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Dawei Zhang - One of the best experts on this subject based on the ideXlab platform.
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analysis of forming error during Thread and spline synchronous Rolling process based on motion characteristic
The International Journal of Advanced Manufacturing Technology, 2019Co-Authors: Dawei Zhang, Shengdun ZhaoAbstract:The Thread meshing and the spline/gear meshing are intercoupling during Thread and spline synchronous Rolling (TSSR) process. The subtle difference between different meshing types will lead to profile error of workpiece. Exploring the influence of motion characteristic on the forming error during TSSR process is important for control of pitch error, design of profile compensation of Rolling die, and improvement of Rolling quality. Thus, in this paper, the accumulative pitch error for spline section of workpiece during TSSR process was defined and modeled according to the motion characteristic in the synchronous Rolling process. A quantitative calculating program of the accumulative pitch error has been compiled by using MATLAB code based on the motion models during Thread Rolling process and spline Rolling process. Then, the influences of calculation step, rotating parameter of Rolling die at initial contact state, and initial values for numerical solution of motion models of Thread section on the calculation accuracy were investigated. The influences of processing parameters and geometrical parameters on the accumulative pitch error were studied by means of orthogonal experiment design method.
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determination of friction conditions in cold Rolling process of shaft part by using incremental ring compression test
The International Journal of Advanced Manufacturing Technology, 2017Co-Authors: Dawei Zhang, Minchao Cui, Miao Cao, Ningyu Ben, Shengdun ZhaoAbstract:The incremental ring compression test (IRCT) was developed to investigate the friction condition in cold-Rolling process of spline or Thread shaft. During IRCT process, the upper die is loaded intermittently and new oil film between ring and dies will appear, which can reflect the lubrication characteristic in the spline or Thread Rolling process. The Coulomb friction coefficient and Tresca friction factor were determined by the IRCT, respectively. The magnitude of friction obtained by IRCT presents a notable difference from that obtained by traditional ring compression test. The results provide an accurate friction parameter for studying the cold-Rolling process of shaft part.
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analysis of motion between Rolling die and workpiece in Thread Rolling process with round dies
Mechanism and Machine Theory, 2016Co-Authors: Dawei Zhang, Shengdun ZhaoAbstract:Abstract Exploring the motion characteristics in Thread Rolling process under varied center distance between rotation axes of workpiece and Rolling die is important for accuracy evaluation and process control, and provides a basis for further study on motion compatibility condition in the Thread and spline synchronous Rolling process. The motion characteristics between the die and workpiece under varied center distance in the Thread Rolling process were investigated. Related mathematical models in the Rolling process, such as the rotation angle and the angular velocity for workpiece, the transmission ratio, and the axodes of workpiece and die, were established. The results indicated that: (1) the relationship between rotation angle of workpiece and Rolling time is approximately linearly dependent, transmission ratio almost presents the same change as angular velocity of workpiece; (2) the cross sections of the axodes of workpiece and Rolling die are similar to Archimedes line, where the polar radius reduces with the reduction of center distance; (3) however, the changes of the angular velocity of workpiece, the transmission ratio, and the axodes are closely related to the shape of tooth profile.
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Deformation characteristic of Thread and spline synchronous Rolling process
The International Journal of Advanced Manufacturing Technology, 2016Co-Authors: Dawei Zhang, Shengdun ZhaoAbstract:In the Thread and spline synchronous Rolling (TSSR) process, the Thread Rolling deformation couples with the spline Rolling deformation. The deformation behavior in the synchronous Rolling process is very complex due to multi-die constraint, multi-axes motion, and multi-parameter association. Exploring the deformation characteristics in the TSSR process is important for parameter optimization and process control of the TSSR process. In this paper, the finite element method (FEM) was adopted to investigate the deformation in the TSSR process. The data were extracted from FE code DEFORM and were processed in code MATLAB. The deformation characteristics in the TSSR process were studied by mean of analyzing displacement, strain, and invariants of deviatoric stress tensor. The results in the present study indicated that: direction of rotation of workpiece has an influence on the direction of axial displacement in cores of Threaded section and splined section; the influence of tooth profiles (such as Threaded profile, splined profile) on the TSSR process only presents in the superficial zone; the deformation-affected region along radial direction in the Threaded section is larger than that in the splined section; the deformation in the Threaded section and splined section has little influence on axial regions.
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phase characteristic between dies before Rolling for Thread and spline synchronous Rolling process
The International Journal of Advanced Manufacturing Technology, 2015Co-Authors: Shengdun Zhao, Dawei Zhang, Qi Zhang, Shuqin FanAbstract:The Thread and spline synchronous Rolling process can form the external Threaded and external splined tooth profiles on different parts of component by only one Rolling process. However, it is a coupled Rolling process where the Thread Rolling coupling with the spline Rolling, and both phase adjusting requirements of dies before Rolling for Thread Rolling and spline Rolling should be satisfied in the synchronous Rolling process. Thus, the phase adjustment only by rotating die may be difficult to ensure the Thread and spline Rolling by different dies well connects respectively. In this paper, requirements of phase difference adjustment for dies before Thread Rolling and before spline Rolling have been studied systematically, and the mathematical expressions of phase difference adjustment have been established, and then the requirements of phase difference under different starts of Threaded workpiece and die (or teeth of splined workpiece and die) for two and three Rolling dies before Thread Rolling (or spline Rolling) have been investigated. Based on these, the ratio S of phase difference between corresponding Threaded sections of Rolling dies to that between corresponding splined sections of Rolling dies was introduced, and the phase characteristic between dies and the method of phase difference adjustment under different parameters in Thread and spline synchronous Rolling process were systematically researched. The results indicated that: (1) for Thread (or spline) Rolling process, if the remainder from dividing the starts nw of Thread (or teeth Zw of spline) of workpiece by number N of Rolling dies is equal to the remainder from dividing the starts nd of Thread (or teeth Zd of spline) of Rolling die by N, i.e., nw≡nd(mod N) (or Zw≡Zd(mod N)), then the phases of dies before Rolling are the same, else there is a phase difference between dies; (2) for Thread and spline synchronous Rolling process, if the phase difference of splined section between Rolling die j (j = 2,…, N) and Rolling die 1 is \( {\varphi}_{{\mathrm{s}}_{j1}}=\frac{h}{N}{\theta}_s\left(h=1,\dots, N\right) \) and ratio of phase difference is \( {S}_{j1}=\frac{N}{h}k+1\left(k=0,1,2,3,\dots \right) \), then the die structures of two dies are the same, i.e., the relative phase between Threaded and splined sections for two dies are the same, else the die structures of Rolling dies j and 1 are different and the phase difference for Threaded sections of Rolling dies and the phase difference for splined sections of Rolling dies are assured by die structure itself.
Shengdun Zhao - One of the best experts on this subject based on the ideXlab platform.
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analysis of forming error during Thread and spline synchronous Rolling process based on motion characteristic
The International Journal of Advanced Manufacturing Technology, 2019Co-Authors: Dawei Zhang, Shengdun ZhaoAbstract:The Thread meshing and the spline/gear meshing are intercoupling during Thread and spline synchronous Rolling (TSSR) process. The subtle difference between different meshing types will lead to profile error of workpiece. Exploring the influence of motion characteristic on the forming error during TSSR process is important for control of pitch error, design of profile compensation of Rolling die, and improvement of Rolling quality. Thus, in this paper, the accumulative pitch error for spline section of workpiece during TSSR process was defined and modeled according to the motion characteristic in the synchronous Rolling process. A quantitative calculating program of the accumulative pitch error has been compiled by using MATLAB code based on the motion models during Thread Rolling process and spline Rolling process. Then, the influences of calculation step, rotating parameter of Rolling die at initial contact state, and initial values for numerical solution of motion models of Thread section on the calculation accuracy were investigated. The influences of processing parameters and geometrical parameters on the accumulative pitch error were studied by means of orthogonal experiment design method.
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determination of friction conditions in cold Rolling process of shaft part by using incremental ring compression test
The International Journal of Advanced Manufacturing Technology, 2017Co-Authors: Dawei Zhang, Minchao Cui, Miao Cao, Ningyu Ben, Shengdun ZhaoAbstract:The incremental ring compression test (IRCT) was developed to investigate the friction condition in cold-Rolling process of spline or Thread shaft. During IRCT process, the upper die is loaded intermittently and new oil film between ring and dies will appear, which can reflect the lubrication characteristic in the spline or Thread Rolling process. The Coulomb friction coefficient and Tresca friction factor were determined by the IRCT, respectively. The magnitude of friction obtained by IRCT presents a notable difference from that obtained by traditional ring compression test. The results provide an accurate friction parameter for studying the cold-Rolling process of shaft part.
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analysis of motion between Rolling die and workpiece in Thread Rolling process with round dies
Mechanism and Machine Theory, 2016Co-Authors: Dawei Zhang, Shengdun ZhaoAbstract:Abstract Exploring the motion characteristics in Thread Rolling process under varied center distance between rotation axes of workpiece and Rolling die is important for accuracy evaluation and process control, and provides a basis for further study on motion compatibility condition in the Thread and spline synchronous Rolling process. The motion characteristics between the die and workpiece under varied center distance in the Thread Rolling process were investigated. Related mathematical models in the Rolling process, such as the rotation angle and the angular velocity for workpiece, the transmission ratio, and the axodes of workpiece and die, were established. The results indicated that: (1) the relationship between rotation angle of workpiece and Rolling time is approximately linearly dependent, transmission ratio almost presents the same change as angular velocity of workpiece; (2) the cross sections of the axodes of workpiece and Rolling die are similar to Archimedes line, where the polar radius reduces with the reduction of center distance; (3) however, the changes of the angular velocity of workpiece, the transmission ratio, and the axodes are closely related to the shape of tooth profile.
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Deformation characteristic of Thread and spline synchronous Rolling process
The International Journal of Advanced Manufacturing Technology, 2016Co-Authors: Dawei Zhang, Shengdun ZhaoAbstract:In the Thread and spline synchronous Rolling (TSSR) process, the Thread Rolling deformation couples with the spline Rolling deformation. The deformation behavior in the synchronous Rolling process is very complex due to multi-die constraint, multi-axes motion, and multi-parameter association. Exploring the deformation characteristics in the TSSR process is important for parameter optimization and process control of the TSSR process. In this paper, the finite element method (FEM) was adopted to investigate the deformation in the TSSR process. The data were extracted from FE code DEFORM and were processed in code MATLAB. The deformation characteristics in the TSSR process were studied by mean of analyzing displacement, strain, and invariants of deviatoric stress tensor. The results in the present study indicated that: direction of rotation of workpiece has an influence on the direction of axial displacement in cores of Threaded section and splined section; the influence of tooth profiles (such as Threaded profile, splined profile) on the TSSR process only presents in the superficial zone; the deformation-affected region along radial direction in the Threaded section is larger than that in the splined section; the deformation in the Threaded section and splined section has little influence on axial regions.
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phase characteristic between dies before Rolling for Thread and spline synchronous Rolling process
The International Journal of Advanced Manufacturing Technology, 2015Co-Authors: Shengdun Zhao, Dawei Zhang, Qi Zhang, Shuqin FanAbstract:The Thread and spline synchronous Rolling process can form the external Threaded and external splined tooth profiles on different parts of component by only one Rolling process. However, it is a coupled Rolling process where the Thread Rolling coupling with the spline Rolling, and both phase adjusting requirements of dies before Rolling for Thread Rolling and spline Rolling should be satisfied in the synchronous Rolling process. Thus, the phase adjustment only by rotating die may be difficult to ensure the Thread and spline Rolling by different dies well connects respectively. In this paper, requirements of phase difference adjustment for dies before Thread Rolling and before spline Rolling have been studied systematically, and the mathematical expressions of phase difference adjustment have been established, and then the requirements of phase difference under different starts of Threaded workpiece and die (or teeth of splined workpiece and die) for two and three Rolling dies before Thread Rolling (or spline Rolling) have been investigated. Based on these, the ratio S of phase difference between corresponding Threaded sections of Rolling dies to that between corresponding splined sections of Rolling dies was introduced, and the phase characteristic between dies and the method of phase difference adjustment under different parameters in Thread and spline synchronous Rolling process were systematically researched. The results indicated that: (1) for Thread (or spline) Rolling process, if the remainder from dividing the starts nw of Thread (or teeth Zw of spline) of workpiece by number N of Rolling dies is equal to the remainder from dividing the starts nd of Thread (or teeth Zd of spline) of Rolling die by N, i.e., nw≡nd(mod N) (or Zw≡Zd(mod N)), then the phases of dies before Rolling are the same, else there is a phase difference between dies; (2) for Thread and spline synchronous Rolling process, if the phase difference of splined section between Rolling die j (j = 2,…, N) and Rolling die 1 is \( {\varphi}_{{\mathrm{s}}_{j1}}=\frac{h}{N}{\theta}_s\left(h=1,\dots, N\right) \) and ratio of phase difference is \( {S}_{j1}=\frac{N}{h}k+1\left(k=0,1,2,3,\dots \right) \), then the die structures of two dies are the same, i.e., the relative phase between Threaded and splined sections for two dies are the same, else the die structures of Rolling dies j and 1 are different and the phase difference for Threaded sections of Rolling dies and the phase difference for splined sections of Rolling dies are assured by die structure itself.
Feng Feng - One of the best experts on this subject based on the ideXlab platform.
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Two-dimensional and three-dimensional ®nite element models of external Thread Rolling
2016Co-Authors: Joseph P Domblesky, Feng FengAbstract:Abstract: In the present study, the DEFORM computer code was used to develop two-dimensional and three-dimensional ®nite element models for simulating external Thread Rolling. To simulate Rolling in two dimensions, a plane strain model was used where the Thread is assumed to form through progressive penetration of the blank surface using a parallel set of wedge-shaped indenters. To develop the three-dimensional model, a ¯at-die Rolling process was simulated which incorporated blank rotation, die movement and pitch angle on the die faces. Based on a comparison of Thread form and microhardness with as-rolled Threads, the plane strain model was found to provide a reasonable approximation of Thread-Rolling behaviour. Results obtained from the initial pass of the three-dimensional model are promising although progress is currently limited by the excessive computational time needed, frequency of remeshing and sliding at the die±blank interface
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two dimensional and three dimensional finite element models of external Thread Rolling
Proceedings of the Institution of Mechanical Engineers Part B: Journal of Engineering Manufacture, 2002Co-Authors: Joseph P Domblesky, Feng FengAbstract:AbstractIn the present study, the DEFORM computer code was used to develop two-dimensional and three-dimensional finite element models for simulating external Thread Rolling. To simulate Rolling in two dimensions, a plane strain model was used where the Thread is assumed to form through progressive penetration of the blank surface using a parallel set of wedge-shaped indenters. To develop the three-dimensional model, a flat-die Rolling process was simulated which incorporated blank rotation, die movement and pitch angle on the die faces. Based on a comparison of Thread form and microhardness with as-rolled Threads, the plane strain model was found to provide a reasonable approximation of Thread-Rolling behaviour. Results obtained from the initial pass of the three-dimensional model are promising although progress is currently limited by the excessive computational time needed, frequency of remeshing and sliding at the die-blank interface.
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a parametric study of process parameters in external Thread Rolling
Journal of Materials Processing Technology, 2002Co-Authors: Joseph P Domblesky, Feng FengAbstract:Abstract This paper summarizes the results of a numerical study conducted to analyze the effect of selected process parameters on material flow and Thread profile in external Thread Rolling of large diameter blanks. Based on the previous work where a plane strain model was found to provide a reasonable approximation of the Thread Rolling process, the effect of varying Thread form, friction factor, flow stress, and blank diameter on effective strain and Thread height was analyzed using the finite element code DEFORM. The results of the study show that for the range of conditions considered, that blank diameter had little effect on the as-rolled Thread while flow stress (K and n), friction factor, and Thread form all had significant impact on effective strain at the Thread root and crest and the achievable Thread height. While the rate of work hardening was found to have an effect on the crest profile, the results indicate that it is not the primary factor responsible for seam formation in rolled Threads.
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Numerical Modeling of the External Thread Rolling Process
e-Publications@Marquette, 1999Co-Authors: Feng FengAbstract:External Threaded fasteners manufactured by the Thread Rolling process are applied in many commercial and military applications due to their superior properties. However, the process design for Thread Rolling is still primarily based on empiricism and experience. This approach is very inefficient and expensive. A more scientifically based methodology to predict the process response and product properties prior to Thread Rolling is desired. Numerical simulation and modeling of the Thread Rolling process, based on knowledge of underlying process physics and validated by experimental results, is a powerful tool for optimizing process parameters. At this time, few studies related to numerical simulation of the Thread Rolling process have been published in the literature. In this thesis, a numerically based 2D model for the Thread Rolling process will be established and validated. The relationships between process parameters and effective strain, load and Thread profile obtained from the results of the 2D numerical simulation for the Thread Rolling process will be presented. In addition, a preliminary 3D model for flat-die Thread Rolling will also be presented. The 2D process model and validation results are presented in Chapter 3. The effect of the Thread Rolling process parameters on metal flow, effective strain and Rolling load from the 2D numerical simulation results are discussed in Chapter 4. The 3D modeling of the process is described in Chapter 5. Suggestions for future work and a summary of the results are presented in Chapter 6
W Weronski - One of the best experts on this subject based on the ideXlab platform.
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new method of Thread Rolling
Journal of Materials Processing Technology, 2004Co-Authors: Z Pater, A Gontarz, W WeronskiAbstract:Abstract The research and implementation works completed in the framework of new Thread Rolling technology developed for sleeper fixing screws have been described in the present study. Described Thread Rolling method consists in Thread forming by means of two flat wedges provided with special grooves designed for Thread forming. The results obtained from numerical simulation of Thread Rolling process are presented in the study. The calculations have been completed using finite volumes method (FVM) and finite element method (FEM). Furthermore experimental tests consisting in Thread forming on the bars made of commercial lead in laboratory conditions and results of industrial tests with simultaneous Thread forming on two screws have been described.
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head forging aspects of new forming process of screw spike
Journal of Materials Processing Technology, 2004Co-Authors: A Gontarz, Z Pater, W WeronskiAbstract:Abstract Results of theoretical and experimental research associated with new forming process of screw spikes are presented in this present paper. Actual forming process of screw spikes consists in screw head flash forging and Thread Rolling realised by three rollers. Proposed new process consists of flashless head forging and Thread forming using cross-wedge Rolling process in double configuration. Head forging process simulation using finite volume method (FVM) and finite element method (FEM) of screw spike head forming process and experimental verification for obtained results were carried out. Comparison of forces values and flow kinematics is done. Good agreements of theoretical and experimental results are obtained. Industrial application of new technology is shown, too.
Peter Groche - One of the best experts on this subject based on the ideXlab platform.
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Numerical investigation of the influence of frictional conditions in Thread Rolling operations with flat dies
International Journal of Material Forming, 2018Co-Authors: Peter Groche, Philipp KramerAbstract:Numerical simulation technology has become an important part of the process design stage in bulk metal forming operations. With increasing computing performance, three dimensional simulations within the product design process are thus becoming increasingly feasible. However, the modeling of friction within numerical simulations is still posing a challenge, especially in very friction sensitive processes, such as Rolling of axisymmetric parts. Within the presented work, the process of Rolling with flat dies with consideration of friction (according to Amontons-Coulomb) is simulated and analyzed. With the developed model, tribological loads as well as the influence of friction is investigated. These numerical findings are contrasted with experimental results obtained with an industrial forming machine. It is shown that the numerically obtained results are highly sensitive regarding numerical and physical contact modeling parameters. This is due in part to the highly varying frictional conditions (relative sliding velocity, contact normal stress) within the contact zone. Additionally, it is shown that the contact zone exhibits properties that favor static friction rather than sliding friction. This observation is especially important for an adequate empirical characterization of friction for Thread and profile Rolling processes.
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defect detection in Thread Rolling processes experimental study and numerical investigation of driving parameters
International Journal of Machine Tools & Manufacture, 2018Co-Authors: Philipp Kramer, Peter GrocheAbstract:Abstract Thread Rolling processes are typically used to manufacture Threads in mass production. While these processes are well established, the process design is mostly based on individual experience. Also, the influence of the process configuration, such as maximum output rate and lubrication conditions, towards process limits, has not been studied yet. Thus, due to the lack of process understanding, a systematic design of Thread Rolling processes is not established. Within this paper, a systematic study of the influence of the process configuration and specimen preparation towards the occurrence of defects is performed. In order to enable the investigation of the Rolling process, a sensor setup is introduced that allows to measure forming forces in feed and radial direction in direct force flow. Rolling experiments show that the tribological system influences the Rolling process. An increase of the stroke speed leads to a significant increase of forming force accompanied by the emergence of seams within the root radius for specimens with a zinc-phosphate and polymer coating. Removing this coating prior to the experiments allows to execute trials without force increase nor seams. Accompanying numerical studies are validated with the help of geometrical as well as force measurements and show that these defects are caused by a shift of the relative sliding velocities within the contact zone.