The random vibration characteristics of packaged products under four vibration levels and three constraint modes were investigated.The FE method was applied to analyze response features of product packages with fixed constraint, and stresses and strains of carton box and pad.The results indicated that the response acceleration power spectral density (PSD) of products depends mainly on the excitation acceleration PSD in resonance area;the packaging has performances of bandpass and amplification;the resonance frequency of packaged products increases with enhancement of constraints;the peak of the resonance acceleration PSD of products under a fixed constraint is obviously bigger than those of products under unrestraint and an elastic constraint, respectively;resonance frequencies and acceleration PSDs of products obtained with the FE method agree well with those of tests;the peak of acceleration PSDs of products is sensitive to the damping coefficient of the system;the FE method provides an effective means for analysis and design of product packaging under random vibration environment.%实验研究了产品包装件在四种振动等级、三种约束方式下的随机振动特性,采用有限元法进一步分析固定约束方式下产品包装件的响应特性以及纸箱和衬垫的应力和变形情况.研究结果表明,产品的加速度响应功率谱主要取决于共振区域的激励加速度功率谱,包装起到了在共振区域的带通和放大作用.随着约束方式的加强,产品包装件共振频率增大,固定约束方式下的共振加速度功率谱峰值明显大于无约束和弹性约束方式下的共振加速度功率谱峰值.有限元计算得到的共振频率和产品加速度功率谱与实验结果较好吻合,产品加速度功率谱峰值对系统阻尼系数十分敏感.有限元法为物流随机振动环境作用下产品包装件的分析与设计提供了有效手段.
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