In this investigation,a new silicone rubber-based MRE material was prepared to be used as a forming medium in manufacturing thin-walled complexshaped Ni-based tubes through the bulging process.Thus,it is significant ...In this investigation,a new silicone rubber-based MRE material was prepared to be used as a forming medium in manufacturing thin-walled complexshaped Ni-based tubes through the bulging process.Thus,it is significant to investigate the effect of magnetic field intensity,magnetic field loading time,and angle on the mechanical properties of the prepared MRE material during the curing process.The obtained results showed that increasing the magnetic field intensity during the curing process can improve the orientation of the chain structure in the elastomer matrix effectively.However,its mechanical properties are the best under the corresponding magnetic field intensity of 321 mT.Besides,by extending the magnetic field loading time in the curing process,the orientation of the chain structure was optimized,at the same time,the mechanical properties were also improved,and the best loading time is about 20–25 min.By changing the loading angle of the magnetic field during the curing process,the mechanical properties of the MRE were improved.When the loading angle of the magnetic field is 90°,the elastomer showed the best compression mechanical properties and excellent compression reversibility.Besides,for the anisotropic MRE material,the performance with magnetic compression is always better than that without magnetic compression.展开更多
In three and six-axis free-bending equipment,the deformation zone length(A)is a fixed mechanical structure parameter modified when the relevant structure is redesigned and manufactured.In this study,a six degree of fr...In three and six-axis free-bending equipment,the deformation zone length(A)is a fixed mechanical structure parameter modified when the relevant structure is redesigned and manufactured.In this study,a six degree of freedom(6-DOF)parallel mechanism was used as the control mechanism of the bending die,and a new method of changing the deformation zone length(A)was proposed.Firstly,an idealized geometric model of free bending-based active motion was established.Then,the influence of the deformation zone length(A)on the bending moment and the bending radius of the tube was analyzed.In addition,the finite element simulation and a kinematic model of free bending-based active motion controlled by the 6-DOF parallel mechanism were established,and bending processes of the SS304 tube with different deformation zone lengths were investigated.Afterwards,the impact of the deformation zone length(A)on the bending radius,bending moment,wall thickness,and motion of the parallel mechanism were analyzed.Finally,experiments were carried out on the free-bending equipment based on the 6-DOF parallel mechanism.Experiments verified the rules in the theoretical analysis,finite element simulation,and kinematic simulation.展开更多
3D free bending process,an advanced metal forming technology,has attracted much attention due to its unique geometrical flexibility and efficiency.Filling tubes with materials may effectively reduce the distortion in ...3D free bending process,an advanced metal forming technology,has attracted much attention due to its unique geometrical flexibility and efficiency.Filling tubes with materials may effectively reduce the distortion in the cross-section area and restrain wrinkling and collapse of tube wall.In the present study,the impacts of filling different materials on the copper tubes during 3D free bending process were investigated.We have found that copper tubes filled with low melting point alloys could induce the most uniform stress distribution,which result in better formability and moderate thickness changing rates when compared to SS304 steel balls and PU rubbers.The lowest ellipticity reached to 1.467%.展开更多
In the 3 D free bending forming system,the bending die can be designed either in a sliding type or rolling friction type.Bending die-based sliding friction type is often called normal bending dies;however,the bending ...In the 3 D free bending forming system,the bending die can be designed either in a sliding type or rolling friction type.Bending die-based sliding friction type is often called normal bending dies;however,the bending dies-based rolling friction type includes bending die-based roller type and ball type in structure.In the current study,the impact of three bending dies on the forming force,and the bent tube quality was investigated.The obtained results showed that the tangential stresses and strains of the tubes formed by the bending die-based roller type were the smallest among the three bending dies.Besides,the spherical bearing force PUwas reduced drastically after using the roller type and ball type compared to the sliding friction type.Moreover,the uniformity of the wall thickness distribution of the tubes formed by the roller type and ball type was better than those obtained from the sliding friction type.In addition,the cross-section distortion rate was reduced by 2.8%using the roller type,and 1.8%using ball-type compared to the sliding friction type.展开更多
This study aims at investigating the impact of using the Magnetorheological Elastomers(MREs)medium to improve the formability of T-shaped Inconel 718 tubes during the bulging process.Besides,the influence of the punch...This study aims at investigating the impact of using the Magnetorheological Elastomers(MREs)medium to improve the formability of T-shaped Inconel 718 tubes during the bulging process.Besides,the influence of the punch size and the intensity of the magnetic field on the branch height and wall thickness distribution of the T-shaped Inconel 718 tubes are also explored.The results showed that the parts formed by the punch with a length of 5 mm in the pressurization zone have better forming quality.The external magnetic field can promote a high branch,and by increasing the intensity of the magnetic field,the branch height was increased and then decreased.At the same time,the magnetic field reduced the amount of material accumulation between the guiding zone and the bulging zone.Besides,it promotes the material in the guiding zone to enter the bulging zone and improve the bulging ability of the T-shaped tube.展开更多
基金The funding for the investigation in this paper mainly comes from the following funds.Funded by the National Natural Science Foundation Key Project of China(Grant No.U1937206)the authors are Li,Xu,Guo,the specific grant numbers was RMB 100,000.Funded by the Jiangsu Province Key Research and Development Project(No.BE2019007-2)+2 种基金the authors are Abd,Cheng,the specific grant numbers was RMB 200,000.Funded by the Opening Project of Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology(No.ASMA201903)the authors are Wu,Yang,Hu,the specific grant numbers was RMB 50,000.Funded by the Basic Scientific Research Operations(Approval No.NT2020015)the authors are Shen,Tao,Guo,the specific grant numbers was RMB 100,000.
文摘In this investigation,a new silicone rubber-based MRE material was prepared to be used as a forming medium in manufacturing thin-walled complexshaped Ni-based tubes through the bulging process.Thus,it is significant to investigate the effect of magnetic field intensity,magnetic field loading time,and angle on the mechanical properties of the prepared MRE material during the curing process.The obtained results showed that increasing the magnetic field intensity during the curing process can improve the orientation of the chain structure in the elastomer matrix effectively.However,its mechanical properties are the best under the corresponding magnetic field intensity of 321 mT.Besides,by extending the magnetic field loading time in the curing process,the orientation of the chain structure was optimized,at the same time,the mechanical properties were also improved,and the best loading time is about 20–25 min.By changing the loading angle of the magnetic field during the curing process,the mechanical properties of the MRE were improved.When the loading angle of the magnetic field is 90°,the elastomer showed the best compression mechanical properties and excellent compression reversibility.Besides,for the anisotropic MRE material,the performance with magnetic compression is always better than that without magnetic compression.
基金supported by the National Natural Science Foundation of China(Nos:U1937206,52175328,52105360)the Opening Project of State Key Lab of Digital Manufacturing Equipment&Technology(No.DMETKF2021004)+3 种基金Jiangsu Province Key Research and Development Project(No.BE2019007-2)Fundamental Research Funds for the Central Universities(No.NS2021046)Ningbo"science and technology innovation 2025"major special project(No.2020Z078)Natural Science Foundation of Jiangsu Province(No.BK20200453).
文摘In three and six-axis free-bending equipment,the deformation zone length(A)is a fixed mechanical structure parameter modified when the relevant structure is redesigned and manufactured.In this study,a six degree of freedom(6-DOF)parallel mechanism was used as the control mechanism of the bending die,and a new method of changing the deformation zone length(A)was proposed.Firstly,an idealized geometric model of free bending-based active motion was established.Then,the influence of the deformation zone length(A)on the bending moment and the bending radius of the tube was analyzed.In addition,the finite element simulation and a kinematic model of free bending-based active motion controlled by the 6-DOF parallel mechanism were established,and bending processes of the SS304 tube with different deformation zone lengths were investigated.Afterwards,the impact of the deformation zone length(A)on the bending radius,bending moment,wall thickness,and motion of the parallel mechanism were analyzed.Finally,experiments were carried out on the free-bending equipment based on the 6-DOF parallel mechanism.Experiments verified the rules in the theoretical analysis,finite element simulation,and kinematic simulation.
基金financial support from the Open Research Funds of the Jiangsu Key Laboratory of Nuclear Energy Equipment Materials Engineering of China(No.NJ20170012)the China Aviation Science Foundation(No.2016ZE52047)the Jiangsu Province Science and Technology Program of China(No.BE2016156).
文摘3D free bending process,an advanced metal forming technology,has attracted much attention due to its unique geometrical flexibility and efficiency.Filling tubes with materials may effectively reduce the distortion in the cross-section area and restrain wrinkling and collapse of tube wall.In the present study,the impacts of filling different materials on the copper tubes during 3D free bending process were investigated.We have found that copper tubes filled with low melting point alloys could induce the most uniform stress distribution,which result in better formability and moderate thickness changing rates when compared to SS304 steel balls and PU rubbers.The lowest ellipticity reached to 1.467%.
基金supported from the Jiangsu Province Key Research and Development Project(No.BE2019007-2)Opening Project of Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology of China(No.ASMA201903)National Natural Science Foundation of China(No.U1937206)。
文摘In the 3 D free bending forming system,the bending die can be designed either in a sliding type or rolling friction type.Bending die-based sliding friction type is often called normal bending dies;however,the bending dies-based rolling friction type includes bending die-based roller type and ball type in structure.In the current study,the impact of three bending dies on the forming force,and the bent tube quality was investigated.The obtained results showed that the tangential stresses and strains of the tubes formed by the bending die-based roller type were the smallest among the three bending dies.Besides,the spherical bearing force PUwas reduced drastically after using the roller type and ball type compared to the sliding friction type.Moreover,the uniformity of the wall thickness distribution of the tubes formed by the roller type and ball type was better than those obtained from the sliding friction type.In addition,the cross-section distortion rate was reduced by 2.8%using the roller type,and 1.8%using ball-type compared to the sliding friction type.
基金supported by the Key Program of the National Natural Foundation of China(No.U1937206)Jiangsu Province Key Research and Development Project(No.BE2019007-2)+2 种基金Opening Project of Jiangsu Key Laboratory of Advanced Structural MaterialsApplication Technology(No.ASMA201903)Basic scientific research operating expenses(No.NT2020015).
文摘This study aims at investigating the impact of using the Magnetorheological Elastomers(MREs)medium to improve the formability of T-shaped Inconel 718 tubes during the bulging process.Besides,the influence of the punch size and the intensity of the magnetic field on the branch height and wall thickness distribution of the T-shaped Inconel 718 tubes are also explored.The results showed that the parts formed by the punch with a length of 5 mm in the pressurization zone have better forming quality.The external magnetic field can promote a high branch,and by increasing the intensity of the magnetic field,the branch height was increased and then decreased.At the same time,the magnetic field reduced the amount of material accumulation between the guiding zone and the bulging zone.Besides,it promotes the material in the guiding zone to enter the bulging zone and improve the bulging ability of the T-shaped tube.