纸板厚度方向的力学模型建立

目的理论推导纸板在受到z向压缩和弯曲时的本构模型。方法对纸板进行z向压缩时,用Ramberg-Osgood方程描述加载过程的应力-应变关系。根据纸板的内部结构特点,用多孔弹性材料模型描述卸载过程的应力-应变关系。基于对纸板弯曲时变形过程的分析,利用复合材料层板模型和纤维网络模型描述弯曲时纸板层应力-应变关系。结果该模型能描述纸板在厚度方向上的力学特性,为建立完整的纸板本构建模提供参考,同时为有限元模拟纸板厚度方向变形提供依据。

Establishment of Mechanical Model in the Thickness Direction of Paperboard Materials

Objective To derivate the paperboard constitutive model in the z-direction by compression and bending based on related literature and tests. Methods The stress-strain curve for z-compression was described by a Ramberg-Osgood function, and unloaded by a porous material model according to characteristics of the internal structure of the cardboard. The stress -strain relationship for band was described by composite laminates model and network model, and it was based on the paperboard of bending deformation processes. Results The model was able to describe the paperboard in the z-direction of the mechanical properties. It provided reference for the establishment of paperboard mold, and provided theoretical basis for finite element simulation of deformation in the z-direction of paperboard.