Introduction and analysis of Adams kinematics of t

2022-07-30
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The Adams of the container front crane directly discards the s kinematics analysis

1 Adams model

the container front crane is mainly composed of jib, frame body, front and rear tires, pitching hydraulic cylinder, telescopic hydraulic cylinder, cab, oil tank, steering system, hydraulic system, transmission system and lifting appliance. Its Adams geometric model is shown in Figure 1

among them, the coordinate system takes the midpoint of the connecting line between the two hinge points of the boom production, marketing, research and application combined with the push replacement inlet frame and the frame as the coordinate origin, the horizontal extension direction of the boom is the positive direction of the X axis, and the vertical direction is the positive direction of the Y axis. Among them, consider the most unfavorable situation that the mass center of the lifting weight (container) is offset by 0.8 m in the z-axis direction

create constraint pair according to the connection relationship of each component with the environment, create a cylindrical pair between the cylinder block and the piston rod of the front and rear pitching hydraulic cylinders; Considering that the two pitching hydraulic cylinders are subject to different forces when the weight is lifted off track, create bushings between the pitching hydraulic cylinder and the piston rod and the basic arm, and between the basic arm and the frame body respectively; In addition, a translation pair is created between the basic arm and the telescopic arm to represent the movement of the telescopic hydraulic cylinder; Create a rotating pair at the lifting point of the telescopic boom and the lifting weight

Figure 1 Adams motion analysis model of container front crane

create sensor definition sensor 1 detects the stroke of pitching hydraulic cylinder, with a range of 0~2.78 m; Sensor 2 detects the stroke of telescopic hydraulic cylinder, with a range of 0~7.07 m; Sensor 3 detects the boom tilt angle, with a range of 0~59.26 °

to define the motion, first create a vertical upward linear motion 1 at the lifting point to meet the requirements of lifting speed of 0.25 m/s. The motion curves of the pitching hydraulic cylinder and the telescopic hydraulic cylinder are obtained through the motion pair. Based on this curve, the cubic spline motion curves 1 and 2 of the pitching hydraulic cylinder and the telescopic hydraulic cylinder are inversely obtained. The motions 2 and 3 of applying two pitching hydraulic cylinders are cubic spline motion curve 1, and the motion 4 of telescopic hydraulic cylinder is cubic spline motion curve 2. Finally, delete linear motion 1

2 analysis conditions

four different lifting load conditions at four different positions in three rows are considered, as shown in Figure 2

Figure 2 container front crane position and load conditions

the position, lifting load and parameters of telescopic hydraulic cylinder under various working conditions are shown in Table 1. Working condition data sheet of front crane

position rated lifting mass (T) x coordinate of lifting load boom inclination angle (°) 1458.582552 432546.. 932531.734438.582559.26

3 Adams analysis results and comparative analysis with finite element results

3.1 Adams analysis results

carry out Adams kinematics simulation for the above four different working conditions, and obtain the displacement, speed, acceleration and stress curves of the two pitching hydraulic cylinders and telescopic hydraulic cylinders with time, as well as the curve of the binding force at the hinge point of the basic arm and the frame body with time. The graph shows the simulation curve of the process of lifting a 45t container to position 1

3.2 comparison and analysis with finite element results

when lifting to four position points, the AMS analysis results of the forces on the hinge points of the basic arm and the frame body, the pitching hydraulic cylinder and the telescopic hydraulic cylinder and the comparison and analysis with the results of the strand finite element calculation are shown in Table 2

4 conclusion

(1) using ADAMS kinematics analysis, we can get the parameter curve of the container front crane in the whole movement process, including displacement, velocity, acceleration, force and so on

(2) NASTRAN is used to calculate the finite element under various typical working conditions when a load is hoisted to a certain position, and the results are compared with the ADAMS simulation results. The relative error is between 0.19%-8.88%, which can verify the correctness of the ADAMS simulation results

(3) it can provide a theoretical basis for the design of container front crane, especially the design of pitching hydraulic cylinder, telescopic hydraulic cylinder and boom. (end)

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