卢立新. 跌落冲击下果实动态力学模型[J]. 工程力学, 2009, 26(4): 228-233.
引用本文: 卢立新. 跌落冲击下果实动态力学模型[J]. 工程力学, 2009, 26(4): 228-233.
LU Li-xin. NON-LINEAR VISCOELASTIC MODELING OF THE FRUITS UNDER DROPPING IMPACT[J]. Engineering Mechanics, 2009, 26(4): 228-233.
Citation: LU Li-xin. NON-LINEAR VISCOELASTIC MODELING OF THE FRUITS UNDER DROPPING IMPACT[J]. Engineering Mechanics, 2009, 26(4): 228-233.

跌落冲击下果实动态力学模型

NON-LINEAR VISCOELASTIC MODELING OF THE FRUITS UNDER DROPPING IMPACT

  • 摘要: 基于果实跌落冲击动力学特征,提出一表征其冲击条件下的非线性力学模型与模型参数识别方法。以红富士苹果为研究对象,进行多个高度下的跌落冲击试验,基于试验数据识别获得了不同高度下的模型弹性系数、粘性系数以及粘性特征参数。在此基础上,基于损伤因子方法,定义苹果跌落冲击损伤变量,并据此进行不同跌落高度下力学模型的统一表征,得到红富士苹果粘弹性损失系数。结果表明:与已有模型比较,该文提出的理论模型与试验结果吻合性最好;该理论模型与试验结果吻合度高,所提出模型能合理地表征苹果及类似特性果实的非线性粘弹性力学特征。研究结果为果实动态力学特性分析以及模型表征提供了一种新的方法,也为进一步表征果实的粘弹塑性损伤特征提供基础。

     

    Abstract: A dynamic non-linear viscoelastic model and its parameter-identification method are developed for the fruits under dropping impact. This model defines the force acting on the fruit as a summation of nonlinear elasticity force and viscous damping force . An experimental system is set up to measure and analyze the dropping impact on fruits. The dropping impact on fresh ‘Fuji’ apples was tested at multi-heights . The model parameters corresponding to different dropping heights are estimated based on the experimental data. Applying the method of bruise factor, the impact bruise variable is proposed, and the general viscoelastic bruise model is developed, thus, the bruising factor of apple dropping is estimated. The results show that the initial velocity of impact affects the model parameters significantly. Compared with other models, the proposed non-linear viscoelastic model is the most precise one in simulating the relation between the impact force and the deformation.

     

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