254
ABSTRACTS box), rectangular or annular shear plate, vane shear apparatus and others have been usually used. Rectangular or annular shear plate and vane shear apparatus have an advantage that they can be used in field. In this study, m a n y factors which influence the shear properties measured by vane shear test are considered based on the results of shear tests. The shear properties measured by vane tests are c o m p a r e d with those by direct shear test (shear box) and unconfined compression test, and the differences of shear properties a m o n g these tests are discussed. Further, anisotropic characteristics of the strength of the clay samples used are considered. (Dept. of Civil Engineering, National Defense Academy, 1-10-20
Hashirimizu, Kanaga wa, 239, Japan.) 10. MASANORI KITANO and MUNEYUKI TOKITA. Study on interaction between rigid wheel and soil. This p a p e r presents the analysis and prediction of the interaction between rigid wheel and terrain soil. Numerical analysis has been conducted by the finite element method ( M A R K program), and tests of a rigid wheel at various slip conditions on dry loose sand are executed. As a result, it was found that the values calculated by FEM coincide with the experimental results, and the FEM analysis is useful to disclose the constitutive interaction and traction mechanism between rigid wheel and soil. (Dept. o£Mechanical
Engineering, National Defense Academy, Yokosuka, Kanagawa, 239, Japan.) 1t. KOJI OGAKI. A new concept of modeling the phenomena occuring under crawler and predicting its tractive performance. A new concept of theoretical prediction of tractive performance by relating contact stress, soil deformation and soil stress under crawler on soft soil. (Terramechanics
Research Division, Technical Center, Komatsu Ltd., 1200 Manda, Hiratsuka. Kanaga wa, 254, Japan.) 12. TATSURO MURO and YOSHICHIKA MATSUNAGA. Wear characteristics of surface coating for rock engaging tool of construction machinery. Abrasive wear tests for parent metal of rippertips, with 4 kinds of thermal sprayed metal and 2 kinds of welded metal have been executed under high contact pressure up to 39.2 MPa against granite in the dry and submerged states. The a m o u n t of wear of metal is expressed as an exponential function of contact pressure. The amount of metal wear for high contact pressure in the dry state is larger than that for the submerged state, because of modification and softening of the metal due to high frictional temperature. Also the wear a m o u n t of metal decreases with the increment of initial hardness at low contact pressure, and it decreases with the increase of softening resistance due to tempering at high contact pressure. As the welding metal including V, Nb and WC has a high initial hardness and a softening resistance on tempering at high contact pressure, its wear resistance in the dry or submerged state is the highest of all surface coatings.
(Faculty of Engineering, Ehime University, 3 Bunkyo-cho, Matsuyama. Ehime. 790, Japan. ) 13. NOBUTAKA ITO, MASAYOSHI NAKATA, KAZUHIRO NODA and TAKAYUKI ISOGAI. Practical method of reducing the resistance of the tracked vehicle under turning motion. A practical method of reducing the resistance of a tracked vehicle to turning or steering motion was discussed.