Determination of acoustical material properties (BeKAM)

新的杂化聚合物材料的存在和未来将以新的杂化聚合物材料的开发为标志，与旧的材料一代相比，这种材料在成本效益方面具有相当大的优势。越来越多地使用这种材料导致了基于超声波的测量技术领域的新的可能性和加剧的因素。合成材料为设计具有建设性和声学功能的元素提供了更多的自由度。他们相当复杂的音质是不利的。频率和大部分方向相关的声速、吸声系数和声阻抗随温度、龄期或含水率的变化较大，不同于金属。在设计过程中，重要的是要了解这些更改的材料属性的范围，以便进行考虑。目前，这样的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，只需条件良好的标准化测试样品即可确定所有相关的声学材料特性，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.