基于松弛试验的蓖麻籽压榨非线性流变模型

A nonlinear rheological model of castor pressing based on stress-relaxation tests

摘要:
目的揭示蓖麻籽压榨过程中的流变特征.
方法利用单轴压榨试验装置进行应力松弛试验，获取了松弛过程中应力与时间关系.基于试验结果和半理论半经验法，利用改进的广义Maxwell模型建立了蓖麻籽压榨非线性流变模型，使用非线性回归法分段对模型参数进行求解，并将模型计算值与试验结果对比.
结果和结论 综合对比结果可知：模型模拟值与应力松弛试验结果吻合较好，该模型能较好的模拟压榨应变大于0.65时蓖麻籽的非线性流变特性.

Abstract:
Objective To reveal rheological characteristics in the process of castor seed press.
Method The stress-time relationship of stress-relaxation process was obtained by stress-relaxation tests with the uniaxial compression equipment. Based on the results and the semi-theoretical and semi-empirical method, a nonlinear rheological model was established using the improved generalized Maxwell model. The parameters of the model were achieved by nonlinear regression method.The calculated values of model were compared with the experimental results.
Result and conclusion The results show that the model calculated values matching well with the experimental results, which means the model can simulate nonlinear rheological properties of castor seeds when the strain is over 0.65.