Experimental Study on Physical and Mechanical Characteristics of Sweet Potato Root
Most of the mechanical equipment for sweet potato production is based on that for potato production,lacking theoretical design and analysis basis.In order to provide relevant theoretical parameters and analysis basis for the design and optimization of sweet potato harvesting,transportation,and sorting machinery,this study explores the physical and mechanical properties of mature sweet potato tubers in different directions and positions,to lay a foundation for the development of high-performance machinery.Taking the widely planted Yanshu 25 variety in Liaoning Province as the research object,the water content and density of mature tubers were obtained,and the basic physical parameters of the tested tubers were determined.The mechanical compression properties of the tubers in the axial,radial,and some other directions were tested using the INSTRON 5944 electronic universal testing machine,and the trend of the breaking force with the loading speed was obtained.The elastic modulus,Poisson's ratio,and shear modulus of the potato pieces in different compression directions and positions were analyzed,and the material properties of sweet potato were determined.The results show that the water content of mature Yanshu 25 sweet potato is 79.64%,and the density is 1 028 kg·m-3.The elastic modulus,Poisson's ratio,and shear modulus of potato pieces in different compression directions are not significantly different,indicating that sweet potato is an isotropic material.The elastic modulus,Poisson's ratio,and shear modulus of potato pieces in different positions are not significantly different,indicating that sweet potato is a homogeneous material.The elastic modulus of sweet potato is 3.22 to 4.19 MPa,the Poisson's ratio is 0.28 to 0.40,and the shear modulus is 1.26 to 1.50 MPa.The research findings may provide foundation for the design of mechanized equipment for sweet potato production and the establishment of subsequent simulation models.
sweet potatophysical and mechanical characteristicscompressive mechanical properties