Shock and Vibration Data Acquisition and Analysis for High Speed Planing Boats

摘要

The crew and passengers onboard US Navy Special Operations craft are exposed to high levels of shock and vibration which are hazardous to their health and impair their performance. The Naval Surface Warfare Center – Panama City developed a small, userwearable data collection system to record craft and human shock and vibration data during training operations. A principal feature of the data collection system is its minimal impact on training operations, including elimination of the need for engineers to be onboard. The time-synchronized data recording capability allows the investigation of the transmission of shock energy from the deck, through the seats, and into the human. The data collection system also includes audio and full-spectrum video photography of the crew members, with the video and dynamics data fully time-synchronized. rnThe combination of audio, video, and dynamic sensor data allows for a comprehensive understanding of the complex dynamic environment. The current industry standard for human injury resulting from dynamic environments is the ISO 2631 Part 1 and Part 5. However, the shock induced from high speed planing boats does not strictly conform to the types of shock and vibration represented in the standard. Therefore NSWC-PC has investigated several techniques for analyzing dynamics test data. Some of the methods currently used for dynamics and injury analysis include: RMS, amplitude statistics (e. g., amplitude histogram, 1/3 highest, and 1/10 highest), PSD, rise-time analysis, the Displacement Response Index, the ISO 2631 Part 1, and the ISO 2631 Part 5 shock and vibration standards. This paper will discuss the rationale behind each of these analysis techniques and their means of implementation.