Experimental study on mechanical properties of litchi branches

In order to obtain the mechanical characteristic parameters of litchi branches, using “Nuomici” branches as experimental material, compressing test and shear test were conducted in the accurate Micro-controlled electronic universal testing machine. The results showed that average value of crushing strength parallel to the grain was 32.77 MPa, modulus of elasticity parallel to the grain 1068.02 MPa and mean value of the compression energy parallel to the grain 56.57 N·m. Average value of the compressive proportional limit stress perpendicular to grain was 8.02 MPa, modulus of elasticity perpendicular to grain was 422.84 MPa and mean value of the compression energy perpendicular to the grain was 1.25 N·m. Average value of the shear strength was 9.52 MPa and shear power was 17.59 N·m. The relevant changing trends of mechanical characteristic parameters of branches were analyzed with statistical software. The results also showed that there was an exponential function positive correlation between the stress resistance intensity and compression energy parallel to the grain, weak logarithmic function positive correlation between the compressive proportional limit stress and compression energy perpendicular to the grain, and significantly positive linear correlation between maximum shear force as well as shear power and the cross-sectional area. These results provide foundational parameters to develop pruning machine.