This study presents the two-dimensional(2D)image of a subsurface structure reconstructed using an imaging method based on the photothermal *** photothermal imaging method is based on the deflection method using two la...
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This study presents the two-dimensional(2D)image of a subsurface structure reconstructed using an imaging method based on the photothermal *** photothermal imaging method is based on the deflection method using two lasers:pump and probe lasers.A continuous scanning technique is proposed for 2D(x-and y-directions)surface *** continuous scanning method is compared with the conventional point-by-point scanning technique,and a low-pass fast Fourier transform filter and a Marr-Hildreth detector are found to produce significant *** photothermal imaging method with continuous 2D surface scanning is performed on three copper-resin double-layer samples with different subsurface *** subsurface structures of the copper-resin double-layer samples comprise a square block of 5×5 mm^(2) area and blocks shaped as the alphabet letters“T”and“F”.The letters are 3 mm wide and 10×13 mm^(2) in *** three shapes are 1 mm thick and located at a depth of 0.5 mm from the surface of the copper *** reconstructed photothermal images show an absolute error within 0.122 mm compared with the actual subsurface structure,equivalent to a 2.3%relative error.
Robot teleoperation plays an important role in industrial manufacturing in unknown and dangerous environments beyond human *** telerobotic manufacturing tasks,environmental interaction forces may vary significantly fr...
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Robot teleoperation plays an important role in industrial manufacturing in unknown and dangerous environments beyond human *** telerobotic manufacturing tasks,environmental interaction forces may vary significantly from task to ***,it is crucial to provide operators with the specific proportional feedback of environmental interaction forces to enhance their environmental awareness and manipulation ***,variable time delays and various scales of environmental interaction force feedback seriously affect the system stability,which should be rigorously addressed when designing control *** cope with these difficulties,a position and scaled force tracking control framework is proposed and the LyapunovKrasovskii theory is used to obtain a simple algebraic stability criterion with the scaling factor of the environmental interaction force *** addition,a low-pass filter-based radial basis function neural network is designed to avoid the effect of the measurement noise and the sudden change of the non-passive environmental interaction force on the system *** with different controllers in various telerobotic manufacturing tasks such as heavy lifting,cutting,and polishing,our proposed method achieves better position and scaled force tracking performance.
Titanium matrix composites (TMCs) have high specific strength and stiffness, and high-temperature TMCs can reduce weight by up to 50% when compared with monolithic super alloys while preserving equal stiffness and str...
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Titanium matrix composites (TMCs) have high specific strength and stiffness, and high-temperature TMCs can reduce weight by up to 50% when compared with monolithic super alloys while preserving equal stiffness and strength in jet engine systems for propulsion. The purpose of this work examines the use of mathematical models and learning approaches to optimize response such as porosity and control variables in synthesized hybrid titanium metal matrix composites (HTMMCs) reinforced by B4C-SiC-MoS2-ZrO2. To further understand the impacts of process factors on porosity reduction, the study employs methodologies such as the response surface methodology (RSM), integrated artificial neural networks (ANN), and genetic algorithm (GA). The findings indicate that these strategies have the potential to contribute to the industry. The optimal combination of 7.5wt.% SiC, 7.5wt.% B4C, 7.5wt.% ZrO2, 4wt.% MoS2, and 73.5wt.% Ti compositions was determined utilizing process factors such as milling period (6h), compaction pressure (50MPa), compact duration (50min), sintering temperature (1200°C), and sintering time (2h) as compared to pure Ti grade 5. The mechanical properties of the optimum combination of reinforcement weight percentage and process parameters resulted in a minimum porosity of 0.118%, density of 4.36gcm3, and micro-hardness of 63.4HRC boosted by 1.76%, and compressive strength of 2500MPa increased by 2.6%. In addition, these HTMMCs had a minimal wear rate of 0.176mm3/Nm and a corrosion resistance rate of 2.15×10-4mmpy. The investigation result analysis discovered that the RSM and combined ANN-GA models considerably enhanced the forecasting of multidimensional interaction difficulties in composite material production that were highly statistically connected, with R2 values of 0.9552 and 0.97984. The ANN-GA model provided a 95% confidence range for porosity predictions, which increased the production use of titanium-based particle composites. Furthermore, HMMCs can be u
A novel machining technology,namely ultrasonic assisted jet plasma oxidation modifi-cation face grinding(UAJPMG),was proposed to improve the machinability of the titanium alloy,in which the titanium alloy materials ar...
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A novel machining technology,namely ultrasonic assisted jet plasma oxidation modifi-cation face grinding(UAJPMG),was proposed to improve the machinability of the titanium alloy,in which the titanium alloy materials are modified by plasma oxidation followed by face *** paper introduced the processing principle of UAJPMG and the design of an ultrasonic jet noz-zle to promote plasma *** the ultrasonic jet nozzle produced in-house,the effect of theultrasonic vibration on the plasma intensity was experimentally *** results revealedthat the application of ultrasonic vibration can diminish the thickness of the gas film by elevatingthe jet flow rate,thereby reducing the generation delay time and enhancing the plasma ***,a scratch test was performed to assess the difference in the mechanical strengthbetween the plasma oxide layer and the titanium alloy *** was found that the plasma oxidelayer with a reduced mechanical strength exhibited a deeper scratch depth under the same *** on these,the machining performance under different conditions was examined consid-ering the removed material of the abrasive *** with the removed material was Ti-6Al-4V substrate in conventional face grinding,the ultrasonic assisted plasma oxidized material caninhibit the chip adhesion on the wheel working surface,resulting in a reduction of the grinding forceand the surface roughness and an improvement of the groove shape *** novel machiningtechnology,i.e.,UAJPMG,proposed in this paper might provide a new approach for the precisionmachining of critical components made from titanium alloy.
This article utilizes the biomimetic approach to establish a biologically inspired airfoil profile for an sparrowhawk and compare its lift-to-drag ratio to that of the NACA6409 airfoil profile. The airfoil sections fo...
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Flexible sensors have been developed for the perception of various stimuli. However, complex deformation,usually resulting from forces or strains from multi-axes, can be challenging to measure due to the lack of indep...
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Flexible sensors have been developed for the perception of various stimuli. However, complex deformation,usually resulting from forces or strains from multi-axes, can be challenging to measure due to the lack of independent perception of multiaxial stimuli. Herein, flexible sensors based on the metamaterial membrane with zero Poisson's ratio(ZPR) are proposed to achieve independent detection of biaxial stimuli. By deliberately designing the geometric dimensions and arrangement parameters of elements, the Poisson's ratio of an elastomer membrane can be modulated from negative to positive, and the ZPR membrane can maintain a constant transverse dimension under longitudinal stimuli. Due to the accurate monitoring of grasping force by ZPR sensors that are insensitive to curvatures of contact surfaces, rigid robotic manipulators can be guided to safely grasp deformable objects. Meanwhile, the ZPR sensor can also precisely distinguish different states of manipulators. When ZPR sensors are attached to a thermal-actuation soft robot, they can accurately detect the moving distance and direction. This work presents a new strategy for independent biaxial stimuli perception through the design of mechanical metamaterials, and may inspire the future development of advanced flexible sensors for healthcare, human–machine interfaces and robotic tactile sensing.
Friction is one of the primary factors affecting the tracking performance of a machine tool feed system. Establishing an accurate friction model is the key to achieving friction compensation. Although neural networks ...
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With the drastic reduction of the TSV diameter leading to a critical dimension comparable to the Cu-filled grain size,the grain condition strongly influences the thermo-mechanical behavior of the *** this work,the TSV...
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With the drastic reduction of the TSV diameter leading to a critical dimension comparable to the Cu-filled grain size,the grain condition strongly influences the thermo-mechanical behavior of the *** this work,the TSV-Cu cross-section with different grain sizes is characterized by EBSD,confirming that the sidewall grain size(0.638–1.580μm)is smaller compared to other regions(1.022–2.134μm).A finite element model(FEM)considering copper grains is constructed by using Voronoi diagrams to investigate the effect of sidewall grain size as well as area on the thermo-mechanical behavior during *** material parameters in the FEM are optimized through nanoindentation inversion and considering the mechanical property anisotropy of copper *** yield strengthσy and hardening exponent n of TSV-Cu are 74.6 MPa and *** simulation results indicate that the protrusion of TSV-Cu after annealing tends to increase initially and then decrease with smaller sidewall grain size and *** maximum increase in protrusion caused by the two variables can reach 6.74%and 14.6%,respectively,relative to the average grain ***,the simulation results were validated by quantifying grain boundaries in TSV-Cu samples with varying grain sizes.
In this paper, Magnetite/Saponite（Fe3O4/Sap） composites were prepared by hydrothermal synthesis and coprecipitation. The prepared Fe3O4/sap composites had high purity and good crystallinity, and nano-Fe3O4was unifor...
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In this paper, Magnetite/Saponite（Fe3O4/Sap） composites were prepared by hydrothermal synthesis and coprecipitation. The prepared Fe3O4/sap composites had high purity and good crystallinity, and nano-Fe3O4was uniformly dispersed on the surface of saponite. Moreover, the removal efficiency of Fe3O4/Sap composites for Cr（VI） in water was evaluated. This study revealed the existence of abundant oxygen vacancies and hydroxyl groups on the surface of Saponite. During the synthesis of Fe3O4on the surface of Sap, the multi-directional crystallization can be controlled to increase the reaction activity of the system. Besides, the prepared Fe3O4/Sap composites provided more reactive edges compared to Fe3O4in the process of removing Cr（VI）. The removal amount of Cr（VI） was found to be 17.95 mg/g. The successful preparation of the Fe3O4/Sap composites and the revelation of the Cr（VI） adsorption mechanism are of great significance for the efficient and green removal of heavy metal pollutants in sewage.
A Cu/carbon steel multilayered sheet was quenched, and its tensile properties and electrical conductivity were evaluated. A full martensite structure was developed in the carbon steel layers in the multilayered sheet ...
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