香梨与瓦楞纸板跌落碰撞的接触应力分布分析及损伤预测

Contact Stress of Drop Impact to Corrugated Board and Damage Predication for Korla Pear

为了实现香梨果实跌落碰撞时损伤面积的准确评估和预测,本研究采用Prescale感压胶片对香梨与瓦楞纸板不同高度跌落碰撞下的接触应力分布进行测量分析,探讨接触应力分布与损伤面积的关系,确定了最接近损伤面积的应力面积范围。并在此基础上采用有限元模拟方法对香梨碰撞瓦楞纸板的损伤面积进行预测分析。研究结果表明,感压胶片测量的接触应力分布中>0.20 MPa范围的应力面积与损伤面积最为接近,相对误差率平均为6.81%。当该应力范围应用于有限元模拟的损伤面积预测时,香梨损伤面积的预测值略高于实际损伤面积,损伤预测的相对误差率平均约为13.29%,显著提高了预测精度,实现了有限元法对香梨与瓦楞纸板跌落碰撞损伤面积的较准确地预测,为今后香梨机械化作业中减损设计提供了研究基础。

In order to predict damage area of Korla pear after drop impact accurately, the contact stress characteristics for Korla pear impacts against corrugated board at varied drop heights were measured using pressure-sensitive film. Meanwhile, the relationship between the area occupied by the pressure and damage area was investigated and the range of stress area that closed to the damage area was determined. Furthermore, the finite element analysis （FEA） was used to predicate the damage area for Korla pear impact. The film measurements showed that the stress area more than 0.20 MPa was well approximate to the damage area, and the relative error rate was around 6.81%. When the above-mentioned contact stress range was applied to pear model of FEA for estimation of damage area, the predict value was slightly higher than actual one and the relative error rate was around 13.29%. Therefore, the results can provide data for damage predication of Korla pear packaged in corrugated board and ,the design of packing tools thereby reducing the damage occurring.