Design And Reliability Analysis Of Wood Packaging For Isolation Switch Module

With the wide application of gas insulated substation appliances,meanwhile,the problem of transportation and packaging is becoming more and more serious.This paper takes the isolation switch module as the research object,on the one hand,to solve the current transportation packaging problems,on the other hand,to explore a more appropriate design method for enterprises.Firstly,based on the theory of transport packaging,the fragility of the product was calculated by analogy and empirical formula.In addition,the unfavorable factors to the package in different circulation links were analyzed.The properties of three plywood materials with different thickness(6mm,9mm and 12mm)were tested,and the elastic modulus and static strength values of the longitudinal and transverse lines for each thickness were obtained.Besides,the preliminary design of packaging includes outer packaging,pallet,upper support,lower support and chemical protection.Secondly,the maximum deformation and stress results were calculated by theoretical and simulation analysis of the pallet.Based on the calculation,the maximum stacking layers of the package were obtained,and load values of the actual stacking were determined.Then deformation and equivalent stress of the product and packaging structure were acquired by finite element analysis.Likewise,the load value of simulation was got through the stress analysis of the fork lift process.The deformation and equivalent stress of bottom sheet of packaging box were obtained through analysis.Based on the above results,the stress value of the structure under different analysis conditions is less than the allowable value of the material,which meets the design requirements.The groove depth,side panel position and side panel proportion of the lower support were optimized by orthogonal test and finite element method,and a set of optimum matching parameters were obtained.Thirdly,dynamic analysis and research were carried out.The actual transportation process can consider the package as a two-degree-of-freedom system for analysis,and the theoretical system response expression can be got by mathematical derivation.The first six natural frequencies and vibration modes of the package were obtained by modal analysis of the package.Moreover,the modal results were evaluated from three aspects:theoretical value,self-excitation of truck and road condition.Random vibration simulation analysis was carried out,referring to the PSD curve of highway transportation grade II in the GB.The vertical stress and acceleration response values of the package were received by finite element analysis,which verified the dynamic reliability of the package.Finally,based on reliability theory,the expression of packaging reliability was derived from the concept of reliability.Similarly the mathematical expression of packaging reliability was derived from the concept of generalized impact load.The influence of fragility,circulation environment and transport time on packaging reliability was discussed.Also the randomness of fragility and circulation environment in current packaging design were sorted out and analyzed.Furthermore,corresponding determination methods were given.The influence of reliability index on packaging cost,failure cost and total cost was studied,and the solution procedure of the best reliability index was given by non-linear programming analysis method.Based on the above research,packaging design process can be optimized by using packaging reliability expression and best reliability index.It provides reference value for the subsequent development of packaging design technology.In summary,after the design of transport package for isolator module was completed,the static and dynamic analysis of the package was carried out,and the support structure was optimized by orthogonal test combined with finite element analysis,which provides reference for the packaging design of other modules.And based on the reliability theory,perfect the current packaging design process,which is conducive to the development of packaging design technology in enterprises.