平压单瓦钙塑瓦楞纸板本构模型

Study on constitutive model of single-wall Calcium plastic composite corrugated cardboard under flat compression loadings

为得到由纸面板和钙塑瓦楞夹芯结构复合而成的钙塑瓦楞纸板的力学行为,基于单瓦钙塑瓦楞纸板平压准静态和碰撞冲击试验,得到并分析了钙塑瓦楞纸板准静态应力-应变曲线及半正弦脉冲激励下的应力-应变曲线,结果表明钙塑瓦楞纸板应力-应变曲线呈线弹性区域、波动式上升屈服区域和压实区域;对比准静态和动态应力-应变曲线可知,钙塑瓦楞结构几乎不受应变率的影响,这是由于钙塑瓦楞的材料特性决定的。根据测试数据的三个特征与考虑粘滞性的因素,建立了钙塑瓦楞纸板的静态、动态非线性本构关系,成功识别出模型中的参数。所用的碰撞冲击试验方法为表征缓冲材料的力学行为提供了一个新的方法,同时得到的动态模型可直接应用于考虑钙塑瓦楞复合纸板箱缓冲作用的产品跌落冲击响应与优化设计。

To explore mechanical performances of the singe-wall calcium plastic structure made out of two paper factsheets and a corrugated calcium plastic sandwich structure,quasi-static stress-strain curve was obtained by using universal testing machine,then dynamic stress-strain response was reached when composite cardboard subjected to half-sine accelerations pulse provided by vertical impact collision tester.The experimental stress-strain curves show that they exhibit linear elastic region up to a smaller strain,then reach extended plastic yield regime which moves in a fluctuation rising type,and finally follow densification phase.Comparing the two stress-strain curve at static and dynamic loadings,the effect of strain rate at this specific range on the compressive behaviors is not remarkable,which is due to the particular characteristics of calcium plastic materials.The phenomenological constitutive relationships of calcium plastic structure were presented by nonlinear mathematical functions,and verified against the experimental results.Vertical impact collision tester provides a new method for examining dynamic mechanical behaviors of cushioning materials under excitation of half-sine acceleration pulse,and the constitutive relationship can be used directly to design packaging structure when the cushioning effect of packaging container made from calcium plastic cardboard is considered.