ass日本风韵熟妇pics男人扒开女人屁屁桶到爽|扒开胸露出奶头亲吻视频|邻居少妇的诱惑|人人妻在线播放|日日摸夜夜摸狠狠摸婷婷|制服 丝袜 人妻|激情熟妇中文字幕|看黄色欧美特一级|日本av人妻系列|高潮对白av,丰满岳妇乱熟妇之荡,日本丰满熟妇乱又伦,日韩欧美一区二区三区在线

In order to improve the accuracy and reliability of using the discrete element method to guide the design and optimization of banana straw crushing and returning equipment, Hertz-Mindlin with bonding contact model was used to establish the discrete element bonding model of banana straw and carry out parameter calibration. The impact recovery test, static friction test, and rolling friction test were carried out by high-speed photography technology, and the basic discrete element model contact parameters such as impact recovery coefficient, static friction factor, and rolling friction factor of banana straw were determined. Physical and simulated shear tests of banana straw were carried out to obtain the mechanical characteristic curve of destroying banana straw outer skin, and the maximum physical shear force was determined to be 122.41N. The optimal parameter combinations of normal contact stiffness, tangential contact stiffness, critical normal stress, and critical tangential stress of the banana straw bonding model were determined by central composite design (CCD) response surface method. The simulation results showed that the relative error between the simulated shear force results and the physical shear force was only 2.34%, which verified the reliability and accuracy of the bond parameter calibration method, and provided a theoretical reference for the design and research of the banana straw crushing and return machine.