PSI - Issue 28

I.J. Sánchez-Arce et al. / Procedia Structural Integrity 28 (2020) 1084–1093 Sánchez-Arce et al. / Structural Integrity Procedia 00 (2019) 000–000

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5. Conclusions Numerical analysis of adhesively bonded has proven to be the most accurate method to predict joint strength when considering non-linear material properties. Current established numerical analyses require fine meshes to provide accurate results; however, large deformation analyses may require even finer meshes. The NNRPIM is a meshless method that does not require a previous mesh or uniformly distributed nodes; in addition, it allows large deformation analyses making it suitable to analyze adhesive joints, but its application still is in an early stage. To determine the suitability of NNRPIM for this application, the strength of adhesive joints with various L O was evaluated here. As a first stage, only linear elastic properties were used, and the predictions were compared against the FEM. The NNRPIM strength estimations were found similar to those obtained from the FEM. The maximum difference observed was 2.0% corresponding to the L O =25.0 mm. Correspondingly, differences between the stress distributions determined by the FEM and NNRPIMwere evaluated, the maximum difference observed correspond to the peak shear stress, being 6.6%. In this application, the NNRPIM method provided similar results, both in magnitude and pattern, to those obtained with the well-accepted FEM. Therefore, it can be concluded that the NNRPIM method is suitable for this application leading to further research applications such as DLJ and industrial applied joint geometries. Moreover, this research leads to further exploration of the use of elastic-plastic material models to achieve more accurate P max predictions regardless of L O or adhesive toughness. Currently, application of RPIM and NNRPIM methods in the elastic-plastic analysis of SLJ is being carried out; good results had been achieved with L O lower than 37.5 mm, but for the 50.0 mm strength prediction is still low. Further research work is being performed for improving the material models and yield criteria used with the method, which could improve the predictions. Acknowledgements The authors thank to the Ministério da Ciência, Tecnologia e Ensino Superior - Fundacão para a Ciência e a Tecnologia (Portugal) by the funding provided, as follow, under project MIT-EXPL/ISF/0084/2017 and ‘POCI-01 0145-FEDER-028351’. Additionally, the authors acknowledge the funding of Project ‘NORTE-01-0145-FEDER 000022’ - SciTech - Science and Technology for Competitive and Sustainable Industries, co-financed by Programa Operacional Regional do Norte (NORTE2020), through Fundo Europeu de Desenvolvimento Regional (FEDER). References [1] R.D. Adams, W.D. Wake, Structural Adhesive Joints in Engineering, Elsevier Applied Science Publishers LTD, Essex, England, 1984. https://doi.org/10.1007/978-94-009-5616-2. [2] P.A. Fay, History of Adhesive Bonding, in: R.D. Adams (Ed.), Adhes. Bond. Sci. Technol. Appl., Woodhead Publishing Limited, Cambridge, England, 2005: pp. 3–22. [3] L.F.M. da Silva, A. Öchsner, R.D. Adams, Handbook of Adhesion Technology, Springer-Verlag Berlin Heidelberg, 2011. https://doi.org/10.1007/978-3-642-01169-6. [4] C. Gui, J. Bai, W. Zuo, Simplified crashworthiness method of automotive frame for conceptual design, Thin-Walled Struct. 131 (2018) 324–335. https://doi.org/10.1016/J.TWS.2018.07.005. [5] L.F.M. da Silva, D.A. Dillard, B. Blackman, R.D. Adams, eds., Testing Adhesive Joints, Wiley-VCH Verlag & Co. KGaA, 2012. [6] R.D. Adams, N.A. Peppiatt, Stress analysis of adhesive-bonded lap joints, J. Strain Anal. 9 (1974) 185–196. https://doi.org/10.1243/03093247V093185. [7] A.D. Crocombe, Global yielding as a failure criterion for bonded joints, Int. J. Adhes. Adhes. 9 (1989) 145–153. https://doi.org/10.1016/0143-7496(89)90110-3. [8] T.M. Roberts, Shear and Normal Stresses in Adhesive Joints, J. Eng. Mech. 115 (1989) 2460–2479. https://doi.org/10.1061/(ASCE)0733-9399(1989)115:11(2460). [9] R.D. Adams, N.A. Peppiatt, Effect of poisson’s ratio strains in adherends on stresses of an idealized lap joint, J. Strain Anal. 8 (1973) 134–139. https://doi.org/10.1243/03093247V082134. [10] V.P. Nguyen, T. Rabczuk, S. Bordas, M. Duflot, Meshless methods: A review and computer implementation aspects, Math. Comput. Simul. 79 (2008) 763–813. https://doi.org/10.1016/J.MATCOM.2008.01.003. [11] B. V Farahani, J. Belinha, R. Amaral, P.J. Tavares, P.M.P.G. Moreira, Extending radial point interpolating meshless methods to the