Lightweight thin-walled structures with lattice infill are widely desired in satellite for their high stiffness-to-weight ratio and superior buckling strength resulting fromthe sandwich effect.Such structures can be f...Lightweight thin-walled structures with lattice infill are widely desired in satellite for their high stiffness-to-weight ratio and superior buckling strength resulting fromthe sandwich effect.Such structures can be fabricated bymetallic additive manufacturing technique,such as selective laser melting(SLM).However,the maximum dimensions of actual structures are usually in a sub-meter scale,which results in restrictions on their appliance in aerospace and other fields.In this work,a meter-scale thin-walled structure with lattice infill is designed for the fuel tank supporting component of the satellite by integrating a self-supporting lattice into the thickness optimization of the thin-wall.The designed structure is fabricated by SLM of AlSi10Mg and cold metal transfer welding technique.Quasi-static mechanical tests and vibration tests are both conducted to verify the mechanical strength of the designed large-scale lattice thin-walled structure.The experimental results indicate that themeter-scale thin-walled structure with lattice infill could meet the dimension and lightweight requirements of most spacecrafts.展开更多
To investigate the vibration principle in machining thin-walled components, a dynamic model for end milling of flexible structures is built based on considering the variations in the dynamic chip thickness and the dif...To investigate the vibration principle in machining thin-walled components, a dynamic model for end milling of flexible structures is built based on considering the variations in the dynamic chip thickness and the differences between up-milling and down-milling. Two milling experiments verify the model. Experimental results show that the model can predict the milling force and displacements simultaneously in the dynamic milling process.展开更多
A new generation of fluid pressure forming technology has been developed for the three typical structures of tubes,sheets,and shells,and hard-to-deform material components that are urgently needed for aerospace,aircra...A new generation of fluid pressure forming technology has been developed for the three typical structures of tubes,sheets,and shells,and hard-to-deform material components that are urgently needed for aerospace,aircraft,automobile,and high-speed train industries.in this paper,an over all review is introduced on the state of the art in fundamentals and processes for lower-pressure hydroforming of tubular components,double-sided pressure hydroforming of sheet components,die-less hydroforming of ellipsoidai shells,and dual hardening hot medium forming af hard-to-deform materiais Particular attention is paid to deformation behavior,stress state adjustment,defect prevention,and typical applications.In addition,future development directions of fluid pressure forming technology are discussed,including hyper lower-loading forming for ultra-large non-uniform components,precision for ming for intermetallic compound and high-entropy alloy components,intelligent process and equipment,and precise finite element simulation of inhomogeneous and strong anisotropic thin shells.展开更多
Fixture locating layout has a direct and influential impact on aeronautical thin-walled component(ATWC)manufacturing quality.The purpose is to develop a topological optimization method for ATWC fixture locating layout...Fixture locating layout has a direct and influential impact on aeronautical thin-walled component(ATWC)manufacturing quality.The purpose is to develop a topological optimization method for ATWC fixture locating layout to minimize the manufacturing deformation.Firstly,a topological optimization model that takes the stiffness of ATWC as the objective function and the volume of the locating structure as the constraint is established.Secondly,ATWC and the locating structure are regarded as an integrated entity,and the variable-density method based topological optimization approach is adopted for the optimization of the locating structure using ABAQUS topology optimization module(ATOM).Thirdly,through a subsequent model reconstruction referring to the obtained topological structure,the optimal fixture locating layout is achieved.Finally,a case study is conducted to verify the proposed method and the comparison results with firefly algorithm(FA)coupled with finite element analysis(FEA)indicate that the number and positions of the locators for ATWC can be optimized simultaneously and successfully by the proposed topological optimization model.展开更多
Complex thin-walled titanium alloy components play a key role in the aircraft,aerospace and marine industries,offering the advantages of reduced weight and increased thermal resistance.The geometrical complexity,dimen...Complex thin-walled titanium alloy components play a key role in the aircraft,aerospace and marine industries,offering the advantages of reduced weight and increased thermal resistance.The geometrical complexity,dimensional accuracy and in-service properties are essential to fulfill the high-performance standards required in new transportation systems,which brings new challenges to titanium alloy forming technologies.Traditional forming processes,such as superplastic forming or hot pressing,cannot meet all demands of modern applications due to their limited properties,low productivity and high cost.This has encouraged industry and research groups to develop novel high-efficiency forming processes.Hot gas pressure forming and hot stamping-quenching technologies have been developed for the manufacture of tubular and panel components,and are believed to be the cut-edge processes guaranteeing dimensional accuracy,microstructure and mechanical properties.This article intends to provide a critical review of high-efficiency titanium alloy forming processes,concentrating on latest investigations of controlling dimensional accuracy,microstructure and properties.The advantages and limitations of individual forming process are comprehensively analyzed,through which,future research trends of high-efficiency forming are identified including trends in process integration,processing window design,full cycle and multi-objective optimization.This review aims to provide a guide for researchers and process designers on the manufacture of thin-walled titanium alloy components whilst achieving high dimensional accuracy and satisfying performance properties with high efficiency and low cost.展开更多
Sheet-bulk metal forming(SBMF)is a promising process for manufacturing complex sheet components with functional elements.In this study,the entire forming process for a typical thin-walled component with external geari...Sheet-bulk metal forming(SBMF)is a promising process for manufacturing complex sheet components with functional elements.In this study,the entire forming process for a typical thin-walled component with external gearing is investigated,including sheet forming and bulk forming processes.Deep drawn cups are prepared during sheet forming;subsequently,upsetting is performed on the sidewall to form external gearing.The upsetting method performed is known as upsetting with a controllable deformation zone(U-CDZ).Compared with the conventional upsetting method,a floating counter punch with a counter force is used in the U-CDZ method such that the forming mechanism is changed into the accumulation of the deformation zone instead of deformation throughout the entire sidewall.The effects of the counter force and material flow are investigated to understand the mechanism.The forming quality,i.e.,the formfilling and effective strain distribution,improved,whereas a high forming load is avoided.In addition,a punch with a lock bead is used to prevent folding at the inner corner during the experiment.展开更多
Thin-walled structures have been widely used in the aerospace industry.The dynamic interaction between the milling cutter and thin-walled workpiece can easily lead to vibration.This paper investigates the vibration ca...Thin-walled structures have been widely used in the aerospace industry.The dynamic interaction between the milling cutter and thin-walled workpiece can easily lead to vibration.This paper investigates the vibration caused during milling the thin-walled workpiece on the NC machining center,presents a theoretical milling vibration model of thin-walled beam.The model was verified by using milling experiments and numerical simulations.Some valuable conclusions are derived,this will be references to scientific research and guides to the vibration-free milling of thin-walled structures at different cutting speeds.展开更多
The spinning technique has been widely used in the manufacture of aerospace thin-walled axisymmetric components because of its excellent formability. Damage and fracture,as the important defects that often occur and m...The spinning technique has been widely used in the manufacture of aerospace thin-walled axisymmetric components because of its excellent formability. Damage and fracture,as the important defects that often occur and must be avoided in the forming and service stages of components,have attracted much attention of researchers. In this paper,the fracture behavior and laws of spinning components such as conical parts,tubular parts,and components with inner ribs are summarized,the typical coupled and uncoupled ductile fracture models are introduced,and their applications in spinning are analyzed. Meanwhile,the recent developments on the modified ductile fracture model in analyzing damage and fracture mechanisms of spinning are emphatically introduced. The results could provide guidance for the selection and establishment of appropriate ductile fracture models in the finite element simulation for the accurate prediction and analysis of fracture moment,location,form,damage mechanism,and evolution law,and help the development of precision spinning techniques for high-performance thin-walled complex components.展开更多
3D printing is a rapid prototyping technology to shape materials or objects through printing layer by layer driven by digital models, which can be adopted for the manufacture of refractory precast components. Thus, th...3D printing is a rapid prototyping technology to shape materials or objects through printing layer by layer driven by digital models, which can be adopted for the manufacture of refractory precast components. Thus, the production technology of refractory precast components as well as the technique and advantages of 3D printing was introduced. The feasibility and application prospect of 3D printing concrete, contour crafting and adhesive 3D printing in refractory precast components were presented.展开更多
Presently,the service performance of new-generation high-tech equipment is directly affected by the manufacturing quality of complex thin-walled components.A high-efficiency and quality manufacturing of these complex ...Presently,the service performance of new-generation high-tech equipment is directly affected by the manufacturing quality of complex thin-walled components.A high-efficiency and quality manufacturing of these complex thin-walled components creates a bottleneck that needs to be solved urgently in machinery manufacturing.To address this problem,the collaborative manufacturing of structure shape and surface integrity has emerged as a new process that can shorten processing cycles,improve machining qualities,and reduce costs.This paper summarises the research status on the material removal mechanism,precision control of structure shape,machined surface integrity control and intelligent process control technology of complex thin-walled components.Numerous solutions and technical approaches are then put forward to solve the critical problems in the high-performance manufacturing of complex thin-wall components.The development status,challenge and tendency of collaborative manufacturing technologies in the high-efficiency and quality manufacturing of complex thin-wall components is also discussed.展开更多
装配式建筑设计、生产过程存在标准化程度低、数据联系较差等诸多问题。引入了制造业中面向制造与装配的设计(design for manufacturing and assembly,DFMA)的产品设计理念,研究了装配式建筑竖向预制混凝土(precast concrete,PC)构件的...装配式建筑设计、生产过程存在标准化程度低、数据联系较差等诸多问题。引入了制造业中面向制造与装配的设计(design for manufacturing and assembly,DFMA)的产品设计理念,研究了装配式建筑竖向预制混凝土(precast concrete,PC)构件的快速建模与深化设计应用,通过对建筑企业大量装配式建筑项目PC构件深化设计图纸的梳理分析,分析了图纸中构件组成规律,创新性地将PC构件二次拆分为模块。分析模块的种类、组合规律、数据架构等,形成模块的设计标准。将设计标准融入建筑信息模型(building information modeling,BIM)软件中,并开发相应的工具软件实现模块的快速建模。以软件创建的参数化标准模块为基础,以关联、匹配、调取、组合、拆解的关键技术实现PC构件的深化设计与工厂的制造联系。最后,通过实际工程案例进行测试对比。结果表明,竖向PC构件的建模速度提升70%、深化设计效率提升约80%,深化设计费用节省约80%,实现最小制造成本。研究结果有助于构建装配式建筑标准化的设计和生产体系,推广少规格多组合的设计方法,强化数据联系,提高装配式建筑的综合效益。展开更多
基金The authors are grateful for the support by National Key Research and Development Program of China(2021YFF0500300,2020YFB1708300)the National Natural Science Foundation of China(52205280,12172041).
文摘Lightweight thin-walled structures with lattice infill are widely desired in satellite for their high stiffness-to-weight ratio and superior buckling strength resulting fromthe sandwich effect.Such structures can be fabricated bymetallic additive manufacturing technique,such as selective laser melting(SLM).However,the maximum dimensions of actual structures are usually in a sub-meter scale,which results in restrictions on their appliance in aerospace and other fields.In this work,a meter-scale thin-walled structure with lattice infill is designed for the fuel tank supporting component of the satellite by integrating a self-supporting lattice into the thickness optimization of the thin-wall.The designed structure is fabricated by SLM of AlSi10Mg and cold metal transfer welding technique.Quasi-static mechanical tests and vibration tests are both conducted to verify the mechanical strength of the designed large-scale lattice thin-walled structure.The experimental results indicate that themeter-scale thin-walled structure with lattice infill could meet the dimension and lightweight requirements of most spacecrafts.
文摘To investigate the vibration principle in machining thin-walled components, a dynamic model for end milling of flexible structures is built based on considering the variations in the dynamic chip thickness and the differences between up-milling and down-milling. Two milling experiments verify the model. Experimental results show that the model can predict the milling force and displacements simultaneously in the dynamic milling process.
基金supported by the National Science Fund for Distinguished Young Scholars(50525516)the National Natural Science Foundation of China(U1637209,51175111,50375036,and 59975021).
文摘A new generation of fluid pressure forming technology has been developed for the three typical structures of tubes,sheets,and shells,and hard-to-deform material components that are urgently needed for aerospace,aircraft,automobile,and high-speed train industries.in this paper,an over all review is introduced on the state of the art in fundamentals and processes for lower-pressure hydroforming of tubular components,double-sided pressure hydroforming of sheet components,die-less hydroforming of ellipsoidai shells,and dual hardening hot medium forming af hard-to-deform materiais Particular attention is paid to deformation behavior,stress state adjustment,defect prevention,and typical applications.In addition,future development directions of fluid pressure forming technology are discussed,including hyper lower-loading forming for ultra-large non-uniform components,precision for ming for intermetallic compound and high-entropy alloy components,intelligent process and equipment,and precise finite element simulation of inhomogeneous and strong anisotropic thin shells.
基金supported by the National Natural Science Foundation of China(No.51375396)the Shaanxi Science and Technology Innovation Project Plan,China(No.2016KTCQ01-50)
文摘Fixture locating layout has a direct and influential impact on aeronautical thin-walled component(ATWC)manufacturing quality.The purpose is to develop a topological optimization method for ATWC fixture locating layout to minimize the manufacturing deformation.Firstly,a topological optimization model that takes the stiffness of ATWC as the objective function and the volume of the locating structure as the constraint is established.Secondly,ATWC and the locating structure are regarded as an integrated entity,and the variable-density method based topological optimization approach is adopted for the optimization of the locating structure using ABAQUS topology optimization module(ATOM).Thirdly,through a subsequent model reconstruction referring to the obtained topological structure,the optimal fixture locating layout is achieved.Finally,a case study is conducted to verify the proposed method and the comparison results with firefly algorithm(FA)coupled with finite element analysis(FEA)indicate that the number and positions of the locators for ATWC can be optimized simultaneously and successfully by the proposed topological optimization model.
基金This work was financially supported by the Program of National Natural Science Foundation of China(Nos.U1937204 and 51905124)China Postdoctoral Science Foundation(2019M661278).
文摘Complex thin-walled titanium alloy components play a key role in the aircraft,aerospace and marine industries,offering the advantages of reduced weight and increased thermal resistance.The geometrical complexity,dimensional accuracy and in-service properties are essential to fulfill the high-performance standards required in new transportation systems,which brings new challenges to titanium alloy forming technologies.Traditional forming processes,such as superplastic forming or hot pressing,cannot meet all demands of modern applications due to their limited properties,low productivity and high cost.This has encouraged industry and research groups to develop novel high-efficiency forming processes.Hot gas pressure forming and hot stamping-quenching technologies have been developed for the manufacture of tubular and panel components,and are believed to be the cut-edge processes guaranteeing dimensional accuracy,microstructure and mechanical properties.This article intends to provide a critical review of high-efficiency titanium alloy forming processes,concentrating on latest investigations of controlling dimensional accuracy,microstructure and properties.The advantages and limitations of individual forming process are comprehensively analyzed,through which,future research trends of high-efficiency forming are identified including trends in process integration,processing window design,full cycle and multi-objective optimization.This review aims to provide a guide for researchers and process designers on the manufacture of thin-walled titanium alloy components whilst achieving high dimensional accuracy and satisfying performance properties with high efficiency and low cost.
基金Supported by National Natural Science Foundation of China(Grant Nos.51875351,51475296).
文摘Sheet-bulk metal forming(SBMF)is a promising process for manufacturing complex sheet components with functional elements.In this study,the entire forming process for a typical thin-walled component with external gearing is investigated,including sheet forming and bulk forming processes.Deep drawn cups are prepared during sheet forming;subsequently,upsetting is performed on the sidewall to form external gearing.The upsetting method performed is known as upsetting with a controllable deformation zone(U-CDZ).Compared with the conventional upsetting method,a floating counter punch with a counter force is used in the U-CDZ method such that the forming mechanism is changed into the accumulation of the deformation zone instead of deformation throughout the entire sidewall.The effects of the counter force and material flow are investigated to understand the mechanism.The forming quality,i.e.,the formfilling and effective strain distribution,improved,whereas a high forming load is avoided.In addition,a punch with a lock bead is used to prevent folding at the inner corner during the experiment.
文摘Thin-walled structures have been widely used in the aerospace industry.The dynamic interaction between the milling cutter and thin-walled workpiece can easily lead to vibration.This paper investigates the vibration caused during milling the thin-walled workpiece on the NC machining center,presents a theoretical milling vibration model of thin-walled beam.The model was verified by using milling experiments and numerical simulations.Some valuable conclusions are derived,this will be references to scientific research and guides to the vibration-free milling of thin-walled structures at different cutting speeds.
基金National Science and Technology Major Project(J2019-VII-0014-0154)the Key Project of National Natural Science Foundation of China(No.52130507)+1 种基金National Natural Science Foundation of China(No.51790175)National Key R&D Program of China(Nos.2020YFA0711100 and 2021YFB3400900)。
文摘The spinning technique has been widely used in the manufacture of aerospace thin-walled axisymmetric components because of its excellent formability. Damage and fracture,as the important defects that often occur and must be avoided in the forming and service stages of components,have attracted much attention of researchers. In this paper,the fracture behavior and laws of spinning components such as conical parts,tubular parts,and components with inner ribs are summarized,the typical coupled and uncoupled ductile fracture models are introduced,and their applications in spinning are analyzed. Meanwhile,the recent developments on the modified ductile fracture model in analyzing damage and fracture mechanisms of spinning are emphatically introduced. The results could provide guidance for the selection and establishment of appropriate ductile fracture models in the finite element simulation for the accurate prediction and analysis of fracture moment,location,form,damage mechanism,and evolution law,and help the development of precision spinning techniques for high-performance thin-walled complex components.
文摘3D printing is a rapid prototyping technology to shape materials or objects through printing layer by layer driven by digital models, which can be adopted for the manufacture of refractory precast components. Thus, the production technology of refractory precast components as well as the technique and advantages of 3D printing was introduced. The feasibility and application prospect of 3D printing concrete, contour crafting and adhesive 3D printing in refractory precast components were presented.
基金supported by the National Natural Science Foundation of China(Nos.51921003,92160301,52175415 and 52205475)the Science Center for Gas Turbine Project(No.P2022-A-IV-002-001)Natural Science Foundation of Jiangsu Province(No.BK20210295).
文摘Presently,the service performance of new-generation high-tech equipment is directly affected by the manufacturing quality of complex thin-walled components.A high-efficiency and quality manufacturing of these complex thin-walled components creates a bottleneck that needs to be solved urgently in machinery manufacturing.To address this problem,the collaborative manufacturing of structure shape and surface integrity has emerged as a new process that can shorten processing cycles,improve machining qualities,and reduce costs.This paper summarises the research status on the material removal mechanism,precision control of structure shape,machined surface integrity control and intelligent process control technology of complex thin-walled components.Numerous solutions and technical approaches are then put forward to solve the critical problems in the high-performance manufacturing of complex thin-wall components.The development status,challenge and tendency of collaborative manufacturing technologies in the high-efficiency and quality manufacturing of complex thin-wall components is also discussed.
文摘装配式建筑设计、生产过程存在标准化程度低、数据联系较差等诸多问题。引入了制造业中面向制造与装配的设计(design for manufacturing and assembly,DFMA)的产品设计理念,研究了装配式建筑竖向预制混凝土(precast concrete,PC)构件的快速建模与深化设计应用,通过对建筑企业大量装配式建筑项目PC构件深化设计图纸的梳理分析,分析了图纸中构件组成规律,创新性地将PC构件二次拆分为模块。分析模块的种类、组合规律、数据架构等,形成模块的设计标准。将设计标准融入建筑信息模型(building information modeling,BIM)软件中,并开发相应的工具软件实现模块的快速建模。以软件创建的参数化标准模块为基础,以关联、匹配、调取、组合、拆解的关键技术实现PC构件的深化设计与工厂的制造联系。最后,通过实际工程案例进行测试对比。结果表明,竖向PC构件的建模速度提升70%、深化设计效率提升约80%,深化设计费用节省约80%,实现最小制造成本。研究结果有助于构建装配式建筑标准化的设计和生产体系,推广少规格多组合的设计方法,强化数据联系,提高装配式建筑的综合效益。
