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

Aiming at the problem that it is difficult to directly obtain the threedimensional resistance variation law and soil dynamic behavior characteristics of the soil contact componentneedle body through experiments when the liquid fertilizer hole applicator is pricked with the inclined pricking hole mechanism. By adopting the Drucker-Prager yield criterion to construct the finite element model of hole application soil, the ADAMS kinematics analysis module was applied to obtain the pricking hole track of fertilizer spraying needle of pricking hole mechanism, and ANSYS/LS-DYNA display dynamics software was used to establish the interaction simulation model between fertilizer spraying needle and soil. Taking the maximum pressure on the needle body in the Zaxis direction as the measurement index and the working parameters as the influencing factors, the virtual and bench comparative tests of single way stress on the fertilizer spraying needle were carried out. The results revealed that the pressure was increased first and then decreased with the increase of the advancing speed and the rotation of puncture speed. The simulation and test data were close in size and the change trend was basically the same. Taking the advance speed of the fertilizer spraying needle (062m/s), the rotation speed of the puncture hole (70r/min) and the inclined angle (20°) as the simulation working parameters, the threedimensional resistance of the needle body and the dynamic behavior of the soil were simulated and analyzed. The analysis disclosed that the resistance of the fertilizer spraying needle in the three directions was increased first and then decreased. Within 0~0189s, the process of the fertilizer spraying needle entering the soil, the resistance of the needle body was changed slowly in the Xaxis direction, indicating that the fertilizer spraying disturbed less to the soil in the advancing direction. The resistance of the needle body was increased rapidly in the Zaxis direction, which indicated that the fertilizer spraying needle had a strong impact on the soil. The stress of the soil was mainly concentrated in this direction due to the shear of the needle tip, and the resistance reached the maximum value of 21.69N at 0.189s. The resistance of the needle body in the Yaxis direction was small, which indicated that the squeezing effect of the fertilizer spraying needle on the soil was weak, and the resistance reached the maximum value of 8.56N at 0.189s. Within 0.189~0.214s, the original position of the fertilizer spraying needle swung itself, the resistance of the needle body was increased rapidly in the Xaxis direction, which indicated that fertilizer spraying needle triggered great disturbance to the soil in the advancing direction. The resistance values in the other two directions remained basically unchanged. Within 0.214~0.350s, the excavation of the fertilizer spraying needle, the resistance of the needle in the Zaxis and Yaxis directions were gradually decreased until it became zero. Among them, within 0.214~0.238s, the resistance of the needle body in the Xaxis direction was increased instantly, indicating that fertilizer spraying produced strong extrusion on the soil in the forward direction, reaching the maximum value of 31.87N at 0.238s. During the whole pricking process, the formation of the puncture opening was mainly caused by the swing posture of the fertilizer spraying needle itself and the soil disturbance in the forward direction during the excavation process. Therefore, the resistance of the needle body along the Xaxis direction was influenced significantly, which conformed to the actual pricking hole law. The simulation method of needlesoil interaction provided can be a reference for the optimization design of fertilizer spraying needle and the research of clay characteristics.