A quantitative analysis method for contact force of mechanism with a clearance joint based on entropy weight and its application in a six-bar mechanism

Abstract

Contact force in a clearance joint affects the dynamic characteristics and leads to nonlinear response of the mechanism. It is necessary to assess the nonlinearity of contact force quantitatively. Therefore, a new method named contact-force entropy weight is proposed in this paper. This method presents a comprehensive description of the judgment matrix in the X, Y, and Z directions. To assess the influence degrees of different clearances and angular velocities on the contact force, the method is applied to numerical calculation and simulation of a six-bar mechanism with a clearance joint to illustrate its application and investigate the influence degree of angular velocity and clearance on the contact force. By combining the simulation results and theoretical calculations, the influence degrees of different clearances and angular velocities on the contact-force entropy weight of the six-bar mechanism with a clearance joint are revealed. It is found that the angular velocity has a significant influence on the contact force entropy weight of the clearance joint, showing that the contact-force entropy weight is a feasible new method of assessing non-linearity of contact force quantitatively. The method gives a theoretical reference for quantitatively analyzing the nonlinear dynamics.

Establishment and application of the environment evaluation model for beneficiation plant

“…In order to calculate the comprehensive weight, this project adopts the distance function, which can represent the difference between the entropy weight method and the the G1 method, The comprehensive empowerment can eliminate differences [18] . For the j-th index, ω * j, stand for the weight calculated by the G1 method while ωj, stand for the weight calculated by the entropy weight method, the steps are shown as follows.…”

Analysis and Optimization of Mud Pump Crankshaft Structure based on Nonlinear Regression Model

“…The difference between the three optimization schemes is not obvious from Table 5, so the multi-objective optimization method is needed to further investigate the optimization problem and find the optimal solution after weighing the three optimization objectives of total crankshaft mass, maximum deformation, and maximum stress. The entropy weight method [7] was used to explore the three optimization objectives and the objective weights of the optimization objectives were obtained as shown in Table 6, so after the multi-objective optimization method was carried out, the comparison of the three optimization objectives before and after optimization was worth as shown in Table 7. From Table 7, it can be seen that the maximum deformation of the crankshaft, the total mass and the maximum stresses sustained after optimization are reduced, and the maximum deformation of the crankshaft is still within the strength tolerance range, so this optimized structure can be accepted.…”