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The Influence Ofpre-compression Ratio Ondynamic Static Cushioning Performa Nce Of Honeycomb Paperboard

Posted on:2013-01-08Degree:MasterType:Thesis
Country:ChinaCandidate:H WangFull Text:PDF
GTID:2211330371964791Subject:Industrial Engineering
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Honeycomb paperboard material has been used in many fields widely, such as aerospace, transportation, furniture and construction, with the significant advantages, light weight, high strength and recyclable. In recent years, some electric cars, car accessories and home appliance enterprise have tried to use honeycomb paperboard (HCB) to package their products, but unique mechanical characteristics for HCB, a peak stress shown on its compression curve, the cushioning performance of HCB is limited before the peak and material's irreversible deformation will lose the protective function when more than this peak, HCB and protect products effective only under the deformation controllable and energy absorption excellent state, it has not been used in packaging field as well as traditional foam buffer material.According to the actual problems resulted in packing product with HCB, first, this paper analysed the mechanical performance of HCB under original state, and proposed the concept of effective cushioning state, then discussed the mechanics characteristics of this new HCB material which was compressed partly before, combined with a large number of experimental study and theoretical analysis. The main achievements are following:(1) Proposed the concept of HCB effective cushioning state. Named the peak stress as the compression starting point, and divided the cushioning process of HCB after compressed into two stages, elastic absorbing and plastic absorbing, the effective cushioning was the state that energy could be absorbed well and deformation could be controlled. Furthermore, the range of effective cushioning state increased with the compression ratio together.(2) Set up the mechanics model of HCB under pre-compression, and pointed out that this new material was still viscoelastic-plastic. the core layer contains plastic hinge and the original upright part, the shape of honeycomb core is almost same as before, the cellular hole wall thickness of plastic hinge part is about equal to the half of the length of a side, and the mechanical model included elastic, yield and plastic part, in elastic stage, Yang's modulus is significantly reduced and is about the three function to the pre-compression ratio, but the mechanical model in yield and plastic deformation stage is the same as original.(3) Got the C -σm curve through the static compression test to pre-compression HCB, study its static cushioning performance. The results show that, the D-value between actual and theory thickness of pre-compression HCB is equal to peak point deformation, material has some recovery ability; Bearing capacity of the material increased significantly, but the pre-compression ratio has little effect; Cushioning efficiency increased as follow as the pre-compression ratio, and structure parameters also have influence on the cushion performance more or less.(4) Got the G ?σst curve through the impact test to pre-compression HCB, research its dynamic cushioning properties. The results are as followed, when drop height is certain, Gm increased gradually as the pre-compression ratio, and the impact resistance of the material decreased.(5) Research the creep properties of pre-compression HCB through creep test. The points are those, as follow as the pre-compression ratio increased, the creep deformation of material increased gradually, and the time of creep initial phase was shorter, creep resistance of the material got worse.
Keywords/Search Tags:Honeycomb paperboard, effective cushioning, Pre-compress, Cushioning performance, Creep, Mechanical model, Constitutive equation
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