳朵:theair,激發​​聲波,使耳膜移動,並在其反過來,eardrumgenerates議案的耳骨的激發聽覺神經。最後,讓我們提的是,基礎部分的麥克風是一種膜是setinto振動的聲場



    本章開始於一個非常簡單的一維例如:波導分成兩部分通過質量 /彈簧系統,可在軸向方向移動。聲音可以由這個結構或傳輸通過它。該

    參考資料: 自己是翻譯機
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