论文部分内容阅读
假定水稻为复合椭球体 ,在圆柱坐标下 ,利用有限元法 ,通过改进的传质模型和粘弹性力学模型 ,对吸湿环境下水稻颗粒内部水分分布和应力应变分布进行数学模拟。模拟结果表明 :水稻吸湿时 ,表层含水率很快达到平衡水分 ,中心含水率变化缓慢 ;水稻颗粒中心所受拉应力最大 ,表层所受压应力最大 ,沿颗粒横向从内向外应力由受拉逐渐变为受压 ;水稻颗粒中心首先形成应力裂纹的可能性最大。利用吸湿实验对模拟结果进行了间接验证。
Assuming that rice is a complex ellipsoid, the mathematical model of water distribution and stress-strain distribution in rice grains under hygroscopic environment is simulated by cylindrical finite element method with improved mass transfer model and viscoelastic model. The simulation results show that the surface water content reaches the equilibrium moisture quickly and the center moisture content changes slowly when the rice absorbs moisture. The rice grain center suffers the largest tensile stress, the surface layer receives the largest compressive stress, and the grain stress gradually increases from the inside to the outside Become pressure; rice grain center is the most likely to form stress cracks. The moisture absorption experiment was used to verify the simulation results indirectly.