This study focused on the buckling characteristics of egg-shaped shells with single crack and double cracks under axial ***,the geometric parameters of the egg-shaped shell were designed,and a numerical model of the e...
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This study focused on the buckling characteristics of egg-shaped shells with single crack and double cracks under axial ***,the geometric parameters of the egg-shaped shell were designed,and a numerical model of the egg-shaped shell was ***,the initial crack was introduced into the equatorial weld of the egg-shaped shell,and the effects of the crack on the buckling characteristics under different wall thicknesses were explored,as were the effects of the single crack direction,double crack angle and spacing on the buckling ***,crack-free,single crack and double crack egg-shaped shells were fabricated from Q235 *** buckling loads and failure modes of the three egg-shaped shells were obtained via axial compression *** numerical critical buckling loads and buckling modes were compared with the experimental results to verify the accuracy of the numerical *** results of this study are valuable for the design of egg-shaped shells under axial loading.
Rapid urbanization and industrialization have led to the increased generation of electronic waste (E-waste) throughout the world, and the proper management of this hazardous E-waste is of utmost challenge nowadays. Ba...
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Heat exchangers have the potential for various engineering applications,and their performance is enriched by surface *** proposed system enriches the heat exchanger's performance by adapting a peened stainless ste...
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Heat exchangers have the potential for various engineering applications,and their performance is enriched by surface *** proposed system enriches the heat exchanger's performance by adapting a peened stainless steel(SS)surface blasted with copper,grinding,sand,and *** influences peened SS surface modified with a copper blast,grinding,sandblast,and iron blast on the surface morphology of shell and tube heat exchanger surface(STHE)is analyzed via tungsten heated cathode electron gun featured scanning electron microscope and observed coarse grain *** SS surface featured STHE performance is experimentally evaluated by different flow rates(30,60,90,and 120 L/min)underwater fluid medium functioned by the temperature ranges of 25-75℃ and its results are compared with computational fluid dynamic(CFD)/heat transfer research(HTRI)analyzed *** 60 L/min flow rate was spotted as an optimum value for both shell and tube side *** STHE is operated with a 60 L/min flow rate under the different peened surfaces and evaluated its Stanton number,Nusselt number,logarithmic mean temperature difference(LMTD),overall heat transfer coefficient,number of transfer units(NTU),effectiveness,and exergy *** iron blasted SS peened surface was observed to have better SHTE performance like Stanton number(0.0012),Nusselt number(2180),reduced LMTD of 31℃,improved overall heat transfer co-efficient of 2400 W/(m^(2)·K),better NTU of 0.5532,good effectiveness value of 0.45162,and hiked exergy efficiency of 10% respectively.
This work aims to present and explore thermal management techniques for the wire arc additive manufacturing(WAAM)of IN718 *** heat can be mitigated via air or water *** this study,the material was deposited under four...
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This work aims to present and explore thermal management techniques for the wire arc additive manufacturing(WAAM)of IN718 *** heat can be mitigated via air or water *** this study,the material was deposited under four different heat-input conditions with air or water *** air cooling,the layer is deposited in a normal atmospheric air environment,whereas with water cooling,the material is deposited inside a water tank by varying the water *** validate the air and water cooling thermal management techniques,IN718 single-pass and multilayer linear walls were deposited using the bidirectional gas metal arc welding based WAAM setup under four different heat input *** the deposition of single layers,the temperature profiles were recorded,and the geometric and microstructural features were *** multilayer wall structures,the mechanical properties(hardness,tensile strength,and elongation)were determined and assessed using the corresponding microstructural features explored through scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),and electron backscatter diffraction(EBSD)*** microstructure observed through SEM analysis in the building direction was found to be nonhomogenous compared with that in the deposition ***,water cooling was found to govern bead characteristics,such as wall width and *** grain size and anisotropy of the mechanical properties also decreased in the water-cooled ***,water cooling is an economical and efficient method to mitigate excessive heat accumulation in WAAM-deposited IN718.
For improving the tribological performance,the textured composite solid lubricant coating was prepared on the surface of Ti-6Al-4V(TC4).The effects of composite coating with different texture densities on the tribolog...
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For improving the tribological performance,the textured composite solid lubricant coating was prepared on the surface of Ti-6Al-4V(TC4).The effects of composite coating with different texture densities on the tribological properties of TC4 were *** results show that the coating improves the microhardness of TC4 surface,and appropriate texture density effectively suppresses the stress of contact interface so that the average friction coefficient of TC4-based composite solid lubricant coating with 25%wavy texture density sample(TCWs-SW25)is 50.24%lower than that of TC4,and the average wear loss is reduced by 97.66%.The enhancement of contact interface performance comes from the transfer effect of lubricants to reduce the number of interfacial asperities,thereby improves the friction and wear properties and inhibits vibration and noise of TC4.
Incremental sheet forming is a dieless forming process. Innovative analysis of deformations in the SPIF process, utilizing four distinct sets of deformed structures. Each set consists of four deformed shapes that are ...
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The dynamic response is a critical performance indicator of air-cooled fuel cells, directly affecting their operation's stability and reliability. This paper experimentally investigated the impact of different ope...
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The dynamic response is a critical performance indicator of air-cooled fuel cells, directly affecting their operation's stability and reliability. This paper experimentally investigated the impact of different operating conditions on the dynamic response characteristics of the air-cooled proton exchange membrane fuel cell(PEMFC) stack. The overvoltage of fuel cells at higher ambient temperatures is smaller after loading, and it takes a shorter time for fuel cells to recover to a stable level. Different air supply modes were investigated, results show that increasing the cathode gas flow rate helps reduce the overshoot voltage of the air-cooled PEMFC stack. A higher cathode flow rate enhances the oxygen concentration at the catalyst layer, helping to supplement the local gas shortage. In addition, as the gas pressure inside the stack is slightly lower than the ambient pressure when the air-cooled PEMFC operates with the exhaust mode, the overshoot voltage of the exhaust air supply mode is 15.8 %higher than that of the blow airflow mode under the same air fan speed(4500r/min). Increasing the load change rate leads to insufficient local gas supply without enough time to replenish, causing the cell's overshoot voltage to rise; the more significant the load change rate, the greater the cell's overshoot voltage. Reducing the anode pulse purging interval can reduce the cell output voltage fluctuation with limited effect.
Sliding-mode triboelectric nanogenerator(S-TENG)is based on the coupling of triboelectrification and electrostatic induction,converting electrical energy from sliding *** micro-textures into the sliding surface,and ad...
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Sliding-mode triboelectric nanogenerator(S-TENG)is based on the coupling of triboelectrification and electrostatic induction,converting electrical energy from sliding *** micro-textures into the sliding surface,and adjusting the angle between the texture and sliding direction(direction angle)may achieve performance anisotropy,which provides novel ideas for optimizing the tribology and electrification performance of *** guide the performance optimization based on the anisotropy,in this paper,groove micro-textures were fabricated on the surface of S-TENG,and anisotropic tribology and electrification performance were obtained through changing the direction *** on the surface analysis and after-cleaning tests,the mechanism of the anisotropy was *** is shown that the anisotropy of friction coefficient can be attributed to the changes of texture edge induced resistance and groove captured wear debris,while the voltage anisotropy is due to the variations of debris accumulated on the sliding interface and the resulting charge *** the selected 0°–90°direction angles,S-TENG at angle of 90°exhibits relatively small stable friction coefficient and high open-circuit voltage,and thus it is recommended for the performance *** open-circuit voltage is not directly associated with the friction coefficient,but closely related to the wear debris accumulated on the sliding *** study presents a simple and convenient method to optimize the performance of S-TENG,and help understand the correlation between its tribology and electrical performance.
Energy is crucial to progress toward development, modernization, and economic prosperity. Energy and water are both crucial to human survival and play significant roles in the growth and development of society. The ne...
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Magnesium,the lightest structural metal,is increasingly adopted in various industries,particularly automotive and aerospace,underscores the economic importance of magnesium due to its high specific strength,stiffness,...
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Magnesium,the lightest structural metal,is increasingly adopted in various industries,particularly automotive and aerospace,underscores the economic importance of magnesium due to its high specific strength,stiffness,and excellent damping ***,the primary production of magnesium is highly energy-intensive and environmentally ***-state recycling via plastic deformation techniques offers a promising alternative to manufacturing ultrafine-grained magnesium samples with superior *** the lack of reviews on the mechanisms of grain refinement during the solid-state recycling of magnesium and its alloys,this paper addresses this gap by offering detailed *** an extensive review of relevant literature,the current paper highlights how plastic deformation techniques facilitate grain refinement during the solid-state recycling of magnesium chips and *** this regard,a grain refinement mechanism during SSR of Mg and its alloys is proposed by the authors,to guide future advancements in sustainable magnesium recycling *** will clarify the benefits of solid-state recycling over traditional methods,such as higher metal yields and better mechanical properties.
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