摘要
建立了葡萄的非线性力学模型。把葡萄简化成球形的、均匀的、各向同性的和内部充满不可压缩液体的弹性膜。研究了葡萄在压缩载荷作用下的应力分布和变形。利用膜理论建立了接触区域与非接触区域的平衡方程,确定了边界条件与连续条件。利用R unge-K u tta方法,进行数值求解,得到了在压缩载荷作用下葡萄的张力。结果表明:在压缩载荷作用下,葡萄纬线方向的张力大于经线方向的张力,最大拉力发生在赤道平面上,葡萄在压缩载荷作用下的损伤主要是由最大拉应力造成的,该结论与试验观察的结果相一致。
A nonlinear mechanical model of grape was constructed. The grape was assumed as a spherical homogeneous,isotropic elastic membrane, which was fully-filled with incompressible, high viscous liquid. The stress distribution and deformation of grape under compression load by two rigid plates were studied. The equilibrium equations for contacted regions and non-contacted regions were obtained by using the theories of membrane. The boundary conditions and continuity conditions for the solution of the differential equations were determined. The tension of grape skin under compression load was analyzed numerically, using Runge-Kutta iteration method. The results indicate that the stress in circumference is greater than that in the meridian direction. The failure of grape under compressive load was mainly caused by the maximal stretch stress which occurred at the equator. The results are consistent with the previous experimental observations.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2006年第10期26-30,共5页
Transactions of the Chinese Society of Agricultural Engineering
基金
The research was supported by the National Natural Science Foundation of China(10472132)
关键词
葡萄
机械损伤
压缩载荷
膜
拉应力
grape
mechanical damage
compression load
membrane
stretch stress
