一、引 言 利用声波可以检测材料内的“伤”.这种检测通常称为声学检测,声学检测可以分为传播检测和振动检测两类,传播检测是利用声波的传播特性,振动检测则是利用被检测材料的振动特性.声阻法是振动检测中的一种方法,它把反映材料振动特性的力阻抗转换为换能器的负载阻抗,而材 I. INTRODUCTION The use of sound waves to detect “wounds” in materials is commonly referred to as acoustic detection. Acoustic detection can be divided into two types: propagation detection and vibration detection. Transmission detection utilizes the propagation characteristics of sound waves while vibration detection utilizes Vibration characteristics of the material being tested Acoustic impedance method is a method of vibration detection that converts the force impedance that reflects the vibration characteristics of the material into the load impedance of the transducer,