A model of elastic impact (EI) and a model that considers energy dissipation (CED model) were developed to describe the deformation behavior during litchi impact. In the CED model, dissipation energy is due to damping effect and the change of elastic modulus after impact. Drop tests of fruit onto a fixed plate were conducted with a pendulum device for three litchi cultivars (‘Nuomci’, ‘Guiwei’, and ‘Lvhebao’) to test the accuracy of the two models. The results show that the CED model better simulated the change of fruit velocity during impact and better predicted the occurrence time of maximum impact force and maximum deformation compared to the EI model. Both models accurately predicted the maximum impact force of ‘Guiwei’ litchi with all errors less than 5 %, but had errors up to 24.8 % for the prediction of the maximum impact force of ‘Nuomici’ and ‘Lvhebao’ litchis at high drop heights (drop height ≥ 400 mm). The CED model accurately predicted maximum deformation (errors less than 8 %) but the EI model over-predicted maximum deformation with errors range from 12.2 % to 39.2 % at all drop heights for the three tested cultivars. Both models predicted the contact time with low-level errors (<10 %). With a reliable theoretical model, the impact characteristics of litchis can be calculated and then applied to assess the fruit damage degree.

开发了弹性冲击模型（EI）和考虑能量耗散的模型（CED模型）来描述荔枝冲击过程中的变形行为。在CED模型中，耗散能量是由于阻尼效应和冲击后弹性模量的变化所致。使用摆锤装置对三个荔枝品种（'诺姆奇'，'桂微'和'绿河堡'）的摆锤进行水果落到固定板上的测试，以测试两个模型的准确性。结果表明，与EI模型相比，CED模型能更好地模拟水果在撞击过程中的速度变化，并更好地预测最大撞击力和最大变形的发生时间。两种模型均能准确预测'桂尾'荔枝的最大冲击力，且所有误差均小于5％，但误差不超过24。对于高落差（跌落高度≥400 mm），'Nuomici'和'Lvhebao'荔枝的最大冲击力的预测值为8％。CED模型可以准确预测最大变形（误差小于8％），但EI模型高估了三个测试品种在所有跌落高度下最大变形的误差范围为12.2％至39.2％。两种模型均以较低的误差（<10％）预测了接触时间。利用可靠的理论模型，可以计算出荔枝的冲击特性，然后将其用于评估果实受损程度。两种模型均以较低的误差（<10％）预测了接触时间。利用可靠的理论模型，可以计算出荔枝的冲击特性，然后将其用于评估果实受损程度。两种模型均以较低的误差（<10％）预测了接触时间。利用可靠的理论模型，可以计算出荔枝的冲击特性，然后将其用于评估果实受损程度。