Estudo da tenacidade à fratura de juntas adesivas sob modo misto (I+II) através do ensaio MMB-Mixed Model Bending

• Autor(a) principal: Silva, Felipe Pereira da
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/7987
• topic: MMB-Mixed Model Bending; Bonded Joints; ARC 858; Cohesive Zone Models; ABAQUS; MMB-Mixed Model Bending; Juntas Adesivas; ARC 858; Modelos de Dano Coesivo; ABAQUS; CNPQ::ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA::MATERIAIS NAO METALICOS::MATERIAIS CONJUGADOS NAO METALICOS

The use of structural adhesives has been increasing in several fields of modern engineering, one of the main reasons for this growth is related to its properties when compared to other conventional methods of union. In this work, the behavior of adhesive joints under mixed loading (Mode I and Mode II) was studied by representation the MMB-Mixed Model Bending test, registered in ASTM D6671 / D6671M (Mixed Mode I-Mode II Interlaminar Fracture Toughness of Unidirectional Fiber Reinforced Polymer Matrix Composites). For the study, it was considered metal-metal test pieces with adhesion agent of thickness of 1.6mm and adhesive ARC 858 of thickness 0.9mm. The study object properties were mode I fracture toughness (GIc) and mode II fracture toughness (GIIc). The CBBM (compliance based beam method) methodology was applied to the experiment to obtain these fracture toughness. It is presented a mathematical model that is independent of the tracking of crack propagation, and the experiment only depends on the load P, monitored by the universal test machine and the deformations in mode I (δI) and mode II (δII), which are monitored through of two dials gauges. In this way, the effectiveness of the method used in the measurements is compared and the results of the experimental test are compared with the results of Neto (2017). In addition, with the experimental results of the MMB test associated with the properties of the ARC 858 adhesive, numerical analysis with the commercial software ABAQUS of the combined loading joints (JCC), L-shaped, provided by Neto (2017) . In this computational experiment, the results were compared between the experimental values of Neto (2017) with the present work. The values of the strength of resistance obtained through the numerical analysis, when compared with the experimental values, showed good agreement. Also, the values found for the MMB test are shown, approaching the values found by Neto (2017) for mode I and diverging to mode II.