With the continuous development of intelligent technology, robots have entered various industries. Firefighting robots have become a hot topic in the field of firefighting and rescue equipment. For firefighting robots...
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Currently, the machining of hard and brittle fused silica material still relies on material removal by contact-based machining tools. Due to the inherent unevenness of grinding wheels and abrasives, surface defects in...
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To mill fine and well-defined micro-dimpled structures, a machining manner of spiral trajectory tool reciprocating motion, where the tool repeats the process of ‘feed milling±retract±cutting feed±feed ...
To mill fine and well-defined micro-dimpled structures, a machining manner of spiral trajectory tool reciprocating motion, where the tool repeats the process of ‘feed milling±retract±cutting feed±feed milling again' along the spiral trajectory, was proposed. From the kinematics analysis, it is found that the machining quality of micro-dimpled structures is highly dependent on the machining trajectory using spiral trajectory tool reciprocating motion. To reveal this causation, simulation modelling and experimental studies were carried out. A simulation model was developed to quantitatively and qualitatively investigate the influence of the trajectory discretization strategies(constant-angle and constant-arc length) and parameters(discrete angle, discrete arc length, and pitch) on surface texture and residual height of micro-dimpled structures. Subsequently, microdimpled structures were milled under different trajectory discretization strategies and parameters with spiral trajectory tool reciprocating motion. A comprehensive comparison between the milled results and simulation analysis was made based on geometry accuracy, surface morphology and surface roughness of milled dimples. Meanwhile, the errors and factors affecting the above three aspects were analyzed. The results demonstrate both the feasibility of the established simulation model and the machining capability of this machining way in milling high-quality micro-dimpled structures. Spiral trajectory tool reciprocating motion provides a new machining way for milling micro-dimpled structures and micro-dimpled functional surfaces. And an appropriate machining trajectory can be generated based on the optimized trajectory parameters, thus contributing to the improvement of machining quality and efficiency.
Lattice metamaterials made of stiff polymers, ceramics, and metals have been extensively designed to reproduce the mechanical behaviors of biological tissues, holding promising applications in biomedical devices and t...
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Accurate prediction of aeroengine Remaining Useful Life (RUL) is critical for ensuring flight safety, minimizing maintenance costs, and improving operational efficiency. This study proposes a novel model, the Fourier-...
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Dielectric elastomer actuators (DEAs) require high energy density to simultaneously achieve high mechanical output while enabling compact and lightweight actuator design. However, the realization of high energy densit...
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Dielectric elastomer actuators (DEAs) require high energy density to simultaneously achieve high mechanical output while enabling compact and lightweight actuator design. However, the realization of high energy densit...
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The development of non-toxic and flexible polymer-based shielding composites has become a research hotspot due to the severe harm of γ ray to living organisms, mechanical equipment, and environment. However, the γ-r...
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The development of non-toxic and flexible polymer-based shielding composites has become a research hotspot due to the severe harm of γ ray to living organisms, mechanical equipment, and environment. However, the γ-ray shielding performance of polymer-based composites in high-energy range remains unsatisfactory. Herein, FLUKA Monte Carlo simulations capable of visualizing γ-photon transport behaviors are investigated in Bi 2 O 3 /PP and WO 3 /PP multi-layer composites with various layered configurations. The simulation results reveal significant anisotropic attenuation effects on shielding characteristics caused by layered configurations and incident path of γ-photons relative to the interface position. Subsequently, single-layer, AB, and sandwich-like ABA composites with a fixed thickness of 2.0 mm are experimentally fabricated via melt-mixing and hot press methods. At 1332 keV, sandwich-like WPPBPPWPP composite (WO 3 /PP outer layers + Bi 2 O 3 /PP core) achieves linear attenuation coefficients and radiation protection efficiency of 0.31 cm −1 and 6 %, respectively, which are 29 % higher than those of single-layer composite. These improvements originate from multiple scattering induced by interlayer interface. Additionally, layered configurations with externally placed high-density fillers (WO 3 ) and internally placed high atomic number fillers (Bi 2 O 3 ) further promote γ-photon attenuation in high-energy range. Experimental results validate the anisotropic shielding trends observed in MC simulations. Moreover, multi-layer composites demonstrate significantly improved energy storage capacity, thermal stability, and oxidation resistance while maintaining comparable to those of single-layer composites. This work provides a scalable strategy for developing non-toxic and flexible shielding materials applicable in nuclear protection, medical devices, and aerospace systems, where lightweight and efficient radiation attenuation are critical.
In large-scale manufacturing and automation, cooperative robotic manipulation requires lower-level controllers to generate specific position or force commands based on real-time information. However, adapting these co...
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Dynamic modeling is essential for serial manipulators’ design and control. Multi-body dynamics simulators, such as SIMULINK and Adams, can precisely replicate a robot's dynamic behavior but are incapable of deter...
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