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Multi-Objective Optimization of VBHF in Deep Drawing Based on the Improved QO-Jaya Algorithm

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Chinese Journal of Mechanical Engineering 2024年第1期37卷 189-202页

作者： Xiangyu Jiang Zhaoxi Hong Yixiong Feng Jianrong Tan State key laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310027China Key Laboratory of Advanced Manufacturing Technology of Zhejiang Province Zhejiang UniversityHangzhou 310027China Ningbo Innovation Center Zhejiang UniversityNingbo 315100China

Blank holder force(BHF)is a crucial parameter in deep drawing,having close relation with the forming quality of sheet metal.However,there are different BHFs maintaining the best forming effect in different stages of deep drawing.The variable blank holder force(VBHF)varying with the drawing stage can overcome this problem at an extent.The optimization of VBHF is to determine the optimal BHF in every deep drawing stage.In this paper,a new heuristic optimization algorithm named Jaya is introduced to solve the optimization efficiently.An improved“Quasi-oppositional”strategy is added to Jaya algorithm for improving population diversity.Meanwhile,an innovated stop criterion is added for better convergence.Firstly,the quality evaluation criteria for wrinkling and tearing are built.Secondly,the Kriging models are developed to approximate and quantify the relation between VBHF and forming defects under random sampling.Finally,the optimization models are established and solved by the improved QO-Jaya algorithm.A VBHF optimization example of component with complicated shape and thin wall is studied to prove the effectiveness of the improved Jaya algorithm.The optimization results are compared with that obtained by other algorithms based on the TOPSIS method.

关键词： Variable blank holder force Multi-objective optimization QO-Jaya algorithm Algorithm stop criterion

Numerical modeling and experimental study of microstamping process for fabricating microchannels using thin sheets of titanium

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Journal of zhejiang University-Science A(Applied Physics & Engineering) 2023年第12期24卷 1079-1095页

作者： Wenze MAO Yancheng WANG Deqing MEI Lingfeng XUAN Caiying ZHOU State key laboratory of Fluid Power and Mechatronic Systems School of Mechanical EngineeringZhejiang UniversiyHangzhou 310058China Key Laboratory of Advanced Manufacturing Technology of Zhejiang Province School of Mechanical EngineeringZhejiang UniversityHangzhou 310058China

Ultra-thin sheets of titanium for fabricating microchannels have been used in fuel cells due to their good corrosion resistance and high strength-weight ratio. This paper presents a constitutive model for studying the anisotropy effects of pure titanium(CP-Ti) sheet on the springback behavior and forming properties during the microstamping process. Thin sheets of CP-Ti specimens with different orientations were examined using uniaxial tensile tests to assess the effects of anisotropy on their mechanical properties. Then an anisotropic constitutive model considering the off-axis elastic modulus was developed based on orthotropic elasticity and Hill's yield criterion. Numerical modeling and simulation of the microstamping process for fabricating multi-channel structures were performed. The effects of anisotropy on the springback of multi-channels were investigated and compared with experimental results;the effects of tool dimension parameters on the formability of microchannel structures were also analyzed. The results showed that the anisotropy of thin titanium sheets causes various degrees of forming loads and springback in the microstamping of microchannels at different orientations. This study accurately predicts the springback of thin titanium sheet used to fabricate microchannel structures and is a good guide to the formation of such structures.

关键词： Titanium sheets Microstamping Anisotropy Constitutive model Springback

数控机床几何和主轴误差对精密车削端面表面质量的影响（英文）

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Journal of zhejiang University-Science A(Applied Physics & Engineering) 2015年第5期16卷 371-386页

作者： Jiang-xin YANG Jia-yan GUAN Xue-feng YE Bo LI Yan-long CAO Key Laboratory of Advanced Manufacturing Technology of Zhejiang Province Zhejiang University The State key laboratory of Fluid Power Transmission and Control Zhejiang University

目的:建立端面车削加工模型和不同误差下车削表面形貌的仿真方法,分析车床误差与切削加工表面形貌之间的关联关系。创新点:1.考虑机床几何误差和主轴运动误差的影响,将车床综合运动误差模型引入到表面形貌仿真中,建立车削端面表面形貌... 详细信息

目的:建立端面车削加工模型和不同误差下车削表面形貌的仿真方法,分析车床误差与切削加工表面形貌之间的关联关系。创新点:1.考虑机床几何误差和主轴运动误差的影响,将车床综合运动误差模型引入到表面形貌仿真中,建立车削端面表面形貌三维仿真模型;2.研究主轴误差和几何误差对表面粗糙度的影响,分析各项误差影响的显著性水平。方法:1.分析典型的车床结构及误差元素,建立车床综合误差模型(表1、图1和图2);2.分析车削加工表面成型机理,研究车床误差对端面车削表面质量的影响规律,建立两者之间的数学映射关系(图3和图6);3.基于正交实验法设计仿真实验,分析不同误差的影响趋势(图9、图10、表3和表4)。结论:1.车床几何误差和主轴误差对端面车削加工表面形貌影响很大,其中导轨直线度会线性地叠加到车削端面的径向廓上;主轴绕y轴的转角误差、导轨绕y轴的转角误差和车床导轨间的垂直度误差会使车削端面的径向轮廓出现倾斜现象;主轴的位移误差会导致车削表面产生脊峰。2.加工表面粗糙度受主轴位移误差的振幅和频率影响较大。

关键词：表面质量几何误差主轴误差齐次变换矩阵主成分分析车削端面

Effect of gap and overlap on mode Ⅱ interlaminar fracture toughness of automated fiber placement prepreg laminates

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Chinese Journal of Aeronautics 2023年第6期36卷 390-401页

作者： Fan ZHANG Xin LIU Yaoyao YE Qisen CHEN Qiang XU Yunbo BI China State key laboratory of Fluid Power and Mechatronic System School of Mechanical EngineeringZhejiang UniversityHangzhou 310027China Key Laboratory of Advanced Manufacturing Technology of Zhejiang Province School of Mechanical EngineeringZhejiang UniversityHangzhou 310027China

Automated Fiber Placement(AFP)technology facilitates the manufacturing process of composite structures with complex geometry owing to its high efficiency and accuracy.However.the unavoidable imperfections induced by the automated layup method bring challenges to the stability of the final mechanical properties of composites.The influence of AFP-induced gaps and overlaps on the modeⅡinterlaminar fracture process of oven-cured laminates is experimentally investigated and explicitly revealed.End-Notched Flexure(ENF)tests were performed to measure the interlaminar fracture toughness of unidirectional laminates under three different defect configurations,namely"Gap""Overlap"and"Gap&Overlap".A marginal decline(about-1.2%in non-precracked tests,-5.1%in precracked tests)and an obvious increase(about 15.2%in nonprecracked tests,5.2%in precracked tests)in fracture toughness were observed for the"Gap"group and the"Overlap"group,respectively.Fractographic studies which involve the metallographic observation and Scanning Electron Microscopy(SEM)observation revealed that the increases in fracture area and crack length helped improve the fracture toughness of the Overlap"group.However,the resin-rich area with high porosity induced by gaps was detrimental to the delamination resistance.To capture the interlaminar stress distribution local to imperfections,a three-dimensional numerical model was established.Gap defects facilitate the local delamination process,and the overlap defect postpones the damage onset and the propagation.

关键词： Automated Fiber Placement(AFP) Defects Delamination Fracture toughness Laminates

Thermal management for thermoset automated fiber placement based on infrared heater structure arrangement

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Chinese Journal of Aeronautics 2022年第1期35卷 173-183页

作者： Han WANG Weiwei WANG Haijin WANG Huiyue DONG Yinglin KE A State key laboratory of Fluid Power and Mechatronic System School of Mechanical EngineeringZhejiang UniversityHangzhou 310027China Key Laboratory of Advanced Manufacturing Technology of Zhejiang Province School of Mechanical EngineeringZhejiang UniversityHangzhou 310027China

Layup temperature is a vital factor that affects the production quality of automated fiber placement for thermoset composites.For high quality production,this paper proposes a new prediction model of layup temperature by considering the structure of infrared heater of automatic fiber placement equipment.The model was first verified by comparing with the temperature results of layup experiments.Then a prediction on the effects of heater structure arrangement on layup temperature was conducted in the model.The research shows that the length of infrared tube and the radian of reflective-film have significant influences,rather than other parameters.According to this investigation,a heater structure-based heating strategy was presented in the paper to efficiently achieve constant temperature control in variable speed layup process.

关键词： Automated fiber placement Heating strategy optimization Infrared heater structure Thermal management Variable speed

Build orientation determination of multi-feature mechanical parts in selective laser melting via multi-objective decision making

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机械工程前沿:英文版 2023年第2期18卷 227-251页

作者： Hongsheng SHENG Jinghua XU Shuyou ZHANG Jianrong TAN Kang WANG Engineering Research Center for Design Engineering and Digital Twin of zhejiang province Zhejiang UniversityHangzhou 310027China State key laboratory of Fluid Power and Mechatronic Systems Hangzhou 310027China Key Laboratory of Advanced Manufacturing Technology of Zhejiang Province Hangzhou 310027China

Selective laser melting(SLM)is a unique additive manufacturing(AM)category that can be used to manufacture mechanical parts.It has been widely used in aerospace and automotive using metal or alloy powder.The build orientation is crucial in AM because it affects the as-built part,including its part accuracy,surface roughness,support structure,and build time and cost.A mechanical part is usually composed of multiple surface features.The surface features carry the production and design knowledge,which can be utilized in SLM fabrication.This study proposes a method to determine the build orientation of multi-feature mechanical parts(MFMPs)in SLM.First,the surface features of an MFMP are recognized and grouped for formulating the particular optimization objectives.Second,the estimation models of involved optimization objectives are established,and a set of alternative build orientations(ABOs)is further obtained by many-objective optimization.Lastly,a multi-objective decision making method integrated by the technique for order of preference by similarity to the ideal solution and cosine similarity measure is presented to select an optimal build orientation from those ABOs.The weights of the feature groups and considered objectives are achieved by a fuzzy analytical hierarchy process.Two case studies are reported to validate the proposed method with numerical results,and the effectiveness comparison is presented.Physical manufacturing is conducted to prove the performance of the proposed method.The measured average sampling surface roughness of the most crucial feature of the bracket in the original orientation and the orientations obtained by the weighted sum model and the proposed method are 15.82,10.84,and 10.62μm,respectively.The numerical and physical validation results demonstrate that the proposed method is desirable to determine the build orientations of MFMPs with competitive results in SLM.

关键词： selective laser melting(SLM) build orientation determination multi-feature mechanical part(MFMP) fuzzy analytical hierarchy process multi-objective decision making(MODM)

Multimaterial Embedded 3D Printing of Composite Reinforced Soft Actuators

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Research 2023年第4期2023卷 727-737页

作者： Zhenhua Wang Boyu Zhang Qu He Hao Chen Jizhe Wang Yuan Yao Nanjia Zhou Weicheng Cui key laboratory of Coastal Environment and Resources of zhejiang province School of EngineeringWestlake UniversityHangzhouZhejiang ProvinceChina Institute of advanced technology Westlake Institute for Advanced StudyHangzhouZhejiang ProvinceChina Research Center for Industries of the Future and Key Laboratory of 3D Micro/Nano Fabrication and Characterization of Zhejiang ProvinceSchool of EngineeringWestlake UniversityHangzhouZhejiang ProvinceChina

Soft pneumatic actuators(SPAs)have attracted enormous attention in the growing field of robotics.Among different SPAs,composite reinforced actuators(CRAs)are widely used because of their simple structure and high controllability.However,multistep molding,a time-consuming method,is still the predominant fabrication method.Here,we propose a multimaterial embedded printing method(ME3P)to fabricate CRAs.In comparison with other 3-dimensional printing methods,our method improves fabrication flexibility greatly.Via the design and fabrication of the reinforced composites’patterns and different geometries of the soft body,we demonstrate actuators with programmable responses(elongation,contraction,twisting,bending,and helical and omnidirectional bending).Finite element analysis is employed for the prediction of pneumatic responses and the inverse design of actuators based on specific actuation needs.Lastly,we use tube-crawling robots as a model system to demonstrate our ability to fabricate complex soft robots for practical applications.This work demonstrates the versatility of ME3P for the future manufacturing of CRA-based soft robots.

关键词： composites composite printing

Capillary electroosmosis properties of water lubricants with different electroosmotic additives under a steel-on-steel sliding interface

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Friction 2022年第7期10卷 1019-1034页

作者： Bohua FENG Zhiqiang LUAN Tao ZHANG Jiawei LIU Xiaodong HU Jiju GUAN Xuefeng XU key laboratory of Special Purpose Equipment and advanced manufacturing technology Ministry of Education&Zhejiang ProvinceZhejiang University of TechnologyHangzhou 310023China College of Mechanical Engineering Changshu Institute of TechnologyChangshu 215500China

The process of lubricant penetration into frictional interfaces has not been fully established,hence compromising their tribological performance.In this study,the penetration characteristics of deionized water(DI water)containing an electroosmotic suppressant(cetyltrimethylammonium bromide(CTAB))and an electroosmotic promoter(sodium lauriminodipropionate(SLI)),were investigated using steel-onsteel friction pairs.The results indicated that the lubricant with electroosmotic promoter reduced the coefficient of friction and wear scar diameter,whereas that with an electroosmotic suppressant exhibited an opposite behavior compared with DI water.The addition of SLI promoted the penetration of the DI water solution,thus resulting in the formation of a thick lubricating film of iron oxide at the sliding surface.This effectively reduced the abrasion damage,leading to a lower coefficient of friction and wear loss.

关键词： electroosmosis friction interface electroosmotic additives water lubricants tribological performance

Granular Ionogel Particle Inks for 3D Printed Tough and Stretchable Ionotronics

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Research 2024年第1期2023卷 429-442页

作者： Yuan Yao Yue Hui Zhenhua Wang Hehao Chen Heng Zhu Nanjia Zhou key laboratory of 3D Micro/Nano Fabrication and Characterization of zhejiang province School of EngineeringWestlake UniversityHangzhou 310024Zhejiang ProvinceChina Institute of advanced technology Westlake Institute for Advanced StudyHangzhou 310024Zhejiang ProvinceChina School of Chemical Engineering and advanced Materials the University of AdelaideAdelaide 5005South AustraliaAustralia State key laboratory of Fluid Power&Mechatronic System Key Laboratory of Soft Machines and Smart Devices of Zhejiang ProvinceCenter for X-MechanicsDepartment of Engineering MechanicsZhejiang UniversityHangzhou 310027China

Ionogels have garnered great attention as promising soft conducting materials for the fabrication of flexible energy storage devices,soft actuators,and ionotronics.However,the leakage of the ionic liquids,weak mechanical strength,and poor manufacturability have greatly limited their reliability and applications.Here,we propose a new ionogel synthesis strategy by utilizing granular zwitterionic microparticles to stabilize ionic liquids.The ionic liquids swell the microparticles and physically crosslink microparticles via either electronic interaction or hydrogen bonding.Further introducing a photocurable acrylic monomer enables the fabrication of double-network(DN)ionogels with high stretchability(>600%)and ultrahigh toughness(fracture energy>10 kJ/m^(2)).The synthesized ionogels exhibit a wide working temperature of−60 to 90℃.By tuning the crosslinking density of microparticles and physical crosslinking strength of ionogels,we synthesize DN ionogel inks and print them into three-dimensional(3D)motifs.Several ionogelbased ionotronics are 3D printed as demonstrations,including strain gauges,humidity sensors,and ionic skins made of capacitive touch sensor arrays.Via covalently linking ionogels with silicone elastomers,we integrate the ionogel sensors onto pneumatic soft actuators and demonstrate their capacities in sensing large deformation.As our last demonstration,multimaterial direct ink writing is harnessed to fabricate highly stretchable and durable alternating-current electroluminescent devices with arbitrary structures.Our printable granular ionogel ink represents a versatile platform for the future manufacturing of ionotronics.

关键词： crosslinking utilizing gauge