Abstract:Lotus seeds with different maturity have different mechanical properties. At present,shelling machinery is only suitable for lotus seeds after ripening stage. However,the crushing rate increases greatly when milk and wax ripening stages of lotus seeds are shelled. In order to improve the applicability of shelling machinery and reduce the crushing rate of fresh lotus seeds in the process of shelling and peeling,the compression,crushing and shearing characteristics of lotus seeds with different maturity were studied. In this study,the lotus seeds of space lotus No. 36 from Honghu Lake,Hubei Province were used to measure the shape dimensions and water content. The long-axis and short-axis compression and the crush test for whole lotus seed were conducted. The shear test under different speeds and depths,and the compression test in three-axis direction were carried out. The elastic modulus of lotus shell was tested. The long axis and short axis elastic modulus were analyzed and calculated based on experiments above. The ultimate failure load,the relationship between shear stress and depth,speed and maturity were obtained. The results showed that the average longitudinal and transverse ratio of the lotus seeds with milk maturity,wax maturity and maturity was 1.35,1.28,1.19,respectively. The water content was 79.84%,70.28%,57.72%,respectively. The long axis elastic moduli of lotus seeds were 1.09 MPa,1.22 MPa,and 1.85 MPa,respectively. The short axis elastic moduli were 1.33 MPa,1.42 MPa,and 2.16 MPa,respectively. The limit damage load of three maturity lotus seeds was 81.995 N,117.107 N,and 167.640 N,respectively. Under the same maturity and shear depth,the shear force did not change with shear speed and was linearly correlated with shear depth. The compression shelling force of lotus seed in the X,Y and Z directions increases with maturity. The compressive force in the three-axis direction of the lotus seed is numerically X axis