Abstract: In order to verify contact model and parameter rationality for structured sand in discrete element simulation, a set of apparatus for specimen preparation and tests on contact mechanical behaviors of idealized hemispherical bonded granules are designed. Throughout the specimen preparation devices, two aluminum hemispheres with the same size were cemented together by adhesive in a size-controlled mode. Then, a series of tests were conducted, including tension test, compression test, shear test, bending test and torsion test, using secondary loading devices. The results show that the apparatus are able to investigate the contact mechanical behaviors of two bonded hemispheres. The consequences are in good agreement with those extracted from the achievements of 2D tests in references. The peak shear force, bending moment, torque of two bonded hemispheres increase to a peak value with the normal force firstly, and then decrease with the normal force. In addition, the critical normal forces in different loading conditions are almost the same.

Key words: discrete element method, bonded granules, three-dimensional contact, experimental study