Jinjie Wang

Lateral response of cable-guided hoisting system with time-varying length: Theoretical model and dynamics simulation verification

The lateral response of the moving hoisting conveyance in cable-guided hoisting system is investigated in this paper. The equations of motion are derived by Hamiltons principle while the equivalent mass and stiffness of the guide cables are formulated. Galerkin method is employed to transform the governing equation into a set of ordinary differential equations. Subsequently, an ADAMS simulation model based on multi-degree of freedom is established to validate the theoretical model. Meanwhile, a high-efficiency simulation approach is proposed, in which the contact force is replaced with fixed joints and distance sensors. The numerical solution for equations set is obtained using Newmark-β method and the convergence of the solution is discussed, then the presented theoretical model is compared with the previous models describing the rigid rail-guided hoisting system. The results indicate that the numerical simulations are in reasonably good agreement with the ADAMS simulations and this presented model includes the previous models. The influence of parameters on the lateral response is analyzed, which reveals the maximum lateral displacement is linearly proportional to the excitation amplitude. Also, the appropriate preload can be determined by the theoretical model, which is beneficial for vibration control.

A NOVEL DRIVING STRATEGY FOR DYNAMIC SIMULATION OF HOISTING ROPE WITH TIME-VARYING LENGTH

A simulation method for investigating the vibration behavior of hoisting rope with time-varying length is improved. By previously creating markers in the MSC.ADAMS software package, the parametric model of the rope wound along helix is established based on the concentrated-mass theory with multi-degree of freedom (multi-DOF). A novel driving strategy, cooperating fixed joints with angle sensors under the control of driving script, is proposed to substitute conventional contact force. Researching on the hoisting rope in the sinking winch mechanism, an equivalent discretization model is obtained with complicated boundary conditions considered. The differential equations of motion of the hoisting system are formulated employing Lagranges equation and numerically solved using Runge–Kutta method. The simulation indicates that the horizontal swing is decreased in principle and the simulation with 800 discrete ropes is not performed more than 61 min. Therefore, this feasible strategy could not only guarantee the accuracy but also promote simulation efficiency and stability. The motion curves exported from ADAMS simulation coincide with one in numerical simulation, which validates both the numerical model and the driving strategy.

Coupled vibrations of rope-guided hoisting system with tension difference between two guiding ropes

The flexibility of the guiding rope and the tension difference between two guiding ropes cause the lateral and torsional vibrations of the hoisting conveyance in the rope-guided hoisting system, respectively, which are theoretically investigated with two different cases in this paper. The assumed modes method is used to discretize the hoisting rope and two guiding ropes, and Lagrange equations of the first kind is adopted to derive the equations of motion, while the geometric matching conditions at the interfaces of the ropes are accounted for by the Lagrangian multiplier. Considering all the geometric matching conditions are approximately linear, the differential algebraic equations are transformed to a system of ordinary differential equations. The current method can obtain not only the accurate lateral displacements of two guiding ropes, but also the constraint forces between the hoisting conveyance and two guiding ropes. Further, the current method is verified by the ADAMS simulation. Finally, the effects of various parameters on the lateral and torsional vibrations of the hoisting conveyance are analyzed and results indicate that the appropriate tension difference and distance difference could decrease the maximum lateral displacement, which is useful to design super deep rope-guided hoisting system for the decrease of the vibration.