Damage Boundary Evaluation Approach For Multi-component Coupled Daily Chemicals Bottle With Pump Head

With the development of the e-commerce express industry,reasonable and effective packaging has attracted increasingly more attention.The traditional packaging dynamics theory evaluated the damage potential of shocks to product with only one critical component,however,most products are assembled from several components,which means the possibility of mistakes of packaging design based on the only one critical component.In this study,based on theoretical analysis and experimental verification,the shock response of packaging system with several critical components under the excitation of half-sine pulses was investigated,and the damage potential of shocks to one critical component may be transferred to other components with different packaging structures,which can be described by a newly proposed combined damage boundary curve.The concept was then verified by impacting the daily chemicals bottle with pump head,showing overall agreement.Moreover,the self-cushioning performance of the product was proposed,and the effect of the self-cushioning performance of the product on the shock response of packaged product was revealed.The main content of this study was constructed as follows:(1)Analysis of the shock response of multi-component coupled product packaging system.Taking a typical product packaging system containing two critical components as an example,the effect of packaging stiffness on the shock response of the components was studied.It was found that the damage potential of shock to critical components may shift from one to another with different packaging stiffnesses.Besides,through the analysis of the time domain response characteristics of the system,it was concluded that the damage of shock to components was decided by whose peak acceleration exceeds its fragility other than whose fragility was smaller.(2)Experimental study on impact damage of the typically multi-component coupled product.Through impact test of six kinds of daily chemicals bottle with pump head under halfsine pulse excitation,the effect of different postures on the damage form and impact strength was discussed.It was found that under different impact postures and different drop heights,the damaged parts of the samples were different.An index was proposed to quantify and comprehensively evaluate the damage,reflecting the impact strength properties of the samples.(3)The so-called combined damage boundary theory for multi-component coupled product was developed.Taking a linear packaging system containing two critical components as an example,a combined damage boundary concept was suggested considering the damage potential of shock shifting from one component to another.The traditional damage boundary theory suggested that the damage potential of shock to product always happens at the same critical component.However,for a multi-component coupled product system,the damage boundary of the product may happen at different critical components.Here,the daily chemicals bottle with pump head was dropped to verify the proposed combined damage boundary theory.(4)The self-cushioning performance of the product was firstly proposed.When the packaged product was subjected to external impact,the product could resist the external impact energy through its own deformation.Based on this,the drop impact dynamical equation considering the self-cushioning capacity of the product was established,and then the effect of the so-called virtual mass,the self-cushioning equivalent stiffness and the initial stiffness of typical nonlinear packaging materials on the peak acceleration response of packaged product was discussed by using numerical method,from which the self-cushioning performance of packaged product was characterized.