P. Fathi, Frattura ed Integrità Strutturale, 53 (2020) 457-473; DOI: 10.3221/IGF-ESIS.53.36 457 Focussed on Structural Integrity and Safety: Experimental and Numerical Perspectives Numerical and Experimental Analysis of Stacking Sequences Effects in Composite Mechanical Joints under Impact Loadings Pourya Fathi, Alireza Naddaf Oskouei, Khodadad Vahedi, Amin Moslemi Petrudi Department of Mechanical Engineering, Tehran University, Iran amin.moslemi2020@gmail.com, http://orcid.org/0000-0002-5928-0479 ABSTRACT. The paper deals with composite structures in the field of advanced and modern structures in engineering design and according to high specification of composite materials such as high strength to weight ratio use in various industries such as aerospace, marine. One of the most important fields that Researchers have paid less attention to that is to investigate the effect of stacking sequence on the strength of mechanical joints under impact loading. In view of changing the mechanical properties of composite materials by changing the arrangement of layers, in this study, the effect of different orientation of layers on the strength of pin joints in glass-epoxy composites under low-velocity tensile impact has been investigated. Using the Abaqus software and the finite element method, the impact simulation and the force applied to the mechanical joint were analyzed. To evaluate the simulations, the results of the finite element method have been compared with the experimental results. By observing the results, the introduced finite element model is well-considered and is well-matched with the result of the experimental dataset, which made it a valuable tool for predicting the strength of multi-layer composite materials under impact loadings. Using the results of the model, one can analyze the distribution and type of stress and strain in each layer of composite. KEYWORDS. Composites; Mechanical Joint; Joints Strength; Stacking Sequence; Tensile Impact. Citation: Fathi, P., Oskouei, A. N., Vahedi, K., Petrudi, A. M., Numerical and Experimental Analysis of Stacking Sequences Effects in Composite Mechanical Joints under Impact Loadings, Frattura ed Integrità Strutturale, 53 (2020) 457-473. Received: 17.05.2020 Accepted: 12.06.2020 Published: 01.07.2020 Copyright: © 2020 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. INTRODUCTION ue to the progress of the industry in the field of composites and the fact that composites have significant properties such as high resistance to weight ratio, researchers and experts are exploring various aspects of their application. In the field of mechanical engineering, composites are one of the most important topics, especially in the field of solids. Combining two or more materials together to be chemically separate and insoluble, the composite yield and structural properties of each compound are considered superior to each of its constituents alone. Due to this, Composite and metal alloy are different. Therefore, a composite is a combination of at least two separate materials with a specified cross-section between each constituent [1]. Composites have found wide application in the marine, aerospace, defense, automotive industries due to their advantages and properties. An example of the use of composites in the aerospace industry is shown in Fig. 1 [2]. Much work has been done to model and analyze the impact of low velocity impacts on composites and D