胶印机中印刷压力分布的有限元仿真

Finite Element Simulation for Printing Pressure Distribution within Offset Press

目的揭示胶印机中印刷压力分布的函数规律,为胶印机设计和印刷质量控制提供参考依据。方法选用Mooney-Rivlin模型作为橡胶材料本构模型,在MSC.Patran中建立胶印机印刷滚筒与橡胶层接触挤压的有限元仿真模型。以MSC.Marc为求解器,对有限元模型进行集材料非线性、几何非线性和边界条件非线性等3种因素于一体的有限元分析。利用最小二乘法拟合有限元节点处的接触应力计算结果。结果经过计算,某型胶印机的平均印刷压力为0.548~0.643 MPa。结论在压印接触区域中,橡胶层外表面法向接触应力的分布函数为高斯函数,且平均印刷压力可通过高斯函数的二重积分求出。

The work aims to unveil the distribution function law of the printing pressure within offset press to provide a reference basis for the offset press design and the printing quality control. Mooney-Rivlin model was taken as rubber material constitutive model, and the finite element model was established in MSC.Patran to simulate the contact between printing cylinder of offset press and rubber blanket. With MSC.Marc as the solver, the finite element analysis of the model was performed. The finite element analysis was integrated with three nonlinear factors, i.e. nonlinearity of material, geometry and boundary conditions. The contact stress calculations at the finite element nodes were fitted by the least square method. By calculation, the average printing pressure of an offset press was 0.548～0.643 MPa. In the pressing contact area, the distribution function of the normal contact stress on rubber blanket＇s outer surface is Gaussian function, and the average printing pressure can be obtained by double integral of Gaussian function.