摘要：针对多自由度缓冲包装产品设计中杆式结构部件在工作过程中容易发生损伤而引起系统失效问题,本文提出将产品主体假设为刚性，杆式结构处理成均匀分布的弹性体结构，进而建立刚性—弹性体的非线性耦合模型及运动微分方程，并运用差分方法进行求解，得到杆式易损零件非线性包装系统的数值解。算例结果表明:杆式易损部件的最大加速度位于杆的自由端，此处应力最小；最小加速度出现在杆的根部,此处应力最大。杆根部位置的最大应力是否超过弹性部件的比例极限成为产品失效的有效判据。

Abstract: The critical components of bar type in muti-freedom cushioning packaging products were likely to damage and cause system failures during the work, so this paper proposed that the item of cushioning packaging products were assumed to be rigid components, the critical components of bar type were processed into uniform and elastic parts, and nonlinear coupling dynamics models between the critical component and item were established as well as motion differential equations. The results of nonlinear cushioning packaging system were obtained by difference method. It demonstrated that the maximum acceleration of the bar component occured at its free end, whose stress was minimum. The bar end of the critical component had the maximum stress and minimum acceleration. Whether the maximum stress of the bar was beyond the proportion of elastic components was an effective parameter to determine whether the item lose its functions.