尺寸和发射频率对换能器声场影响仿真分析

摘要

The size and the exciting frequency of the transducer have an important influence on the sound field distribution, so it is great significant for people to understand the laws of this affection in the fight choice for transducers in actual process of Ultrasonic Testing. This paper studies how the size and exciting frequency influence on the fadiaton field of transducer by simulation. The difficulty lies in the establishment of mathematical model. The mathematical models given by the past articles have many defects, for example, they can not give the analytical expressions of the whole sound field radiated by the transduce, and the use of a numerical method of calculation is very cumbersome. The Gaussian beam model used in this paper overcomes the shortcomings of previous methods, and it can provide a simple analytical expression describing the sound field radiated by the transducer. This paper adopts this method with the Matlab software to simulate the different sizes and different exciting frequencies of circular piston transducer sound field, and gives the laws that how the size and exciting frequency influence on the radiaton field of transducer intuitively.%在实际探伤过程的研究中,超声换能器的尺寸和发射频率,对辐射声场分布及指向性特征直接影响探伤效果,正确选择换能器具有重要意义.为了正确进行探伤并保证效果,对尺寸及发射频率对换能器辐射声场的影响进行分析.对超声波声场进行仿真的难点在于数学模型的建立,以往给出的数学模型有很多缺陷,无法给出整个换能器辐射声场的解析表达式.采用的高斯声束模型克服了以往方法的缺陷,能够以简单的解析表达式描述整个换能器辐射声场,并在Matlab中仿真了不同尺寸和不同发射频率的圆形活塞换能器的辐射声场,可正确地分析尺寸及发射频率,为换能器辐射声场的设计提供依据.