Optical scanning for structural vibration measurement

Abstract

High-speed cameras (HSCs) are often used for monitoring impacts and fast dynamic processes on structures. However, quantitative information about these processes is usually obtained through other means like accelerometers or Doppler vibrometers. In this article, we show that a proper arrangement of the experiment and the camera allows noncontact measurement of the characteristics of the main displacement mode (amplitude, frequency, and attenuation). An application is given for the analysis of structure damages after low-speed car impacts. The method is low cost, fast, and accurate, and it permits direct visualization and measurement of the movement of the vibrating body.