Sensor calibration for calculation of loads on a flexible aircraft

Abstract

In order to reduce costs of operation, new aircraft designs make vast use of light, flexible, and slender structures to achieve higher payloads and improved fuel consumption. At the same time, in order to reduce the amount of flight testing required for the certification of a new aircraft, the use of simulation models for certification purposes increases constantly. These models must be validated based on real flight data, for which airplanes must be instrumented adequately. Nowadays the test setups available for strain sensor calibration are highly sophisticated and instrumented, but also complex, time-demanding and expensive. Therefore, the ability to provide cost effective methodologies will be of great benefit with regards to the often overlooked and ever growing flexible small aircraft market. The current paper focusses on the strain sensor calibration methodology for both strain gauges and Fiber Bragg Grating sensors. The methodology is presented with many details and illustrated using a real application to the DLR Discus-2c sailplane. Various practical pitfalls are discussed as well as the issue of selecting the “best” combination of sensors for the development of the local structural load models.