Test and analysis of mechanical properties of poplar branches

The mechanical properties of poplar branches are the basis for designing and optimizing the working parameters of branch pruning and crushing machinery. In this paper, a precision microcomputer-controlled electronic universal testing machine was used to test the tensile, compression, bending, and shear mechanical properties of poplar branches. The test results suggested that the elastic constitutive relationship of the stress-strain curves of poplar branches under longitudinal compression, transverse compression, and bending conformed to Hooke's law, and longitudinal tensile and shear exhibited plastic damage; the anti-failure strength, anti-failure elastic modulus and external work of poplar branches under longitudinal compression were greater than those under transverse compression. Meanwhile, the analysis results indicated that there was an exponential function positive correlation between longitudinal tensile strength and longitudinal tensile work, a polynomial exponential function positive correlation between longitudinal compressive strength and longitudinal compressive work, a power function positive correlation between transverse compressive proportional ultimate strength and transverse compressive work, and an exponential function positive correlation between bending strength and bending work; meanwhile, there was a polynomial function positive correlation between the peak shear force and the cross-sectional area of the sample, and there was an exponential function positive correlation between the shear work and the cross-sectional area of the sample. Additionally, the external work required to destroy poplar branches can be estimated using the established regression equation. The study results of this paper provide important data support for poplar branch pruning and crushing simulation tests and machine power selection.