Dropping impact mechanical characteristics of apple

In the process of sorting, packaging and transportation, the produce is submitted to impact which cause it's bruising. A testing system was developed to determine the mechanical parameters of produce during dropping impact. Two dropping impact tests were conducted on fresh 'Fuji' apples grown in Shandong, China. The one was dropping test at five heights of 15, 30, 45, 60, 75 cm. Another one was repeated impact test of the same point of the objects' surface at the same height. Based on the data of impact force versus time obtained from tests, the curves for acceleration versus time, deformation versus time, impact force versus deformation, stress versus strain and coefficients of restitution were obtained by theoretical analysis. Results show that with the increase of dropping height and repeated impact, the impact force, peak acceleration, maximum deformation and remaining deformation of apple increase. The impact resilience coefficients of restitution of apple reduce with the increase of dropping height, but increase with the increase of repeated impact. The influence of repeated impact on deformation of apple is not notable.