THREE DIMENSIONAL FINITE ELEMENT FRICTIONAL CONTACT ANALYSIS

• Main Authors: Shieh Chyuan-jau, 謝全釗
• Other Authors: Wen-Hwa Chen
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/08043070738266221016

博士 === 國立清華大學 === 動力機械工程學系 === 90 === This work presents a rigorous three-dimensional finite element frictional contact analysis procedure to analyze belt transmission systems, including the flat-belt, V-belt and continuously variable transmission (CVT) systems. The frictional contact behavior on the contact surface, which accounts for the power loss of the transmission systems and the wear of the belt, is investigated in detail. Based on the transformation matrix established for satisfying the contact conditions on the contact surfaces between the belt and pulleys, an incremental restricted variational principle with the centrifugal force term is introduced to model the angular speed effect of the transmission system operating at a constant angular speed. Then, the simultaneous algebraic equations for the finite element frictional contact analysis of the belt transmission system are formulated. To model the flexible property of the belt, the three-dimensional bar element and eight-node brick element are employed to simulate the tension member and rubber layer of the belt. For evaluating the contact traction, to improve the inaccuracy at the end zones of the contact area due to bending effect, the incremental Wilson displacement modes are added to the displacement approximation of the eight-node brick element. In addition, appropriate frictional contact and loading conditions are provided to simulate the physical contact phenomena between the belt and pulley. For an operating flat-belt transmission system, the angular speed loss between the driver and driven pulleys induced by the deformation of the belt and the frictional contact on the contact surfaces is analyzed. The effects of dynamic friction coefficient, traction coefficient and material properties of the flat-belt on the angular speed loss are also studied. The effects of angular speed and dynamic friction coefficient on the contact behavior of the flat-belt transmission system are presented as well. On the frictional contact analysis of the V-belt transmission system, the influences of dynamic friction coefficient on the normal and tangential contact forces, the deformation of the V-belt and the distribution of contact tractions occurred on the contact surfaces between the V-belt and pulley are thoroughly studied. Thus, the most possible position of wear at the edge of the V-belt cross-section can be observed. For the CVT system, the effect of angular speed on the frictional contact behavior between the V-belt and pulley flange is investigated. The friction angles of contact points along the edge of the V-belt cross section are also evaluated for various dynamic friction coefficients. The present work should be helpful for the estimation of wear properties and operation efficiency for belt transmission systems. Besides, the proposed three-dimensional frictional contact finite element procedure can be further applied to deal with the mismatched effect between the V-belt and pulley flanges which is caused by the distortion of V-belt cross section as the belt bends surrounding the pulley. The belt transmission systems with other types of belt, such as metal V-belt or toothed-belt, etc, are also worthwhile to be investigated in the future.