Numerical Simulation for Calculating the Tensile Strength and Fracture Toughness Based on Different Grain Sizes

doi:10.12068/j.issn.1005-3026.2017.06.021

Abstract

Abstract: Three-point-bending tests on three kinds rock samples of grain sizes 1.02mm(fine grained)， 2.12mm (medium grained) and 3mm(coarse grained) with different notches are numerically performed by RFPA-DIP version to simulate the failure process compared with experimental results in laboratory. A simple fracture model is established， linking fictitious crack to the average aggregate size so that the rock specimen and fictitious crack formation can be considered together. Maximum loads of three-bending-point tests with different initial notches containing different tensile strength and fracture toughness are analyzed. The concept of fractal dimension is introduced to characterize the grain size distribution. It is concluded that the fractal dimension decreases with the increase of grain size， and the rock samples with smaller fractal dimension correspondingly have smaller tensile strength and fracture toughness.

Key words: grain size, fracture toughness, tensile strength, fictitious crack model, three point bending test

CLC Number:

TU45

YU Miao， ZHU Wan-cheng， YU Yong-jun， YU Qing-lei. Numerical Simulation for Calculating the Tensile Strength and Fracture Toughness Based on Different Grain Sizes[J]. Journal of Northeastern University:Natural Science, 2017, 38(6): 864-868.

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