咀嚼运动对食品物料破坏效果的仿真分析

Simulation Analysis of Food Materials Damage Effect Based on Chewing Movement

摘要:

采用逆向工程技术重构了切牙和在咀嚼运动中起主要作用的上、下第一磨牙的三维模型，结合现代牙合理论与颞下颌关节运动理论构建了咀嚼运动的简化模型，将咀嚼运动分为三种模式：切割模式、杵压模式、研磨模式，仿真了咀嚼破碎食品的过程；基于食品物料的弹塑性本构模型，引入联合强度理论，分析了咀嚼运动规律对食品物料破坏程度的影响。匀速运动模式取5个不同的速率，结果表明在研磨模式下，较高的咀嚼速率对食物的破坏效果较好，其中咀嚼0.3 s时产生的剪切应力和密赛斯应力最大，分别为16.07 MPa和14.20 MPa；变速运动模式的仿真时间均取0.2 s，结果表明加速度变化对咀嚼效果的影响相对较弱，其中，匀加减运动能产生较大的剪切应力和密赛斯应力，分别为15.64 MPa和13.86 MPa，其更适合于研磨弹性和韧性食品。

Abstract:

Reverse engineering technology was used to reconstruct three-dimensional models of the incisors as well as top and bottom first molars which played a major role in the chewing movement. The simplified chewing movement models were constructed by modern occlusion theory and temporomandibular articulation movement theory, and it was divided into three modes: cutting mode, compressing mode and grinding mode, which simulated the whole process of chewing and crushing food. Based on the elastic-plastic constitutive model of food materials, the joint strength theory was introduced to analyze the effect of chewing movement rule on the degree of material damage. Five different rates were taken by uniform motion mode, and the results showed that under the grinding mode, the higher rate of chewing had good effect on the destruction of the food. And the greatest shear stress and mises stress were achieved after chewing for 0.3 s, being of 16.07 MPa and 14.20 MPa respectively. When the simulation time of variable motion model was 0.2 s, the effect of chewing acceleration was relatively weak. Therefore, the larger shear stress and mises stress were produced by uniform variable motion, which were 15.64 MPa and 13.86 MPa, respetively. So it was more suitable for grinding flexible and durable food.