Comparative Structural Assessment of Shell-Only, Simple Ribs, Honeycomb Core and Full-Solid Composite UAV Wings

Abstract

This paper reports a finite‑element-analysis (FEA)–driven redesign of a fixed‑wing UAV to improve stiffness‑to‑weight and ultimate strength using composite structures. Four internal architectures sharing an identical outer mold line are compared: (1) full-solid, (2) shell‑only (no internal fill), (3) simple ribs, and (4) honeycomb core. Using orthotropic laminate models, static and modal analyses are conducted under limit (2.5g) and ultimate (1.5×) load cases with a clamped root boundary. Results show the honeycomb core achieves the best overall structural performance at mid‑weight, while the simple ribs concept provides most of the stiffness gains with minimal mass penalty. The shell‑only configuration is lightest but too flexible, meanwhile the full-solid is overweight for the constant MTOW. The study provides a reproducible FEA workflow and quantitative metrics for UAV teams transitioning away from monolithic wings.