Université du Maine, Le Mans Cedex, France.
J Acoust Soc Am. 2011 Aug;130(2):818-25. doi: 10.1121/1.3605535.
The modification of elastic properties of compressed acoustic foams is investigated. The porous sample is first submitted to a static compression and then to a dynamic excitation of smaller amplitude, corresponding to acoustical applications. The static compression induces the modification of the dynamic elastic parameters of the material. This work focuses on Young's modulus. The variation is measured with two different experimental methods: The classical rigidimeter and an absorption measurement. The effective Young's modulus is directly measured with the first method and is indirectly determined through the quarter-wave length resonance of the frame with the second one. The results of the two measurements are compared and give similar tendencies. The variation of the dynamic Young's modulus as a function of the degree of compression of the sample is shown to be separated in several zones. In the zones associated with weak compression (those usually zones encountered in practice), the variation of the effective Young's modulus can be approximated by a simple affine function. The results are compared for different foams. A simple model of the dependency of the Young's modulus with respect to the static degree of compression is finally proposed for weak compressions.
研究了压缩吸声泡沫弹性性能的变化。多孔样品首先进行静态压缩，然后进行较小振幅的动态激发，以适应声学应用。静态压缩会引起材料动态弹性参数的变化。本工作重点研究杨氏模量。通过两种不同的实验方法测量其变化：经典刚性计和吸收测量。第一种方法直接测量有效杨氏模量，第二种方法通过框架的四分之一波长共振间接确定。两种测量结果的趋势相似。结果表明，随着样品压缩程度的变化，动态杨氏模量的变化可分为几个区域。在与弱压缩相关的区域（通常是实际中遇到的区域），有效杨氏模量的变化可以用简单的仿射函数来近似。对不同的泡沫体进行了比较。最后，针对弱压缩，提出了杨氏模量随静态压缩程度变化的简单模型。
