Eduardo de Melo Pinto, Flávio Cardoso-Ribeiro, Fernando de Oliveira Moreira
DOI Number: N/A
Conference number: IFASD-2024-117
The analysis of aircraft loads during flight maneuvers plays a pivotal role in ensuring structural integrity, safety, design of lighter structures and more fuel-efficient vehicles. This
study focuses on a comparative analysis of internal load diagrams and flight parameters time histories for a flexible aircraft and its rigid-body counterpart, emphasizing the impact of structural flexibility on flight dynamics and loads during flight maneuvers. The research employs a dynamically-coupled formulation for the flexible model, considering small deformations and inertially coupled equations of motion. The aerodynamic loads are calculated with a quasi-steady VLM model, and the structural dynamics is represented by a linear FEM model. The rigid-body model is obtained by neglecting structural flexibility, setting the number of elastic modes to zero. To calculate the internal loads, the force summation method is employed. Three maneuvers from CS-25 specifications are simulated: the symmetrical unchecked and checked maneuvers, and the roll maneuver. For the unchecked and roll maneuvers, the flexible model exhibits a slightly slower response and reduced wing and horizontal tail loads compared to the rigid model. In the checked maneuver, the flexible model displays nuanced differences in flight dynamics and horizontal tail loads, computing higher absolute TMY values, and higher SLZ and BMX loads at the instant of maximum positive FZTH, while the rigid-body model presented higher absolute values of SLZ and BMX. Regardless of the obtained variations, the study emphasizes the importance of considering structural flexibility in analyzing flight maneuver loads and the need for more precise and efficient methods to address the evolving landscape of aircraft design.