DIMENSIONIERUNG UND DURCHFÜHRUNG EINES ULTIMATE-LOAD TESTS DER FLÜGELSTRUKTUR DES HAP-ALPHA

Abstract

In the HAP (High Altitude Platform) project, the German Aerospace Center (DLR) is developing a solar-powered long-range aircraft, various payloads for Earth observation missions, the ground control station and operating concept. The mission conditions and objectives pose major challenges to the aircraft structure, especially with respect to lightweight design. This paper presents the dimensioning, the set-up and procedure of an Ultimate Load test of the HAP alpha wing structure. The wing, with an overall span of 27m, is divided in three wing sections, with the tubular wing spar being assembled from several segments for manufacturing reasons. The dimensioning is based on global (GFEM) and detailed finite element models (DFEM) considering numerous flight and ground load cases. Out of the load case envelope, two main test load cases are extracted, a pure torsion load test and a combined bending and torsion load case. In addition, stiffness tests are performed beforehand without and with wing covering. Due to the design phase, the tests are used for validation of the finite element models. It will be presented the test set-up, load application to the fragile structure, measurement equipment, the test procedure and results of the test.