1 School of Material Science and Engineering, Nanchang Hangkong University, Nanchang 330063, China 2 Failure Analysis Center, AECC Beijing Institute of Aeronautical Materials, Beijing 100095, China
In order to explore the quantitative characterization method of non-oriented acrylic sheet fracture and the correlation between the fracture morphology of acrylic sheet and tensile temperature. The non-oriented acrylic sheet for aircraft was used as the research object. Firstly, the size and surface roughness of the mist region were measured by stereo microscope and 3D Laster Scanner(LEXT). Secondly, the fracture was measured by box counting method. Finally, the energy consumed by the rupture of the acrylic sheet to form the mist zone was estimated by two hypotheses and was related to the fractal dimension of the fractured mist zone. The results show that when the stretching rate is constant, the stretching temperature is raised from -55 ℃ to 60 ℃, the size of the fractured mist zone ${\bar I}$3 is increased from 1.257 mm to 4.978 mm, and the surface roughness ${\bar R}$a is reduced from 0.517 μm to 0.330 μm, the fractal dimension ${\bar D}$is increased from 1.357 to 1.579. The fitting degree factors of the fitting curves of the tensile temperature and the size, surface roughness and fractal dimension of the fracture foggy area are higher than 0.9, and there fitting degree of these curves are higher. Therefore, the morphological parameters of the tensile fracture of the acrylic sheet have a certain correlation with the fracture conditions, and the energy consumed in the formation of the mist region of the acrylic sheet is positively correlated with its fractal dimension.
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