Reception Plate Method for Structure-Borne Sound Sources

目前还没有可用的实际方法来表征振声源，振声源通过支撑件和其他接触件激励支撑和周围结构振动。该提案的背景涉及由于机器振动被传输到接收结构，随后作为噪声从结构传播和重新辐射而引起的噪声的预测和控制。实际上，是指实验室方法，它产生简化形式的源数据，这些数据可以转化为安装条件下结构承载功率的预测。虽然一般来说，空气传播源已成功地纳入预测模型参考空气传播声功率，它还没有可能纳入结构传播源在类似的基础上。在寻求结构源特性方面存在两个主要挑战。首先，一个源特性需要考虑的振动活动和结构动力学与支持和周围的结构接触。其次，振动传递过程是复杂的，完整的描述需要大量的数据集，并且是实验和计算密集型的。然而，设计工程师，测试室经理和顾问需要基于实验室的测量系统，将产生源强度的单一值和传统的观点是，这些实际的要求与物理和准确的源特性的要求相冲突。本研究的核心是通过发展和评价一种新的结构声源特性的接收板方法来解决这一冲突。受试机器连接到高迁移率板，从该板以自由源的速度的形式间接获得源活动（即，就好像机器自由悬挂）。然后将机器连接到低移动性板上，以间接获得阻挡力（即，就像机器连接到惰性结构上一样）。从这两个量，源的迁移率得到没有直接测量。这种方法的基本优点是，耗时和复杂的过程中，直接获得源的活动和动态的每个接触，并为每个组件的激励，被取代为一个间接的方法，只需要测量的响应速度的简单连接板。

There are not presently available practical methods of characterising vibro-acoustic sources, which excite supporting and surrounding structures into vibration through the supports and other contacts. The context of the proposal concerns the prediction and control of noise due to machine vibrations being transmitted to a receiving structure, subsequently propagating and re-radiating from the structure as noise. By practical, is meant laboratory methods which yield source data in reduced form, which can be transformed into a prediction of the structure-borne power in the installed condition. Whilst generally, airborne sources have been successfully incorporated into prediction models by reference to airborne sound power, it has not yet been possible to incorporate structure-borne sources on a similar basis. There are two main challenges in seeking a structure-borne source characterisation. First, a source characterisation requires consideration of both the vibration activity and the structural dynamics at the contacts with supporting and surrounding structures. Secondly, the vibration transmission process is complicated and a full description requires a large data set and is experimentally and computationally intensive. However, design engineers, test-house managers and consultants require laboratory-based measurement systems which will yield single values of source strength and the conventional view is that these practical requirements conflict with the requirements for a physical and accurate source characterisation. The core of this investigation is to address this conflict by developing and appraising a novel reception plate method of structure-borne sound source characterisation. The machine under test is attached to a high-mobility plate, from which the source activity is obtained indirectly in the form of the velocity of the free source (i.e. as if the machine had been freely suspended). The machine then is attached to a low-mobility plate to indirectly obtain the blocked force (i.e. as if the machine had been attached to an inert structure). From these two quantities, the source mobility is obtained without direct measurement.The fundamental advantage of this method is that the time consuming and complicated process of directly acquiring the source activity and dynamics for each contact, and for each component of excitation, is replaced with an indirect method which only requires measurement of the response velocity of simple attached plates.