Abstract: In order to solve the precision machining problems of complex curved surfaces with soft-consolidation abrasives pneumatic wheel, a soft-consolidation abrasives dilatancy analysis model was proposed. The influences of dilatancy effect on the material removal characteristics of the workpieces were studied by the microscopic angle of view as the starting point. According to the dilatancy effect analysis of abrasives, the mathematical model of the porosity and the damping coefficient of the bonded abrasive systems was established, and the relationship between the void ratio and the average stress was also combined to obtain the stress equation of the contact surfaces of the abrasives. A soft-consolidation abrasives material removal model was established. The influences of the dilatancy effect on the contact forces was verified by the PFC3D simulation and the force sensor as the force measuring device. The contact stress may be changed by the adjustment of the damping coefficient of the abrasives binder. The results of finishing tests show that the binder damping coefficient may be increased to improve material removal effectivess of the surface molds according to the law of dilatancy effect. In the same processing time, the damping coefficient increases about 5.0×105, the material removal amount increases nearly 31.91%, the surface mold roughness decreases nearly 32.34%, and the workpiece scratches may be significantly reduced.

Key words: precision machining of curved surface, soft-consolidation abrasives, dilatancy effect, material removal

摘要： 针对软固结磨粒群气压砂轮复杂曲面精密加工问题，提出了一种软固结磨粒群剪胀分析模型，并以微观视角为切入点研究气压砂轮软固结磨粒群的微观剪胀效应对被加工件材料去除特性的影响规律。基于磨粒群剪胀效应分析，建立了孔隙率与黏结磨粒系统阻尼系数的数学模型，结合孔隙比与平均应力的关系，推导了磨粒群作用接触面的应力方程，建立了发软固结磨粒群材料去除模型。通过PFC3D仿真和力传感器测力设备验证了剪胀效应对接触力的影响规律。光整加工试验结果表明，可根据剪胀效应的规律来提高黏结剂阻尼系数从而提高曲面模具材料的去除效果，相同加工时间内，阻尼系数提高约5.0×105，材料去除量累计提高近31.91%，曲面模具的粗糙度降低近32.34%，工件划痕明显减少。

关键词: 曲面精密加工, 软固结磨粒群, 剪胀效应, 材料去除