TY - JOUR
T1 - An experimental and analytical study of mode I fracture and crack kinking in thick adhesive joints
AU - Shivaie Kojouri, Ali
AU - Karami, Javane
AU - Kalteremidou, Kalliopi-Artemi
AU - Fan, Jialiang
AU - Sharma, Akash
AU - Vassilopoulos, Anastasios
AU - Michaud, Véronique
AU - Van Paepegem, Wim
AU - Van Hemelrijck, Danny
N1 - Funding Information:
The authors acknowledge funding under the Lead Agency scheme from the Research Foundation - Flanders (FWO Vlaanderen) through the project grant G031020\u202FN and the Swiss National Science Foundation (SNF) through the project grant 200021E_18944/1 with the title \u201CCombined numerical and experimental approach for the development, testing and analysis of thick adhesive joints in large wind turbine blades\u201D. The authors also acknowledge Sika Technology AG for providing materials and support.
Funding Information:
The authors acknowledge funding under the Lead Agency scheme from the Research Foundation - Flanders (FWO Vlaanderen) through the project grant G031020N and the Swiss National Science Foundation (SNF) through the project grant 200021E_18944/1 with the title \"Combined numerical and experimental approach for the development, testing and analysis of thick adhesive joints in large wind turbine blades\u201D. The authors also acknowledge Sika Technology AG for providing materials and support.
Publisher Copyright:
© 2024 The Authors
PY - 2024/9
Y1 - 2024/9
N2 - This study investigates the fracture behavior of thick adhesive joints manufactured with composite adherends and bonded with an epoxy-based structural adhesive common to the wind turbine industry. For that purpose, double cantilever beam specimens with an adhesive thickness of approximately 10 mm and different pre-crack lengths are manufactured and tested under mode I loading. Analytical approaches are compared to assess the energy release rate, including the simple beam theory, modified beam theory, compliance calibration method, and beam on an elastic and elastic-plastic foundation. In order to evaluate the applicability of the analytical approaches, an in-situ measurement method based on Digital Image Correlation is also employed to determine the energy release rate of the thick adhesive joints. The crack propagation angle is determined theoretically using the second-order crack kinking theory. A good correlation is observed between the theoretical predictions and experimental results. Furthermore, it is demonstrated that due to the T-stress, the crack tends to deviate from the middle of the joint and propagate towards the interface. By comparing different data reduction methods to evaluate the energy release rate of thick adhesive joints, recommendations for their fracture analysis are made, pinpointing the beam on an elastic and elastic-plastic foundation as the most suitable model.
AB - This study investigates the fracture behavior of thick adhesive joints manufactured with composite adherends and bonded with an epoxy-based structural adhesive common to the wind turbine industry. For that purpose, double cantilever beam specimens with an adhesive thickness of approximately 10 mm and different pre-crack lengths are manufactured and tested under mode I loading. Analytical approaches are compared to assess the energy release rate, including the simple beam theory, modified beam theory, compliance calibration method, and beam on an elastic and elastic-plastic foundation. In order to evaluate the applicability of the analytical approaches, an in-situ measurement method based on Digital Image Correlation is also employed to determine the energy release rate of the thick adhesive joints. The crack propagation angle is determined theoretically using the second-order crack kinking theory. A good correlation is observed between the theoretical predictions and experimental results. Furthermore, it is demonstrated that due to the T-stress, the crack tends to deviate from the middle of the joint and propagate towards the interface. By comparing different data reduction methods to evaluate the energy release rate of thick adhesive joints, recommendations for their fracture analysis are made, pinpointing the beam on an elastic and elastic-plastic foundation as the most suitable model.
KW - Mode I fracture
KW - Energy release rate
KW - J-integral
KW - Thick adhesive joints
KW - Crack kinking
KW - Wind turbine blades
U2 - https://doi.org/10.1016/j.compositesb.2024.111695
DO - https://doi.org/10.1016/j.compositesb.2024.111695
M3 - Article
VL - 284
SP - 1
EP - 16
JO - Composites Part B: Engineering
JF - Composites Part B: Engineering
SN - 1359-8368
M1 - 111695
ER -