梨果实振动损伤及其对蠕变特性的影响

Effect of vibration on bruising and creep property of pear fruit

振动是导致果实运输直接机械损伤,并继而引起果实振动后的组织流变特性变化而易发生延迟损伤的主要因素之一。该文以梨果实为研究对象,首先进行振动扫频与多种工况下的模拟运输振动试验,研究其振动及其损伤特性。结果表明:梨果实的振动响应具有非线性特征,同时获得了梨果实振动损伤体积与振动时间的关系式。在此基础上,测定分析振动时间对梨果实蠕变特性的影响,提出了考虑振动时间影响的梨果实黏弹性蠕变模型,表征模型参数,分析振动时间对模型参数的影响。

Vibration is one of key factors to cause the directly mechanical bruising and the change of rheologic character of fruits during transport.The experiments of sweep vibration and simulated transport vibration under different conditions were conducted for pear fruit to analyze its vibration characters and vibration bruising.Results show that pear fruit behaves nonlinear vibration response under sweep vibration of varied acceleration excitation.The relationship of vibration bruising volume and vibration time of pear fruit was obtained.Then,the creep experiment of pear fruit was conducted after different vibration times.A viscoelastic model of creep corresponding to vibration time was proposed. Base on the data of creep experiments of pear fruit,the model parameters were obtained and the effect of vibration time on the model parameters was estimated.