摘要
目的 为解决缓冲材料发泡聚乙烯因蠕变引起保护失效的问题,基于Burgers模型,分析载荷、应力保持时间对EPE压缩蠕变行为的影响。方法 根据不同应力下的不同保持时长压缩蠕变试验结果,拟合EPE不同应力下的压缩蠕变试验数据,分析不同应力、应力保持时间下的EPE蠕变过程中蠕变总量、弹性应变、黏弹性应变和黏性应变的变化规律。结果 Burgers四元件力学模型对EPE不同应力下的压缩蠕变实验数据拟合度为0.992 4~0.998 9。在同一应力保持时间下,随着应力从3.3 kPa增加到5.3 kPa,弹性模量E_(1)、弹性模量E_(2)、黏度系数η_(2)、黏度系数η_(1)都逐渐减小,蠕变总量、黏性应变呈非线性显著增加,弹性应变、粘弹性应变呈线性微量增加;在同一应力下,随着应力保持时间从20 d增加到120 d,弹性应变一直保持不变,占蠕变总量的比例降低,粘弹性应变先微量增加后保持不变,占蠕变总量的比例降低,黏性应变增加,占蠕变总量的比例增加。结论 Burgers模型可较准确地模拟EPE不稳定蠕变阶段和稳定蠕变阶段的压缩蠕变行为;应力的增加导致EPE抵抗变形的能力变弱,引起蠕变量增加;应力保持时间的增加对弹性应变无影响,对稳定蠕变阶段的黏弹性应变无影响,对黏性应变的增加有显著影响。
In order to solve the problem of protection failure caused by creep of cushioning material foamed polyethylene, the effects of load and stress holding time on the compressive creep behavior of EPE cushioning material were analyzed based on Burgers model. Based on the results of the compression creep test results of different holding time under different stresses, the compression creep test data of EPE under different stresses were fitted to analyze the changes of creep total, elastic strain, viscoelastic strain and viscous strain during the creep process of EPE under different stresses and stress holding time. The experimental data fit of Burgers four-element mechanical model for compression creep of EPE under different stresses ranged from 0.992 4 to 0.998 9. At the same stress holding time, as the stress increased from 3.3 kPa to 5.3 kPa, the elastic modulus E_(1), elastic modulus E_(2), viscosity coefficient η_(2) and viscosity coefficient η_(1) all decrease. The total creep and viscous strain increase nonlinearly, while the elastic strain and viscoelastic strain increase linearly. At the same stress, as the stress retention time increases from 20 days to 120 days, the elastic strain remains constant and its proportion to the total creep decreases. The viscoelastic strain increases slightly at first and then remains constant, and its proportion to the total creep decreases while the viscous strain increases and its proportion to the total creep increases. Burgers model can accurately simulate the compressive creep behavior of EPE in unstable creep stage and stable creep stage. The increase of stress leads to the weakening of EPE’s ability to resist deformation and the increase of creep. The increase of stress holding time has no effect on the elastic strain, and has no effect on the viscoelastic strain in the stable creep stage, but has a significant effect on the increase of viscous strain.
作者
刘艳华
黄利强
付志强
何争辉
张武杰
刘昊喆
LIU Yan-hua;HUANG Li-qiang;FU Zhi-qiang;HE Zheng-hui;ZHANG Wu-jie;LIU Hao-zhe(School of Light Industry Science and Engineering,Tianjin University of Science&Technology,Tianjin 300222,China;Laboratory for Innovative Design of Package,Tianjin University of Science&Technology,Tianjin 300222,China)
出处
《包装工程》
CAS
北大核心
2022年第7期146-153,共8页
Packaging Engineering
基金
天津市教委科研计划(自然科学)(2019KJ209)。
