将大理岩制备成圆盘试样及半圆盘试样,同时在试样的中心预制一条一定倾角的裂隙,通过变换裂隙倾角制备出不同几何形状的断裂韧度实验试样.基于不同的断裂韧度实验,获取了BD(圆盘试样)实验及SCB(半圆盘试样)实验在不同裂隙几何布置条件下的断裂韧度,分析几何因素对断裂韧度结果的影响.通过分析实验结果可得:实验的几何尺寸及实验加载方式对裂隙的断裂韧度、裂隙起裂角及裂隙的扩展路径有较大的影响;同时,BD实验的断裂韧度强度比SCB实验断裂韧度强度大,并且传统的MTS断裂准则不能很好描述不同裂隙倾角下SCB及BD实验断裂韧度的实验结果,而采用GMTS准则能够很好地预测Ⅰ、Ⅱ型混合断裂韧度实验结果.%The specimens of marble and semi disc were prepared,and a certain inclined fracture was preformed at the center of the specimen.The fracture specimens with different geometries were prepared by changing the dip angle of the fracture.Based on different experiments of fracture toughness,BD(disc specimens) test and SCB(semi disc specimen) fracture toughness in different fracture geometrical arrangement were obtained under the different conditions of experiment,the influence of geometrical factors on fracture toughness results were also analyzed.By analyzing the experimental results,it can be concluded that the size of the experiment and the mode of loading have a great influence on the fracture toughness,the crack initiation angle and the fracture propagation path.At the same time,the fracture toughness strength of BD experiment is larger than that of the SCB experiment,the experimental results of SCB and BD in the experiment of fracture toughness and fracture criterion of traditional MTS is not a good description of the different fracture angle.The GMTS criterion can well predict the experimental results of mixed fracture toughness of Ⅰ and Ⅱ type.
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