Wenjun Meng

Aramid fiber is increasingly regarded as an important skeleton material in the conveyor belt industry. However, its application is limited by problems such as short splice service life and low strength retention. This study investigates the finger splice of an aramid rubber conveyor belt. A finite element model was established to analyze the effects of different rubber hardness values (60, 65, 70, 75), environmental temperatures (−20 to 40 °C), and finger widths (10 mm, 12 mm, 15 mm, 20 mm, 30 mm) on splice mechanical performance. The results show that the maximum stress is concentrated at the end surfaces of the reinforcement layer and the fingertips of the skeleton material. The splice strength increases with higher rubber hardness but decreases with rising environmental temperature. To improve splice strength, the rubber hardness and environmental temperature should be controlled within 60–70 and 0–20 °C, respectively. Although reducing finger width increases splice strength, excessively small widths lead to stress concentration and manufacturing difficulties. Therefore, finger width selection should consider actual working conditions. The experimental results are compared with simulation results, and the trend consistency verifies the correctness of the simulation. This study provides a theoretical basis for parameter selection and structural design of the splice under various working conditions.

This study employed a three-level cyclic loading path to investigate the mechanical behavior of sandstone across different failure stages under constant-amplitude cyclic loading. The loading path encompassed the initial crack closure, elastic deformation, and crack propagation stages. The mechanical behavior at each stage was characterized by analyzing deformation response, energy evolution, and acoustic emission (AE) characteristics. The results indicated that the mechanical response of the rock sample exhibited distinct stage-specific characteristics. In the unstable crack propagation stage, the elastic modulus decreased rapidly, the damage energy increased continuously, and both the number of AE events and the associated energy increased significantly. The average peak stress reduction per unit cycle during the unstable crack propagation stage exceeded that during the elastic deformation stage by more than two orders of magnitude. The elastic modulus was highest in the stable crack propagation stage, followed by the elastic deformation stage, and lowest in the initial crack closure stage. Throughout the crack propagation stage, each stress drop was accompanied by a pronounced surge in AE counts and energy, indicating that these stress reductions resulted from the localized propagation and coalescence of internal cracks.

Based on the problem of incomplete mining of Additive Manufacturing (AM) potential caused by the limitations of current Design for Additive Manufacturing (DFAM) methods, this paper proposes to integrate Additive Manufacturing and axiomatic design to obtain the global conceptual design method of products to be manufactured with AM. In response to the lower process dependence of AM technology compared to traditional processes, two integration measures of “influence region division” and “process domain forward” are proposed, and finally, the axiomatic design process for AM is obtained. Taking the assembly-free integrated design of mechanical fingers imitating dexterous hands as an example, the conceptual design method studied was validated. The application of innovative features such as flexible finger joints and lattice-filled finger joints shows that the design method proposed in this paper can deeply tap into the manufacturing potential of AM, achieve lightweight and integrated molding of products, which provides useful references for designers.

Wear-resistant steel/carbon steel composite plates not only have the double performance advantages of high strength and wear resistance but can also reduce energy consumption and production costs. Based on a 50% reduction rate, the wear resistance of the BTW1/Q345 composite was studied at different annealing temperatures, and the dry friction and wear tests of the BTW1/Q345 composite at different annealing temperatures were carried out using RETC MFT-5000. By using the white-light interference three-dimensional surface profiler, scanning electron microscope (SEM), and backscattered electron diffraction (EBSD) technology, we carried out a detailed analysis of the macroscopic and microscopic morphology and wear mechanism of wear traces at different annealing temperatures. The effects of the annealing process on the thickness and composition of the wear layer were studied, and the causes of wear failure were analyzed based on the results of scanning electron microscopy. It was found that as the annealing temperature gradually increased, the particle size near the scratch of BTW1 in the wear-resistant layer of the composite plate became smaller. On this basis, the effects of different annealing temperatures on the friction and wear characteristics of the composite plate were further studied. At the annealing temperature of 860 ° C, the wear resistance of the material was the best.

The screw flight, spiral blade welded on the axial cylinder, is the core component of the screw ship unloader and can be seriously worn by the materials during long-term conveying. The damaged screw flight will make the screw ship unloader unable to unload materials or even lead to an accident. However, the existing wear model cannot be directly applied to predict the wear of the screw flight under different working conditions. Hence, we established a new screw flight wear model based on the Archard wear model and Continuous Medium Hypothesis to predict the service life of the screw flight. Three influencing factors, including speed, filling rate, and pitch, were selected to study the wear law of the screw flight, and the wear law was verified by EDEM simulation. Results indicate that the simulation results affected by the changes in various factors were consistent with the calculation model. With the increase of rotation speed and filling rate, the screw flight wear rate increased. Nevertheless, with the increase of pitch, the screw flight wear rate first increased and then decreased. The screw flight wear model can be used to calculate the wear rate under different working conditions for the screw flight life prediction.