荔枝整果压缩力学特性试验

Experimental Research of Compression Mechanical Properties for Whole Litchi

为减少机械损伤,水果采摘机械的设计与控制需充分考虑水果整体力学特性。对荔枝整果进行压缩试验,分析研究荔枝在压缩载荷下的变形规律和重复加载时其刚度的变化,根据Hertz接触理论求得整体荔枝压缩时弹性模量与变形量的关系曲线,通过对试验曲线的拟合求得荔枝刚度与变形的二次关系式。试验范围内得到的荔枝果壳破裂力为30～40N,其受载时趋于稳定的刚度值为6.3954×103N/m。该研究为采摘机械的设计、减少采摘损伤控制最小的载荷提供了参考依据。

To reduce the mechanical damage for fruit,the whole mechanical properties were needed to be considered sufficiently when designing and controlling fruit picking machinery.Through compression experiences for litchi,its deformation law under load and stiffness change when re-load were analyzed.According to the Hertz contact theory,the relationship curve between elastic modulus and deformation when compressing has been obtained.Moreover,quadratic about litchi＇s stiffness and deformation can be obtained by fitting the experimental curve.The experience revealed that the rupture force of litchi shell reached 30-40 N,and its stiffness would tended to stabilize in 6.395 4×103 N/m.