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超聲波焊接原理

盤式活塞聲源聲場

超声波的特点是振动频率高、波长短，例如1mc/s的超声波在空气中的波长为0.34 mm，在水中为1.4 mm。因此，很多情况下声源比波长大。

假設在沒有吸收的媒質中，半徑爲a的圓板聲源以活塞狀振動，在聲源的前方形成聲場，當a比波長λ大時，Z軸上的聲場的波面除了在聲源附近以外，都在聲源面上變得平行。

接著求聲場的強度分布，在離聲源中心的距離r比a足夠大的點上，壓力振幅p爲

靈科超聲波

中表示(圖21).

靈科超聲波

因此貝塞爾函數最初爲0

靈科超聲波

*)音速與彈性模量M有u=(M/)^1/2的关系，因此将M写成复量M*=M'+jM"，M’’/M’是损失系数(在M"?M’的情况下). M"/M’也常被称为tan 。另外，損耗系數的倒數用字母Q表示，M’’/ω是固體的內部粘性率。

即

靈科超聲波

的方向，如果λ比a小，那麽θ也小，聲波具有尖銳的方向性。這就是超聲波用于測深和探傷的原因。

聲源附近的強度分布變得非常複雜，在與z軸垂直的面內，強度的極大和極小呈同心圓狀分布，軸上的強度由下式給出。

靈科超聲波

圖22示出了這一點，在z

借用光學術語，這個區域被稱爲Fresnel區域。在z>α?/λ的範圍中，大致與1/z?成比例，這個區域稱爲Fraunhofer區。

在測量媒質的吸收系數時，必須注意這個強度分布，如果媒質有吸收(吸收系數α)，Fraunhofer區域的強度與e-2αz/z?成比例變化，在Fresnel領域並不簡單。但衆所周知，在Fresnel區域中，在比與聲源平行的聲源寬的面中，測量面內強度的平均值時，其值大致與平行平面波一樣，與e-2αz成比例變化。

以上就是肇慶靈科超聲波爲大家介紹關于超聲波焊接機的相關信息，如果大家對焊接設備需要更深一步的了解，歡迎致電公司電話：0756-8626887，或者打開公司官網：/，我们很乐意为大家服务！

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超聲波反射和折射

超聲波切割和傳統切割相比有什麽優勢？

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