香梨跌落碰撞接触应力分布特性及损伤估测

Measurement of contact pressure distribution and bruise estimation for drop impact of Korla pear

针对香梨跌落碰撞损伤问题，采用感压胶片测量技术分析香梨与4种接触材料在不同高度跌落碰撞的接触应力分布特性。结果表明，香梨与钢板及缓冲性能较低的橡胶板、HDPE板跌落碰撞时，不同范围应力呈正态分布，0．2～0．4MPa范围的应力面积最大，采用总应力面积能够较准确估测损伤面积，相对误差分别为4．84％，1．83％，3．21％；与瓦楞纸板跌落碰撞时，≤0．2MPa范围应力面积较大，采用〉0．2MPa范围的应力面积能够较准确估测损伤面积，相对误差为6．81％。该研究结果对实践中香梨损伤面积的估测和机械作业中减损设计的接触应力有限元模拟分析提供了依据。

Aiming to impact damage of Korla pear, the contact pres sure characteristics of Korla pear drops against four counterfaces at varied drop heights were analyzed using pressure-sensitive film. The results showed that the pressures tended to a normal distribution and the 0.2 ~ 0.4 MPa pressure covered largest area when Korla pears impacted against steel, rubber and HDPE board. The total pressure area could relatively accurate to estimate bruise area of Korla pear. The relative error rates for bruising estimation of pear dropped on steel, rubber and HDPE board were 4.84%, 1. 83% and 3. 21%, respectively. For Korla pears impacted against corrugated board, it was founded that the pressure below 0.2 MPa in larger area. Also, the area occupied by the pressure greater than 0.2 MPa was well es timated the bruising area with low relative error rate of 6.81%. The results provided a useful reference for bruise area estimation of Korla pear and estimate stresses using finite element analysis of the Korlajourney.