PSI - Issue 52

ScienceDirect Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2022) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2022) 000 – 000 Available online at www.sciencedirect.com Procedia Structural Integrity 52 (2024) 234–241

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© 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Professor Ferri Aliabadi Abstract Interface debonding is a common and harmful failure mode in the sandwich structure, and understanding the specific characteristics of interface failures is crucial. The modified crack surface displacement extrapolation (MCSDE) method is proposed in this paper to numerically solve the energy release rate (ERR) and mode mixity phase angle (PA) by using the relative surface displacement. The MCSDE method is proved accurate by applying the constant bending moment loading to the two arms of the double cantilever beam loaded by uneven bend moment (DCB-UBM) sandwich specimen. The impulse load in form of a step function is applied to investigate the fracture characteristic of the DCB-UBM specimen under dynamic loading. The result shows that the bending moment ratio (M R ) has a significant effect on the PA of the DCB-UBM specimen. Under the dynamic load, both ERR and PA will oscillate due to the influence of inertia. The degree of oscillation of ERR is higher than that of PA. The MCSDE method can accurately evaluate ERR and PA under static and dynamic loads. Fracture, Damage and Structural Health Monitoring Mixed Mode Fracture Mechanics Characterization of DCB-UBM Sandwich Specimen Under Dynamic Loading Chen Zhou*, Jian He, Yulin Wang College of Aerospace and Civil Engineering, Harbin Engineering University, Harbin 150001, China Abstract Interface debonding is a common and harmful failure mode in the sandwich structure, and understanding the specific characteristics of interface failures is crucial. The modified crack surface displacement extrapolation (MCSDE) method is proposed in this paper to numerically solve the energy release rate (ERR) and mode mixity phase angle (PA) by using the relative surface displacement. The MCSDE method is proved accurate by applying the constant bending moment loading to the two arms of the double cantilever beam loaded by uneven bend moment (DCB-UBM) sandwich specimen. The impulse load in form of a step function is applied to investigate the fracture characteristic of the DCB-UBM specimen under dynamic loading. The result shows that the bending moment ratio (M R ) has a significant effect on the PA of the DCB-UBM specimen. Under the dynamic load, both ERR and PA will oscillate due to the influence of inertia. The degree of oscillation of ERR is higher than that of PA. The MCSDE method can accurately evaluate ERR and PA under static and dynamic loads. Keywords: DCB-UBM sandwich specimen; MCSDE method; Impulse loading; Mode mixity; Mixed mode fracture. 1. Introduction The sandwich structure is typically made up of an upper and lower face sheet as well as a core in the middle. Compared with traditional metal structures, the sandwich structure is light in weight and high in strength, so it is widely used in aerospace (Sairajan et al. 2016), marine (Palomba et al. 2021), and other fields (Yin et al. 2018; Chu Fracture, Damage and Structural Health Monitoring Mixed Mode Fracture Mechanics Characterization of DCB-UBM Sandwich Specimen Under Dynamic Loading Chen Zhou*, Jian He, Yulin Wang College of Aerospace and Civil Engineering, Harbin Engineering University, Harbin 150001, China Keywords: DCB-UBM sandwich specimen; MCSDE method; Impulse loading; Mode mixity; Mixed mode fracture. 1. Introduction The sandwich structure is typically made up of an upper and lower face sheet as well as a core in the middle. Compared with traditional metal structures, the sandwich structure is light in weight and high in strength, so it is widely used in aerospace (Sairajan et al. 2016), marine (Palomba et al. 2021), and other fields (Yin et al. 2018; Chu

* Corresponding author. Tel.: +86 13114512686. E-mail address: zhouchen@hrbeu.edu.cn

2452-3216 © 2023 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Professor Ferri Aliabadi 10.1016/j.prostr.2023.12.024 2452-3216 © 2023 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Professor Ferri Aliabadi 2452-3216 © 2023 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Professor Ferri Aliabadi * Corresponding author. Tel.: +86 13114512686. E-mail address: zhouchen@hrbeu.edu.cn