Recent  

In the present paper, study on meshing stiffness characteristics of the modified variable hyperbolic circular-arc-tooth-trace cylindrical gears was proposed. The modified tooth surface equation was deduced, and a 3D model was developed. The load tooth contact analysis (LTCA) model was developed. The meshing stiffness calculation method  was proposed and verified by the finite-element calculation. The influence of the load and modification parameters on the stiffness was investigated.

Friction is widely present in moving mechanical systems, and it has a negative impact on the performance of mechanical systems, such as tracking errors during low-speed motion. To overcome the impact of friction on the control accuracy of the system, this paper proposes a dynamic continuous friction model based on numerous current friction models. Based on this friction model, the velocity control mode of the direct-drive system is compensated for, and good results have been achieved.

A new type of parallel six-dimensional force sensor was developed, and artificial neural network technology was used to achieve decoupling of the sensor output data. In addition, a gravity compensation method based on CAD variable geometry is proposed to optimize the performance of the six-dimensional force sensor.

The speed of vehicles has a significant impact on the safety and comfort of driving. When vehicle passes over different speed bumps, it becomes a practical research topic to choose the appropriate speed at which to pass over. In this paper, we establish a multi-objective optimisation method through vehicle dynamics feedback combined with an immune algorithm and then design and carry out the solution process of the vehicle multi-objective optimisation problem.

Using loop equations and branch graphs, we propose a method to construct single-degree-of-freedom (single-DOF) multi-mode-planar mechanisms (MMPMs), replacing links or components of the singular configuration of planar mechanisms with multi-mode modules. The method is straightforward, visible, and widely applicable to single-DOF MMPMs. We give new design direction and powerful design guidance for the design of MMPMs, along with the available configuration and more choice for the application.

The relationship between installation error and contact performance was studied. The tooth surface equation and contact ellipse were deduced, and the imprinting experiment was realized. The tooth contact analysis (TCA) model was developed to investigate the influence of the installation error on the contact area. The formulas of the gap and flexibility matrix were given to develop the loaded TCA (LTCA) model. The influence of the installation error on load distribution was investigated.

To evaluate the residual stress level in pipeline welding, a finite-element welding model was established, and the influence of welding parameters on the residual stress was analyzed. The ultrasonic LCR stress-detecting method was used to measure the actual residual stress. The comparison results indicate that the finite-element welding model is effective, through which the welding technical parameters can be optimized and the welding residual stress of pipeline can be reduced.

In this study, to conduct and gain a deeper understanding of the cutting mechanism of SiCp / Al in ultrasonic vibration-assisted turning, this study established a prediction model for the cutting temperature field of SiCp / Al composite materials in UVAC cutting. At the same time, experiments were conducted on processing SiCp / Al composite materials using UVAC, turning SiCp/Al composite materials with a volume fraction of 25 %.

A piezoelectric ceramic micro-feed tool holder relies on the piezoelectric ceramic inverse piezoelectric effect to achieve high-frequency precision micro-drive, leading to advantages such as a fast response time and high stiffness. In the present study, a new micro-feed tool rest configuration that is driven by piezoelectric ceramics is designed; the flexible driving part of the micro-feed tool rest is optimized by topology optimization.

In order to solve the problem that an embroidery machine generally uses a straight needle and rotary shuttle to form a lock stitch, which results in the low supply of bobbin thread and frequent bobbin changes, a bobbin thread-hooking mechanism with spatial four-bar linkage is proposed which can achieve a continuous supply of bobbin thread. We provide a reference for solving this embroidery machine practical problem with a spatial four-bar mechanism optimal design method.

The strength of the front axle of tractors used in rough terrain is crucial in countries in which agriculture is widespread. Thus, it is important to analyze the stress experienced by the front axle, as it eventually leads to cracks and premature failure. This study aims to solve the stresses that occur on the housing of the front axle. The results of a finite element analysis and strain gauge measurements were compared, and a correlation was found with 98 % accuracy.

The main contribution of this paper is to establish the dynamic model of the reconfigurable parallel mechanism, a versatile robotic system capable of adapting its configuration to different tasks. The dynamic model facilitates the analysis of the dynamic performance of the mechanism. This comprehensive dynamic model serves as a valuable tool for control algorithm development and the performance optimization of reconfigurable parallel mechanisms in diverse applications.

A time-varying reliability model of parallel systems consisting of beams with crack flaws is developed, considering the dynamic interaction between stress correlation, crack extension correlation, strength degradation correlation, and the random load redistribution. The model can quantitatively analyze the effects of crack extension, strength degradation, load sharing, random load redistribution, and other factors on the time-varying system reliability.