Development of a Simple Ultrasonic-Based Apparatus for Dynamic Property Measurement in Material Screening

Understanding the dynamic behavior of materials is essential in structural design, particularly in applications that are subject to vibration, impact, and cyclic loading. These include automotive and electric vehicle (EV) components where vibration damping is a critical design consideration. While static property testing is fairly accessible, dynamic property evaluation is still less facilitated due to the complexity and high cost of standardized equipment. This study presents the development of a simple apparatus for measuring the natural frequency and damping ratio of slender beam specimens using an ultrasonic sensor, designed for quick and accessible material testing. Ultrasonic sensor was selected for its affordability and practicality compared to other instruments. The method is based on analyzing free vibration responses of cantilever beam, capturing the oscillating displacement. Fast Fourier Transform (FFT) was applied to determine natural frequency, while the envelope decay curve method was chosen to obtain damping ratio. Vibration experiments were conducted on 3D-printed polylactic acid (PLA) and aluminum beams due to their well-established mechanical properties. Results from the apparatus were compared against accelerometer measurements and theoretical calculations. A calibration factor was established to improve measurement accuracy. Despite its simplicity, the apparatus presents consistent and sufficiently precise results, making it suitable for early-stage material screening, quality control check, and educational applications.