Coordination Funds

超声波传感器和致动器在科学和技术中被广泛应用。在这些部件的设计和优化中，越来越多地使用计算机技术。该过程中的问题之一是对压电材料或所制造的压电部件的声学或机电材料特性的了解不足。根据目前的技术水平，这些材料特性是使用几种不同处理的材料样品来确定的，结果是材料参数设置不一致。这尤其适用于在较高功率范围内应用的压电陶瓷材料的表征，例如在高功率超声应用中，其中必须考虑材料的非线性特性。由于阻尼的压电材料的耗散特性也必须考虑。以下是本研究项目的主要目标：测量方法和测量系统的表征的压电陶瓷材料的热和压电材料的行为被开发。借助定制的优化方法，确定完整和一致的材料参数集。测量方法和测量系统的开发，使材料参数的确定基于一个单一的压电陶瓷样品的几何形状，是典型的高功率的应用。为此，有必要开发合适的材料模型来描述数学的非线性材料行为。此外，这些材料模型必须适合于在基于瞬态不连续Galerkin方法的仿真环境中有效地实现，该方法将在本项目范围内开发。应该指出的是，计划表征方法是基于对压电陶瓷行为的连续物理考虑。原子的、微尺度的效应通过其对材料行为的有效影响而被隐含地考虑。由于含铅压电陶瓷的使用有望在未来被禁止，为压电陶瓷材料提供新的表征方法和创建高性能的仿真环境将支持无铅压电材料的替代，尤其是中小企业将从中受益。此外，预计这种表征方法也将间接地对新型高效压电材料的开发和制造工艺的改进产生积极影响。

Ultrasonic sensors and actuators are used in a wide range of applications in science and technology. In the design and optimization of these components, computer technology is increasingly used. One of the problems in this procedure is the insufficient knowledge of the acoustic or electromechanical material properties of the piezoelectric materials or the manufactured piezoelectric components. According to the current state of the art, these material properties are determined using several differently processed material samples, with the result that the material parameter set is inconsistent.This applies in particular to the characterization of piezoceramic materials applied in the higher power range, for example in high-power ultrasonic applications where the nonlinear properties of the materials must be taken into account. The dissipative properties of piezoelectric materials due to damping must also be considered.The following are the main objectives for this research project: Measurement methods and measurement systems for the characterization of the thermal and piezoelectric material behaviour of piezoceramic materials are to be developed. Aided by tailored optimization methods, complete and consistent material parameter sets are determined. Measurement methods and measurement systems are developed to enable the determination of the material parameters based on a single piezoceramic sample of a geometry that is typical for high-power applications.To this end, it is necessary to develop suitable material models to describe the nonlinear material behaviour mathematically. In addition, these material models must be suitable to be efficiently implemented in a simulation environment based on the transient discontinuous Galerkin method, which is to be developed within the scope of this project.It should be pointed out that the planed characterization method is based on continuum physical considerations of the behaviour of piezoelectric ceramics. Atomistic, micro-scale effects are considered implicitly via their effective influence on the material behaviour.Since a ban on the use of piezoceramics that contain lead is expected in the future, the provision of a new characterization methodology for piezoceramic materials and the creation of a high-performance simulation environment will support the substitution by lead-free piezoelectric materials, from which small and medium-sized companies in particular will benefit. In addition, it is to be expected that this characterization method will indirectly also have a positive influence on the development of new, highly efficient piezoelectric materials and on the improvement of the manufacturing processes.