Title: Evaluation of Sandwich Ramp-Down Features under Torsional Loading Conditions

Authors: Waruna Seneviratne, John Tomblin, and Vishnu Saseendran

DOI: 10.33599/nasampe/s.22.0821

Abstract: Ramp-down features are widely utilized in sandwich composite-based control surface panels such as rudders and elevators. These control surfaces invariably undergo a combined bending and torsional loading. Reliable damage characterization techniques must be employed for certification as well as to ensure the continued structural integrity of these panels. The critical feature in a sandwich ramp region is the ramp root area. Currently, failure modes in these features are investigated using test methodologies that subject the test articles to either pure tensile, compressive, or bending loads. To identify weak design features with the aid of a test methodology that introduces complex loading scenarios, in this work, failure modes were experimentally investigated under two distinct types of loading: pure torsion and a combined torsion + bending load. The applied loads are representative of aircraft control surface loads. This will also facilitate the industry in expanding their design tool with realistic-complex load cases. The influence of mid-ramp distance under both loading conditions was also compared. In particular, emphasis was laid on damage initiation and subsequent progression at the ramp root region. Experimental observations were correlated with a 3-D finite element model, which was also compared against the tensile load case. The unique approach presented here paves way for the establishment of robust evaluation practices of sandwich ramp down features under complex and realistic loading conditions.

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Conference: SAMPE 2022

Publication Date: 2022/05/23

SKU: TP22-0000000821

Pages: 18

Price: $36.00