大直径菲涅尔透镜模具加工机理

Large Diameter Fresnel Lens Mold Machining Mechanism

针对大直径菲涅尔透镜模具的加工难题,基于有限元仿真软件ABAQUS和模态实验方法对大直径菲涅尔透镜模具切削过程加工机理进行分析.介绍了菲涅尔透镜设计及模具加工原理,结合材料本构关系、材料失效准则等,建立正交切削二维模型,得到仿真切屑,与模态实验得到的切屑进行对比,验证了仿真切削模型的可行性.研究了切削速度、进给速度对切屑形成过程的影响.研究结果表明:在H62黄铜模具加工过程中,材料强度和塑脆性对切屑形态产生重要影响,随着变形速度的提高,材料强度提高,材料塑性降低,切屑的演化过程依次分为带状切屑、锯齿切屑、单元切屑.

Aimed at the problem of large diameter Fresnel lens mold machining, this paper analyzed the large diameter Fresnel lens mold machining mechanism based on the ABAQUS finite element simulation software and modal test methods. The design and mold machining principle of Fresnel lens were introduced. Combined with the material constitutive relation and material failure criteria, a two-dimensional orthogonal cutting model was established and the chip derived from the simulation was compared with the chip from modal test, with a consequent verification of the feasibility of simulation chip model. The simulation contributes to an investigation into the effects of the cutting speed and feed on chip formation process. Results show that the material strength and plastic brittle have significant impact on chip morphology in the H62 brass mold processing, the material strength is improved with the increase of strain rate, and the evolution process of the chip can be divided into： ribbon cuttings, serrated chips, and cell chips.