Flight Test Applications of an Improved Operational Load Monitoring Device
- PDF / 3,505,309 Bytes
- 14 Pages / 595.276 x 790.866 pts Page_size
- 76 Downloads / 255 Views
ORIGINAL PAPER
Flight Test Applications of an Improved Operational Load Monitoring Device Chan Yik Park1 · Myung‑Gyun Ko1 · Sang‑Yong Kim1 · Jae‑Seok Ha1 Received: 19 November 2019 / Revised: 21 January 2020 / Accepted: 16 March 2020 © The Korean Society for Aeronautical & Space Sciences 2020
Abstract This paper introduces a load monitoring device and its flight test applications for military aircraft. The device can digitize and record signals from optical fiber sensors and strain gauges. Some key flight parameters can be simultaneously recorded in the device, which is connected to an aircraft data bus cable. The device was installed on a low-speed aircraft and multiple sensors including fiber optic sensors and strain gauges were surface bonded on certain major structures. A total of 40 flight tests were conducted over 2 years. The recorded signals and parameters were successfully analyzed and reviewed to measure strains and vertical landing speeds and to estimate structural loads for over 200 flight hours. Structural load spectra were also obtained using the developed load monitoring device and compared with military specification and design spectra. Keywords Aircraft structure · Optical fiber sensor · Load spectrum · Fatigue
1 Introduction There is a strong interest in measuring actual loading environment as experienced by aircraft in operation. The military aviation community generally accepts operational load monitoring programs to achieve structural integrity throughout the entire life cycle of aircraft. The usage (or fatigue) monitoring enables the operational load monitoring devices to ensure safe and economical utilization of military aircraft structures. In fact, the requirement for usage monitoring is mandated by military specifications [1, 2]. JSSG-2006 [1] specifies that a data acquisition system shall be capable of recording the operational usage data of the airframe structure. The data acquisition system shall interface with the air vehicle systems and record the required data within the specified accuracies. Using the data acquisition system, the load/ environment spectra survey (L/ESS) [2] and/or individual aircraft tracking (IAT) [2] shall be conducted. L/ESS is one of the aircraft structural integrity program (ASIP) activities, which is used to obtain operational usage data. The data are utilized to update or confirm the original design spectrum. * Chan Yik Park [email protected] 1
3rd Directorate, 7th R&D Institute, Agency for Defense Development, Yuseong, P.O. Box 35, Daejeon 34186, Republic of Korea
The design spectrum is typically developed to establish the distribution, frequency, and sequencing of the operational loads that the aircraft will experience and is based on the design service life during the aircraft development phase. A 20% valid data capture rate of the fleet usage data is generally accepted for the L/ESS. The IAT is utilized to obtain operational usage data that can be used to adjust maintenance intervals on individual aircraft by a tail number. All force aircraft sha
Data Loading...
