PSI - Issue 56

Alexandru Isaincu et al. / Procedia Structural Integrity 56 (2024) 167–175 Alexandru Isaincu / Structural Integrity Procedia 00 (2019) 000 – 000

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materials. A higher thickness of the material will tend to flatten the curve around the average value. Considering the plain strain theory for the fracture toughness, an increase in thickness should provide lower values. For this type of materials, an increase in thickness will be followed by a differential change in material properties at different orientations (check Table 1 for values). Therefore, there is an inconsistent decrease in fracture toughness when comparing the results obtained for 2.0 mm and 3.2 mm. • The trend of the fracture toughness is to increase with the increase in orientation angle. This aspect occurs regardless of thickness. The orientation effect has a substantial contribution for the specimens with 2.0 mm thickness, in comparison with the 3.2 mm thickness specimens. This remark is especially visible for PPS GF40. The values obtained at 0° and 45° orientations are particularly similar. • As a general tendency, by increasing the specimen thickness, the amount of anisotropy (K Ic,90 - K Ic,0 ) is decreasing for both materials. Acknowledgement The work leading to this paper was partially supported by InoHubDoc project POCU/993/6/13/153432 and by the European Union's Horizon 2020 research and innovation program (H2020-WIDESPREAD-2018, SIRAMM), under grant agreement no. 857124. Results were disseminated in the SIRAMM project, final conference SIRAMM 23 in Timisoara, Romania. Special acknowledgement to the Solvay Group for providing the two materials and support. Recognition is also extended to Vitesco Technologies company for support in specimen elaboration. References Amjadi, Mohammad, and Ali Fatemi. 2020. “Tensile Behavior of High -Density Polyethylene Including the Effects of Processing Technique, Thickness, Temperature, and Strain Rate.” Polymers 12(9). Bernasconi, A., P. Davoli, A. Basile, and A. Filippi. 2007. “Effect of Fibre Orientation on the Fatigue Behaviour of a Short Glass Fibre Reinforced Polyamide- 6.” International Journal of Fatigue 29(2): 199 – 208. Friedrich, K. 1985. “Microstructural Efficiency and Fracture Toughness of Short Fiber/Thermoplastic Matrix Composites.” Composites Science and Technology 22(1): 43 – 74. Fu, Shao Yun, Chee Yoon Yue, Xiao Hu, and Yiu Wing Mai. 2001. “Characterization of Fiber Length Distribution of Short -Fiber Reinforced Thermoplastics.” Journal of Materials Science Letters 20(1): 31 – 33. Garcia-Manrique, J., D. Camas-Peña, J. Lopez-Martinez, and A. Gonzalez- Herrera. 2018. “Analysis of the Stress Intensity Factor along the Thickness: The Concept of Pivot Node on Straight Crack Fronts.” Fatigue and Fracture of Engineering Materials and Structures 41(4): 869 – 80. Hiroshi Tada, Paul C. Paris, and George R. Irwin. 2000. “Stress Analysis Results for Common Test Specimen Configurations.” In The Stress Analysis of Cracks Handbook, Third Edition , ASME Press, 39 – 80. Holmström, Petter Henrik, Odd Sture Hopperstad, and Arild Holm Clausen. 2020. “Anisotropic Tensile Behaviour of Short Glass -Fibre Reinforced Polyamide- 6.” Composites Part C: Open Access 2: 100019. Isaincu, Alexandru, Dan Micota, and Liviu Marsavina. 2022. “On the Fracture Toughness of PPS and PPA Reinforced with Glass Fiber.” Procedia Structural Integrity 41(C): 646 – 55. https://doi.org/10.1016/j.prostr.2022.05.073. Karger- Kocsis, J., and K. Friedrich. 1987. “Microstructural Details and the Effect of Testing Conditions on the Fracture Toughness o f Injection Moulded Poly(Phenylene- Sulphide) Composites.” Journal of Materials Science 22(3): 947 – 61. Kfouri, A. P. 1996. “CRACK EXTENSION UNDER MIXED -MODE LOADING IN AN ANISOTROPIC MODE-ASYMMETRIC MATERIAL IN RESPECT OF RESISTANCE TO FRACTURE.” Fatigue & Fracture of Engineering Materials & Structures 19(1): 27 – 38. https://onlinelibrary.wiley.com/doi/10.1111/j.1460-2695.1996.tb00929.x. Limited, Woodhead Publishing. 2012. “Fracture Toughness Properties of Aerospace Materials.” Introduction to Aerospace Materials : 454 – 68. Micota, Dan, Alexandru Isaincu, and Liviu Marşavina. 2021. “Experimental Testing of Two Short -Fiber Reinforced Composites: PPA-GF33 and PPS- GF40.” Material Design and Processing Communications 3(6): 2 – 8. Nelson, Patricia Kim, Victor C. Li, and Toshiro Kamada. 2002. “Fracture Toughness of Microfiber Reinforced Cement Composites.” Journal of Materials in Civil Engineering 14(5): 384 – 91. Ramirez, F. A., L. A. Carlsson, and B. A. Acha. 2009. “A Method to Measure Fracture Toughness of the Fiber/Matrix Interface U sing the Single Fiber Fragmentation Test.” Composites Part A: Applied Science and Manufacturing 40(6 – 7): 679 – 86.