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Researches on the three-dimensional size effect of indentation and fracture

Dr. SHE Chongmin

E-mail address: cmshe@nuaa.edu.cn

State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China

Interface delamination and arching of a ductile thin film on a hard substrate subject to microwedge indentation were investigated systematically using a three-dimensional finite element method [1]. A traction ®Cseparation law was introduced to simulate the cohesion and failure behavior of the interface between the film and the substrate. The effects of the interface strength, indenter tip length and film thickness on the onset and growth of interface delamination and film arching were analyzed[1,2]. It was shown that a two- dimensional to three-dimensional transition of stress state occurs during indentation, depending on the indenter length, indentation depth and film thickness and so on. Conditions for using two-dimensional and three-dimensional models were suggested. A Equivalent thickness conception based on the equivalent constraint principle was developed to analyze the 3D effects of crack question[3, 4].

References:
[1] She C., Zhang Y-W., Zeng K-Y., Engineering Fracture Mechanics. 2009, 76: 2272-2280.
[2] Chen, L., Yeap, K. B., She, C. M., Liu, G. R., Engineering Structures, 33(12), pp 3269-3278, 2011/12.
[3] She C., Zhao J., Guo W., International Journal of Fracture 2008. 151, 151®C160.
[4] Yu P., She C., and Guo W., International Journal of Solids and Structures. 2010, 47: 2123-2130.
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