Topology-Dependent Modeling Fidelity of Lattice-Reinforced UAV Leading-Edge Structures Under Bird Strike Impact

Lattice-reinforced thin-walled structures offer a promising means of improving impact resistance while maintaining structural efficiency; however, their detailed numerical simulation can become computationally expensive under high-rate loading conditions. This study investigates how lattice topology influences the fidelity of reduced-order beam element models for bird strike impact analysis. Three lattice topologies, BCC, Diamond, and Kelvin, are evaluated using low-fidelity beam element and high-fidelity solid element models under identical geometry, material properties, boundary conditions, and impact loading at 68.4 m/s. The comparison considers transient and residual displacement, total and component-level energy absorption, stress distribution, and computational cost. The results demonstrate that modeling fidelity is strongly topology-dependent and response-dependent. For the sparse BCC architecture, low-fidelity predictions agree closely with the high-fidelity reference, with peak displacement and total energy discrepancies of approximately 10% and below 5%, respectively. In contrast, Kelvin and Diamond topologies exhibit larger discrepancies, particularly in residual deformation and component-level energy redistribution. Notably, the magnitude and character of the fidelity discrepancy vary with topology and response quantity, indicating that a universal correction factor based on a single response metric is inappropriate. Despite these limitations, beam element models reduce computational time by 74-86% relative to their solid element counterparts. The results provide quantitative guidance for selecting modeling fidelity according to lattice topology and structural response quantity within the investigated bird strike configuration.