A novel test method is proposed in this research for determining the tensile strength of rocks and geo-materials. Using a seesaw device, two diametral tensile forces are applied to the inner surface of a ring shape specimen and consequently the ring specimen is splitted along a plane normal to the direction of applied tensile loading. A suitable formulation was derived for determining the tensile strength value using the direct ring tension specimen tested with the seesaw device. The required shape factor for the suggested tensile strength relation was obtained from the finite element analyses of ring specimen with different inner and outer diameters. The practical ability of suggested direct tensile strength measurement method was examined by performing some tensile strength experiments on tuffite rock and it was found that the results obtained from this test method is in very good agreement with two other conventional indirect tensile strength testing methods namely the Brazilian disc and compressed ring tests. Suitable geometry (i.e. inner/outer diameter ratio) was also proposed for testing the ring specimen. In addition, the fracture patterns of direct and indirect ring specimens tested with different d_i/d_o ratios were simulated and predicted using the XFEM method.

在这项研究中提出了一种新的测试方法来确定岩石和土工材料的抗拉强度。使用跷跷板装置，将两个径向拉伸力施加到环形样品的内表面上，因此，环形样品沿垂直于所施加拉伸载荷方向的平面分裂。使用跷跷板装置测试的直接环张力试样，得出用于确定抗张强度值的合适配方。从不同内径和外径的环形试样的有限元分析中获得了建议的抗拉强度关系所需的形状系数。通过对凝灰岩进行一些拉伸强度试验，检验了建议的直接拉伸强度测量方法的实用能力，发现该测试方法获得的结果与另外两种常规的间接拉伸强度测试方法（即巴西）非常吻合盘和压缩环测试。还提出了合适的几何形状（即内/外径比）来测试环形试样。另外，用不同的试验方法测试了直接和间接环形试样的断裂模式使用XFEM方法模拟和预测d _i / d _o比率。