Structural analysis of wing ribs obtained by additive manufacturing

Abstract

Purpose Additive manufacturing (AM) has emerged over the past years as a key technology in aircraft structural components’ manufacturing. This paper aims to describe the numerical analysis and experimental testing of five wing ribs with different 2D topologies manufactured with polylactic acid (PLA) using the fused deposition modeling technology. The main purpose is to determine the best wing rib topology in terms of strength, stiffness and mass. Design/methodology/approach Numerical analyses are performed using Ansys Workbench’s static structural analysis for two distinct loading cases. In the first loading, the chord-wise distributed load, resulting from wing lift, is replaced by two equivalent concentrated loads at the leading and trailing edges. This simplification allows the numerical results to be experimentally validated. The second loading has distributed loads applied on the upper and on the lower surfaces of the wing rib to produce a more realistic structural response. Experimental tests are performed with the first loading case to determine maximum displacement and failure loads of the wing ribs studied. SEM is used to analyze fracture surfaces. Findings From the five different PLA printed wing rib topologies studied, it is found that truss type configurations are the more structural efficient, that is, truss topologies exhibit better specific strength and specific stiffness. Additionally, the limiting factor in the design of these wing ribs is stiffness rather than strength. Originality/value The work identifies the kind of structural topologies that are best suited for 2D wing ribs obtained by AM and leads the way to more complex and more efficient structural layouts to be explored in the future using topology optimization coupled with simple Finite Element Analysis (FEA).