针对经典Burger’s模型在蠕变特性表达中的不足，进行了绿熟期、变色期、红熟前期和红熟中期番茄果实的蠕变试验，并在Burger’s模型和常用指数型与幂函数型修正模型分析的基础上构造提出了4元件6参数修正模型。该模型对不同成熟期蠕变段试验数据拟合的平均决定系数与和方差分别达0.9975～0.9994和0.04047～0.07633，蠕变变形率和弹性度的拟合平均相对误差分别为2.54%～3.04%和2.89%～7.12%，蠕变量预测的平均相对误差为0.29%～0.46%，蠕变速率也与实际更加吻合，其曲线拟合精度、关键指标表达精度和蠕变预测精度大大优于Burger’s模型和常用修正模型。研究表明该模型实现了蠕变行为的更准确表征与预测，从而为果实收获、储运、分选的减损提供了更好的模型依据。%In this paper, creep deformation and recovery tests were processed for tomato fruits first with a TA-XT2i texture analyzer by randomly selecting every ten tomato fruits for a different ripening period. It was found the classical Burger’s model failed to express the strain saturation at the later creep objectively due to the constant Newtonian viscosity of the free dashpot, but the existing modified exponential and power-law models have also have the major defect that the viscosity of free dashpot at the later creep and initial deformation rate tend to infinity, respectively. So a new model that consisted of four elements with six parameters modified was proposed, by changing the constant Newtonian viscosity of a free dashpot to a power-law variable with a constant term in the viscous deformation term of the creep equation of Burger’s model. And then the curve fitting and prediction results of the new model were compared with those of Burger’s model and the existing modified exponential and power-law models. The average determination coefficient and the sum of squares due to the regression error of different ripening periods with the new model were 0.9975-0.9994 and 0.04047-0.07633, respectively, which are more ideal, obviously. The average relative errors of the rate of creep deformation, and the rate of elasticity with the new model were only 2.54%-3.04% and 2.89%-7.12%, respectively. The average relative error of the creep deformation prediction with the new model were 0.29%-0.46%, which are several times less than not only the Burger’s model but also the existing modified exponential and power-law models. Finally, the initial creep deformation rate of the new model was also closer to the real rate than any other models. To conclude, this study used a good 4-element with 6-parameter modified model to express and predict the creep behavior more accurately, which gives a better model option to bruise reducing in fruit harvesting, transporting or sorting.
展开▼
