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利用线弹性断裂力学的柔度法标定技术,建立了用直切槽巴西圆盘(CSTBD)试样确定岩石拉伸弹性模量的方法。采用三维等参边界元法对CSTBD试样几何进行标定,获得了仅依赖于试样几何的无量纲弹性柔度E′CsB,其中B是已知试样厚度,Cs是弹性柔度,E′是待定的拉伸弹性模量,通过试验测得Cs就可确定出E′。对取自四川某地灰岩进行了两种不同尺寸CSTBD试样的弹性柔度测试,进而计算出岩石弹性模量。结果表明,用建议方法计算出岩石弹性模量与按照ASTM标准进行单轴拉伸试验所获得的拉伸弹性模量比较,二者吻合较好。在试验中尺寸效应不明显。此方法还能够获得岩石断裂韧度KIc。
Using the method of flexibility method of linear elastic fracture mechanics, a method of determining the tensile elastic modulus of rock by using a straight grooved Brazilian disc (CSTBD) specimen was established. The three-dimensional isoparametric boundary element method was used to calibrate the CSTBD sample geometry. The dimensionless elastic compliance E’CsB that depends on the geometry of the sample was obtained only. B is the known sample thickness, Cs is the elastic compliance, E ’ Is to be determined tensile elastic modulus, measured by the test Cs can be determined E ’. The elastic compliance test of CSTBD samples from two limestone samples collected from a certain place in Sichuan Province was conducted to calculate the rock elastic modulus. The results show that the calculated elastic modulus of rock and the tensile elastic modulus obtained by uniaxial tensile test according to ASTM standard are in good agreement with each other. In the experiment the size effect is not obvious. This method is also able to obtain rock fracture toughness KIc.