Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 52 8 2019 03 18 Experimental and Numerical Investigation of Second Mode of Failure in Unlike End Notch Flexure Samples Experimental and Numerical Investigation of Second Mode of Failure in Unlike End Notch Flexure Samples 2093 2106 3343 10.22060/mej.2019.15299.6089 FA Sattar Maleki Department of Mechanical Engineering, Quchan University of Technology, Quchan, Iran Atieh Andakhshideh Department of Mechanical Engineering, Quchan University of Technology, Quchan, Iran Alireza Seyfi Department of Mechanical Engineering, Quchan University of Technology, Quchan, Iran Journal Article 2018 11 17 Localized lamination using composites is one of the effective solutions to repair damaged metallic pipelines. The connection of composite repair to the metal substructure in this method is one of the most important design parameters. Therefore, deriving the important parameters at the junction will help engineers in designing and predicting the interlaminar crack initiation and propagation at the composite/metal interface. In this paper, to investigate the second mode of failure in this method, the strain energy release rate is calculated experimentally and numerically in a steel/composite bond. According to an experimental standard for calculating the second mode strain energy release rate, ASTM-D7905, experimental tests are accomplished for three symmetric and asymmetric unlike end-notched flexure specimens and a relationship for the thickness of each material to have symmetric specimens is proposed. To validate the thickness calculation relationship, the finite element modeling of unlike samples using virtual crack closure technique is used which indicates the good agreement of experimental and numerical results. Comparing the experimental results showed that the strain energy release rate of symmetric samples is more than asymmetric ones and about 1.6 times as large. Localized lamination using composites is one of the effective solutions to repair damaged metallic pipelines. The connection of composite repair to the metal substructure in this method is one of the most important design parameters. Therefore, deriving the important parameters at the junction will help engineers in designing and predicting the interlaminar crack initiation and propagation at the composite/metal interface. In this paper, to investigate the second mode of failure in this method, the strain energy release rate is calculated experimentally and numerically in a steel/composite bond. According to an experimental standard for calculating the second mode strain energy release rate, ASTM-D7905, experimental tests are accomplished for three symmetric and asymmetric unlike end-notched flexure specimens and a relationship for the thickness of each material to have symmetric specimens is proposed. To validate the thickness calculation relationship, the finite element modeling of unlike samples using virtual crack closure technique is used which indicates the good agreement of experimental and numerical results. Comparing the experimental results showed that the strain energy release rate of symmetric samples is more than asymmetric ones and about 1.6 times as large. https://mej.aut.ac.ir/article_3343_21c5bba1dd6aed9ab48c2b34c1a0adde.pdf