Abstract:By adding cushions with designed oblique surfaces to MTS system and to split Hopkinson pressure bar(SHPB) device,a series of experiments were conducted to investigate the quasi static(strain rate 3?10-5 s-1) and dynamic(strain rate 50 and 100 s-1) responses of Shandong granite under combined compression-shear loading. Five oblique angles,i.e. 0°,15°,30°,45°and 60°,were investigated in the present study. The results showed that both normal and shear modules exhibited the strain rate effect and certain path-load dependency,which revealed the coupled compression-shear effect. The normal modulus was the most sensitive to the shear stress. The failure strength of granite exhibited strain rate effect and path-load dependency. Employing the Drucker-Prager(D-P) criterion model to simulate the failure surfaces of Shandong granite at different loading rates,the strain rate effects of strength parameters,e.g. the inner friction angle and inner cohesion,were analyzed. Digital imaging correlation(DIC) method was employed to systematically analyze the displacement field and strain field. The results showed that the process of dynamic compression and shear loading was controlled by the shear strain. For the rock specimens were compressed from quasi static loading to dynamic loading,the main cause of specimen deformation and failure were turned from the tensile strain to shear strain. All these were resulted from the non-uniformity of rock specimen.
马少鹏,周 辉. 岩石破坏过程中试件表面应变场演化特征研究[J]. 岩石力学与工程学报,2008,27(8):1 667-1 673.(MA Shaopeng,ZHOU Hui. Surface strain field evolution of rock specimen during failure process[J]. Chinese Journal of Rock Mechanics and Engineering,2008,27(8):1 667-1 673.(in Chinese))
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