聚乙烯缓冲材料多自由度跌落包装系统优化设计

在测试基础上，依据粘弹性力学理论，建立发泡聚乙烯缓冲材料动态非线性本构模型，并成功识别了模型参数；应用此模型在一定高度跌落冲击下，建立了多自由度包装系统动力学方程；依据物品响应加速度小于许用值及材料用量最小化两个原则，进行多自由度系统缓冲包装优化设计并获得最优解；基于最优解结构尺寸，测试了发泡聚乙烯缓冲系统的加速度响应值，数值算例及试验的结果表明理论值与试验值的平均相对误差都在0.8%以内。利用此设计方法可有效地避免欠包装和过度包装,克服了最大加速度-静应力曲线不能设计多自由度缓冲包装设计的弊端

Optimization design of MDOF package cushioning system made of polyethylene

Based on drop shock test,nonlinear dynamics constitutive relation of polyethylene foam was established and the relenant parameters were identified successfully.The constitutive relation of the foam was used in the design of multi-DOF packaging system made of polyethylene foam,and the dynamics equation was constructed under the given drop height.Based on the criteria that the response acceleration of the items should be smaller than an allowable value and the material consumption of polyethylene should be minimal,the object function for optimization of the package cushioning structure was determined,and the optimization solution of multi-DOF package cushioning system was then obtained.The response accelerations of the packaging system were also measured.The results show that the relative errors between measured and calculated values of the response accelerations are less than 0.8% so that the model can be used to directly design package cushioning structure.Excessive or less packaging can be thus avoided.The method makes up the conventional design method of maximum acceleration-static stress curves be available in designing multi-DOF package cushioning system package.The method and process also provide reference to design other material package cushionings.