14 results on '"Huaqing Ren"'
Search Results
2. Deformation mechanics and failure mode in stretch and shrink flanging by double-sided incremental forming
- Author
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Zixuan Zhang, Jun Chen, Huaqing Ren, Huan Zhang, and Jian Cao
- Subjects
0209 industrial biotechnology ,Materials science ,Flanging ,Computer simulation ,Tension (physics) ,business.industry ,Mechanical Engineering ,02 engineering and technology ,Structural engineering ,Condensed Matter Physics ,020303 mechanical engineering & transports ,020901 industrial engineering & automation ,0203 mechanical engineering ,Mechanics of Materials ,visual_art ,visual_art.visual_art_medium ,Formability ,General Materials Science ,business ,Sheet metal ,Failure mode and effects analysis ,Civil and Structural Engineering - Abstract
Incremental sheet metal flanging is efficient and cost-effective in prototyping and low-volume production. However, how the sheet metal fails and how the overall formability is enhanced during incremental sheet flanging are still not well understood. This study attempts to provide an updated level of understanding for the deformation mechanics in fabricating a clover hole-flange with complex in-plane curvatures by double-sided incremental forming. Compared with traditional flanging methods, higher formability has been achieved for both stretch flanging and shrink flanging on a single part. Additionally, numerical simulation is conducted complementarily to reveal the strain evolution, based on which failure modes and reasons are analyzed. Moreover, DMV (Donell–Mushtari–Vlasov) equations are employed to analytically study the shrink flanging process. The investigations lead to the conclusions that meridional tension has positive effect in improving the formability during shrink flanging, while an adverse effect is found in the formability during stretch flanging.
- Published
- 2018
3. General contact force control algorithm in double-sided incremental forming
- Author
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Jian Cao, Dohyun Leem, Kornel F. Ehmann, Newell Moser, Huaqing Ren, Tiemin Li, and Fuhua Li
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0209 industrial biotechnology ,Control algorithm ,Materials science ,business.industry ,Mechanical Engineering ,02 engineering and technology ,Structural engineering ,021001 nanoscience & nanotechnology ,DSIF ,Industrial and Manufacturing Engineering ,Contact force ,020901 industrial engineering & automation ,Compressive strength ,Robustness (computer science) ,Formability ,0210 nano-technology ,business ,Incremental sheet forming ,Haptic technology - Abstract
The utilization of a supporting tool in Double-Sided Incremental Forming (DSIF) imposes a stabilizing compressive stress through the sheet’s thickness, increasing, thereby, the material’s formability and fatigue life. However, these favorable effects strongly depend on a steady tool-metal contact condition. This work presents a general DSIF control scheme, which augments the conventional position servo-loop with explicit force feedback control. The algorithm is examined for its robustness and effectiveness using complex geometries with varying curvatures and wall angles. The resulting parts have demonstrated enhanced material formability and geometric accuracy.
- Published
- 2018
4. A non-orthogonal material model of woven composites in the preforming process
- Author
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Qiangsheng Zhao, Jeffrey Scott Dahl, Huaqing Ren, Xuming Su, Mansour Mirdamadi, Biao Liang, Jian Cao, Danielle Zeng, and Weizhao Zhang
- Subjects
0209 industrial biotechnology ,Materials science ,Tension (physics) ,business.industry ,Finite element software ,Mechanical Engineering ,Composite number ,Process (computing) ,02 engineering and technology ,Bending ,Structural engineering ,Non orthogonal ,021001 nanoscience & nanotechnology ,Compression (physics) ,Industrial and Manufacturing Engineering ,Shear (sheet metal) ,020901 industrial engineering & automation ,Composite material ,0210 nano-technology ,business - Abstract
Woven composites are considered as a promising material choice for lightweight applications. An improved non-orthogonal material model that can decouple the strong tension and weak shear behavior of the woven composite under large shear deformation is proposed for simulating the preforming of woven composites. The tension, shear and compression moduli in the model are calibrated using the tension, bias-extension and bending experiments, respectively. The interaction between the composite layers is characterized by a sliding test. The newly developed material model is implemented in the commercial finite element software LS-DYNA® and validated by a double dome study.
- Published
- 2017
5. Sustainable Manufacturing With Cyber-Physical Discrete Manufacturing Networks: Overview and Modeling Framework
- Author
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Daniel J. Garcia, Fengqi You, Jian Cao, Huaqing Ren, Kornel F. Ehmann, Mojtaba Mozaffar, and Jorge Correa
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0209 industrial biotechnology ,Discrete manufacturing ,Computer science ,business.industry ,Mechanical Engineering ,Sustainable manufacturing ,Computer programming ,Cyber-physical system ,02 engineering and technology ,Industrial and Manufacturing Engineering ,Manufacturing engineering ,Computer Science Applications ,020901 industrial engineering & automation ,020401 chemical engineering ,Control and Systems Engineering ,Computer software ,Sustainability ,0204 chemical engineering ,business - Abstract
Cyber-physical systems (CPS) enable unprecedented communication between product designers and manufacturers. Effective use of these technologies both enables and requires a new paradigm of methods and models to identify the most profitable and environmentally friendly production plans for a manufacturing network. The operating system for cyber-physical manufacturing (OSCM) and the paired network operations administration and monitoring (NOAM) software are introduced. These technologies guide our development of a mixed integer bilevel programming (BP) model that models the hierarchy between designers and manufacturers as a Stackelberg game while considering multiple objectives for each of them. Designers select and pay manufacturers, while manufacturers decide how to execute the order with the payment provided by the designer. To solve the model, a tailored solution method combining a decomposition-based approach with approximation of the lower level Pareto-optimal solution set is proposed. The model is applied to a case study based on a network of manufacturers in Wisconsin and Illinois. With the proposed model, designers and manufacturers alike can take full advantage of CPS to increase profits and decrease environmental impacts.
- Published
- 2018
6. Effective forming strategy for double-sided incremental forming considering in-plane curvature and tool direction
- Author
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Huan Zhang, Zixuan Zhang, Yi Shi, Jun Chen, Newell Moser, Ebot Ndip-Agbor, Jian Cao, Huaqing Ren, Bin Lu, and Kornel F. Ehmann
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0209 industrial biotechnology ,Work (thermodynamics) ,Engineering ,business.industry ,Mechanical Engineering ,Geometry ,02 engineering and technology ,Structural engineering ,021001 nanoscience & nanotechnology ,Curvature ,Industrial and Manufacturing Engineering ,In plane ,020901 industrial engineering & automation ,Fracture (geology) ,Process control ,Formability ,Development (differential geometry) ,0210 nano-technology ,business ,Incremental sheet forming - Abstract
The success of a toolpath in double-sided incremental forming (DSIF) is strongly related to the specified tool gap. It is hypothesized in this work that maintained contact between tools and the sheet can improve the distribution of sheet thickness and hence, improve material formability and prevent premature fracture. Simulation and experimental studies reveal that thickness prediction models solely dependent on the local wall angle are inadequate for general part geometries. A ‘Shamrock’ geometry is proposed leading to the development of a novel improved thickness correction model that incorporates wall angle, in-plane curvature, and tool direction.
- Published
- 2016
7. Optimization of relative tool position in accumulative double sided incremental forming using finite element analysis and model bias correction
- Author
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Ebot Ndip-Agbor, Zhen Jiang, Wei Chen, Jacob Smith, Z. Cedric Xia, Jian Cao, Huaqing Ren, Jiachen Xu, and Newell Moser
- Subjects
0209 industrial biotechnology ,Engineering ,business.industry ,Process design ,Computational intelligence ,02 engineering and technology ,Deformation (meteorology) ,DSIF ,Sample (graphics) ,Finite element method ,symbols.namesake ,020303 mechanical engineering & transports ,020901 industrial engineering & automation ,0203 mechanical engineering ,Position (vector) ,symbols ,General Materials Science ,business ,Gaussian process ,Algorithm ,Simulation - Abstract
Double-Sided Incremental Forming (DSIF) uses two small, independently moving, hemispherical tools on either side of the sheet to form a desired shape by following a predefined tool path. This study was motivated by the observation that the relative tool position of the tools, specified in the tool path generation algorithm, affects the formed geometric accuracy. A methodology for defining the relative tool positioning in the tool path generation algorithm based on local part geometry is proposed using simplified Finite Element Analysis (FEA) and sample physical experiments combined with Gaussian Process modeling techniques. This approach can take into account the mechanics of deformation in DSIF explicitly and physical compliance of the DSIF machine implicitly. Physical experiments were performed to demonstrate the effectiveness of the proposed framework.
- Published
- 2015
8. Effects of Tool Deflection in Accumulated Double-Sided Incremental Forming Regarding Part Geometry
- Author
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Newell Moser, Zixuan Zhang, Jian Cao, Huaqing Ren, and Kornel F. Ehmann
- Subjects
Materials science ,Deflection (engineering) ,business.industry ,visual_art ,visual_art.visual_art_medium ,Geometry ,Structural engineering ,Sheet metal ,business - Abstract
Incremental forming is a flexible dieless forming process. In incremental forming, the metal sheet is clamped around its periphery. One or multiple generic stylus-type tools move along a predefined toolpath, incrementally deforming the sheet metal into a final, freeform shape. Compared with the traditional sheet metal forming process, the incremental forming process is more flexible, energy efficient and cost effective due to lower capital investment related to tooling. However, maintaining tight geometric tolerances in incremental formed parts can be a challenge. Specifically, undesired global bending is usually induced near the region between the tools and fixture resulting in a compromise in geometric accuracy. To address this issue, Accumulated Double-Sided Incremental Forming (ADSIF) is proposed, which utilizes two tools on both sides of the metal to better achieve localized deformation while simultaneously constraining global bending outside the forming area. Moreover, in ADSIF, the two tools are moving from inward to outward, and thus the tools are always forming virgin material and so as to limit forces on the already-formed part. Thus, ADSIF has a higher potential to achieve the desired geometry. Nevertheless, tool deflection due to machine compliance is still an issue that can have a considerable effect on geometric accuracy. In this work, the effect of tool deflection related to part geometry is studied for the ADSIF process. The nature of using two tools, rather than one, in ADSIF inherently implies that relative tool position is a critical process parameter. It is the region near these two tools where local squeezing and bending of the sheet occurs, the primary modes of deformation found in ADSIF. The change of relative tool positions (i.e., tool gap and relative position angle) are studied in detail by first developing an analytical model. It is concluded that the tool gap will be enlarged under the influence of tool compliance while the relative position angle is less affected. Additionally, a finite element simulation capable of modeling tool deflection is established. The comparison between the simulation results using rigid tools and deformable ones clearly demonstrated the significant influence of tool compliance on part geometry. Lastly, an axisymmetric part with varying wall angles was formed, and it was confirmed that ADSIF demonstrates improved geometry accuracy compared with conventional Double-Sided Incremental Forming.
- Published
- 2016
9. An Efficient and General Finite Element Model for Double-Sided Incremental Forming
- Author
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David Pritchet, Jian Cao, Kornel F. Ehmann, Huaqing Ren, and Newell Moser
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0209 industrial biotechnology ,Engineering ,business.product_category ,business.industry ,Mechanical Engineering ,Simulation modeling ,Shell (structure) ,Process (computing) ,Mechanical engineering ,02 engineering and technology ,Structural engineering ,Mixed finite element method ,DSIF ,Industrial and Manufacturing Engineering ,Finite element method ,Computer Science Applications ,020303 mechanical engineering & transports ,020901 industrial engineering & automation ,0203 mechanical engineering ,Control and Systems Engineering ,Funnel ,business ,Incremental sheet forming - Abstract
Double-sided incremental forming (DSIF) is a subcategory of general incremental sheet forming (ISF), and uses tools above and below a sheet of metal to squeeze and bend the material into freeform geometries. Due to the relatively slow nature of the DSIF process and the necessity to capture through-thickness mechanics, typical finite element simulations require weeks or even months to finish. In this study, an explicit finite element simulation framework was developed in LS-DYNA using fully integrated shell elements in an effort to lower the typical simulation time while still capturing the mechanics of DSIF. The tool speed, mesh size, element type, and amount of mass scaling were each varied in order to achieve a fast simulation with minimal sacrifice regarding accuracy. Using 8 CPUs, the finalized DSIF model simulated a funnel toolpath in just one day. Experimental strains, forces, and overall geometry were used to verify the simulation. While the simulation forces tended to be high, the trends were still well captured by the simulation model. The thickness and in-plane strains were found to be in good agreement with the experiments.
- Published
- 2016
10. An investigation into the mechanics of double-sided incremental forming using finite element methods
- Author
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Newell Moser, Zixuan Zhang, Kornel F. Ehmann, Jian Cao, and Huaqing Ren
- Subjects
Flexibility (engineering) ,Engineering ,business.industry ,Function (mathematics) ,Structural engineering ,DSIF ,Curvature ,Finite element method ,visual_art ,visual_art.visual_art_medium ,business ,Sheet metal ,Contact area ,Necking - Abstract
Double-Sided Incremental Forming (DSIF) is a developing sheet metal manufacturing process that has gained a lot of attention in recent years due to its inherent flexibility, low-overhead cost, and die-less nature. However, it can be challenging to define the tool gap so as to achieve a desired pressure through the sheet thickness since one must first predict sheet thinning. In this investigation, a novel part design is proposed which varies in-plane curvature as a function of depth. A finite element model for DSIF is developed and the strain histories in various regions are extracted. It was concluded that if the supporting tool loses contact with the sheet, localized necking can occur prior to part failure. Additionally, part geometry can have significant effects on the tool contact area which, consequently, affects the evolution of strain.
- Published
- 2016
11. Effects of Tool Positions in Accumulated Double-Sided Incremental Forming on Part Geometry
- Author
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Jian Cao, Zixuan Zhang, Jacob Smith, Ebot Ndip-Agbor, Kornel F. Ehmann, Huaqing Ren, and Newell Moser
- Subjects
Engineering ,Deformation (mechanics) ,business.industry ,Mechanical Engineering ,Work (physics) ,Motion (geometry) ,Geometry ,Rigid body ,Industrial and Manufacturing Engineering ,Computer Science Applications ,Control and Systems Engineering ,Single point ,business ,Constant (mathematics) ,Incremental sheet forming ,Spiral - Abstract
In Accumulated Double-Sided Incremental Forming (ADSIF), two hemispherical tools impart the local deformation to the sheet via their programmed in-plane spiral motion and the depth of the part is achieved via rigid body motion of the already formed part. Unlike Single Point Incremental Forming (SPIF) and Double-Sided Incremental Forming (DSIF), ADSIF does not impose forces on the already-formed part and therefore, has the potential of achieving higher geometric accuracy. A systematic method is proposed in this work to study the influences of the relative tool positions on the local formed shape and the final geometry, which is essentially the accumulation of all previously formed local deformations. Meanwhile, the concepts of the stable angle and the peak angle are introduced to better describe the cross-sectional geometry of a formed part with a constant wall angle at that particular cross-section. It is recommended, while multiple combinations of the relative positions of two forming tools may achieve the same stable angle, that the positioning parameters should be chosen such that the resultant forming force or the wall angle variation between the stable and peak angles is minimized.Copyright © 2015 by ASME
- Published
- 2015
12. A Mixed Double-Sided Incremental Forming Toolpath Strategy for Improved Geometric Accuracy
- Author
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Zixuan Zhang, Jian Cao, Rui Xu, Jacob Smith, Ebot Ndip-Agbor, Z. Cedric Xia, Newell Moser, Huaqing Ren, Rajiv Malhotra, and Kornel F. Ehmann
- Subjects
Engineering drawing ,Engineering ,business.industry ,Mechanical Engineering ,Process (computing) ,Mechanical engineering ,Forming processes ,DSIF ,Industrial and Manufacturing Engineering ,Computer Science Applications ,law.invention ,Design for manufacturability ,Control and Systems Engineering ,law ,visual_art ,Trajectory ,visual_art.visual_art_medium ,Formability ,Sheet metal ,business ,Stereolithography - Abstract
Double-sided incremental forming (DSIF) is a relatively new dieless forming process which uses two hemispherical ended tools, one on each side of the sheet, moving along a predefined trajectory to locally deform a peripherally clamped sheet of metal. DSIF provides greater process flexibility, higher formability, and eliminates the tooling cost when compared to conventional sheet forming processes. While DSIF provides much improved geometric accuracy compared to other incremental forming processes, current toolpath planning strategies suffer from long forming times. A novel mixed double-sided incremental forming (MDSIF) toolpath strategy is proposed in the present study. It simultaneously reduces the total forming time by half while preserving the best currently achievable geometric accuracy. The effect of the forming parameters, i.e., of the incremental depth and of tool positioning on the geometric accuracy of the parts formed with MDSIF was investigated and compared to those formed by traditional DSIF strategies.
- Published
- 2015
13. A Mixed Toolpath Strategy for Improved Geometric Accuracy and Higher Throughput in Double-Sided Incremental Forming
- Author
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Jian Cao, Rajiv Malhotra, Zixuan Zhang, Huaqing Ren, and Rui Xu
- Subjects
Flexibility (engineering) ,Engineering ,business.industry ,Process (computing) ,Formability ,Forming processes ,Mechanical engineering ,business ,Throughput (business) ,Algorithm ,Incremental sheet forming - Abstract
Incremental sheet forming has attracted considerable attention in the recent past due to advantages that include high process flexibility and higher formability as compared to conventional forming processes. However, attaining required geometric accuracy of the formed part is one of the major issues plaguing this process. The Double-Sided Incremental Forming process has emerged as a potential process variant which can preserve the process flexibility while maintaining required geometric accuracy. This paper investigates a mixed toolpath for Double-Sided Incremental Forming which is able to simultaneously achieve good geometric accuracy and higher throughput than is currently possible. The geometries of parts formed using the mixed toolpath strategy are compared to the desired geometry. Furthermore, an examination of the forming forces is used to uncover the reasons for experimentally observed trends. Future work in this area is also discussed.Copyright © 2014 by ASME
- Published
- 2014
14. Springback Reduction by Annealing for Incremental Sheet Forming
- Author
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Zixuan Zhang, Yi Shi, Jian Cao, Huan Zhang, Huaqing Ren, Newell Moser, and Kornel F. Ehmann
- Subjects
Rapid prototyping ,0209 industrial biotechnology ,Engineering ,business.industry ,Annealing (metallurgy) ,Mechanical engineering ,02 engineering and technology ,Structural engineering ,geometric accuracy ,021001 nanoscience & nanotechnology ,Accuracy improvement ,Industrial and Manufacturing Engineering ,Clamping ,Incremental sheet forming ,Low volume ,springback ,020901 industrial engineering & automation ,Artificial Intelligence ,visual_art ,visual_art.visual_art_medium ,annealing ,0210 nano-technology ,Sheet metal ,business - Abstract
Incremental sheet forming (ISF) has gained much attention in the low volume production and rapid prototyping fields due to its inherent flexibility, low-overhead cost, and die-less nature. However, the geometric inaccuracy of the final achievable parts hinders this process from becoming commercially viable. One of the major sources of geometric inaccuracy is springback, which predominately occurs when the formed sheet metal is unloaded by the forming tools and released from the clamps. This paper focuses on the latter case. A practical annealing method that does not rely on complicated setups and geometry-specific compensation algorithms is proposed to reduce the springback that occurs after the unclamping process. Two clamping devices were developed, which have been demonstrated to significantly reduce the amount of springback. The capability of reducing springback by the proposed method and its potential of integrating it with other geometric accuracy improvement methods will enhance the ISF process towards future industrial applications.
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