Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
Progressive Failure Analysis of Composite Lugs
Submission Author:
Marx Thezolin , SP
Co-Authors:
Marx Thezolin, Mauricio Donadon, Pedro Higino Cabral
Presenter: Marx Thezolin
doi://10.26678/ABCM.COBEM2021.COB2021-1732
Abstract
The design of composite lugs for primary structures in aeronautical applications is a challenging process, often requiring extensive experimental testing that impacts the costs and time necessary for the development of the part. This is further aggravated in highly loaded components where the use of thick laminates increases the complexity of the analysis. In this context, a methodology for the analysis and failure prediction of lugs in components manufactured with carbon fiber-reinforced plastics under static loading conditions is presented with the objective to provide a numerical tool for a more efficient design procedure. The preliminary sizing and laminate selection are initially investigated using a semi-analytical approach based on the modeling of the behavior of the laminate as described by the classical laminated plate theory, which is extended to include a stress concentration factor to account for the presence of the lug. This model is combined with a genetic algorithm using an elitist selection scheme to search for viable geometries and layups while considering the specific design requirements and restrictions. These initial solutions are then studied in more detail using a progressive damage model integrated with finite element analysis in Abaqus FE code. Simulations are carried out using an explicit dynamics analysis under quasi-static loading conditions where the lug is modeled with solid elements in which a progressive failure model was implemented as a user-defined material model. The progressive failure model allows the prediction of matrix cracking, fiber failure, and delamination at ply level by using the Chang-Chang failure criteria combined with the Brewer-Lagace failure criterion. Once one or more failure criteria are met, a time-step degradation procedure is used to degrade the stresses associated with the predicted failure modes. The progressive damage analysis methodology was verified using experimental results from the literature, where a fairly good agreement between predictions and experimental data was found. The complete methodology was then applied to a case study focusing on the replacement viability of a metallic brace in the landing gear of a narrowbody aircraft by an equivalent composite part.
Keywords
Composite Materials, Finite Element Analysis, Progressive Damage Analysis, Composite Lug Design
