Integrated measurement of ultrasonic parameters for polymeric materials via full spectrum analysis

Ultrasound velocity and attenuation coefficient are important parameters for characterizing polymeric materials. How to accurately and conveniently measure ultrasonic parameters is always a significant topic. This paper presents a novel method for integrally measuring ultrasonic parameters via full spectrum analysis (UFSA). Reflected signals from the upper and lower surfaces of the polymeric materials are connected by a frequency dependent transfer function. The logarithm of the transfer function can be linearly fitted, and the ultrasonic parameters, including the ultrasound velocity and attenuation coefficient, can be calculated from the vertical intercept and slope of the fitting line. Experiments with various polymeric materials of different stiffnesses and dimensions, as well as several influence factors, were carried out to verify the proposed UFSA method. Compared to the conventional method, the proposed method does not need to measure the thickness of the polymeric material and makes full use of data in measured waves. Experimental results showed that the proposed method has high accuracy in measuring ultrasonic parameters and characterizing flexible materials. The proposed method would have broad applications in polymer testing.