Determination of acoustical material properties (BeKAM)

新的混合聚合物材料的发展是当前和未来的标志，与旧材料相比，这种材料在成本效益方面相当优越。越来越多地使用这些材料导致在超声测量技术领域的新的可能性和加剧的因素。合成材料提供了更多的自由度来设计结构和声学功能元素。它们相当复杂的声学特性是不利的。频率和主要依赖于方向的声速、声吸收和声阻抗随着温度、年龄或含水量的变化而变化很大，这与金属不同。在设计过程中，了解这些变化的材料属性的范围是很重要的。目前，这种材料特征量既没有标准化，也没有必要的规模。使用基于波导的测量系统，所有相关的声学材料特性都应该只用一个条件良好的标准化测试样品来确定，并在数据库中提供。

The presence is and the future will be marked by the development of new hybrid polymer materials, which considerably are superior in terms of cost effectiveness in comparison to the old material generation. Increasing use of such materials leads in the area of the ultrasound based measuring technology both to new possibilities and to aggravating factors. Synthetic materials offer substantially more degrees of freedom to design constructive as well as acoustically functional elements. Their considerably more complex acoustic qualities are adverse. The frequency and mostly direction-dependent sound velocity, sound absorption and acoustical impedance vary considerably with the temperature, the age or the water content differently than at metals. It is important to know the range of these changed material properties to consider that during the design process. At present, such material characteristic quantities are neither standardized nor available on the necessary scale. With a wave guide based measurement system all relevant acoustical material properties shall be determined with only a well-conditioned, standardized test specimen and made available in a database.