Evaluation of chilled casting and extrusion-shear forming technology based on numerical simulation and experiments

2021 ◽  
Vol 63 (8) ◽  
pp. 728-735
Author(s):  
H. J. Hu ◽  
S. L. Gan ◽  
Y. Tian ◽  
D. F. Zhang ◽  
J. K. Feng ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Three Dimensional ◽  
Hot Extrusion ◽  
Casting Process ◽  
Process Technology ◽  
The Third ◽  
Lateral Extrusion ◽  
Forming Technology ◽  
Deformation Behaviors ◽  
Simulation Results

Abstract Magnesium alloys on the surface of billets might be refined by chilled casting process, but the grains of the center of billets are coarse, and there are a lot of void defects in the center of billets. These defects can be eliminated by hot extrusion, while fibrous microstructures and strong basal textures might be formed. This paper presents a new short process technology which includes chilled casting and extrusion-shear (CCES). It is crucial to understand the effects of die structures on the deformation behaviors, strain distribution and load requirements. Three selections of processes and die structures were done by simulations and experiments which include CCES process with 4 times consecutive shearings plastic deformation, CCES process by lateral extrusion with 90° shearing angle, and combined CCES process mode. The research results show the third selection is recommended. Three-dimensional (3D) geometric models with different channel angles (30°, 45°) for the third selection CCES dies were designed. The heterogeneities of plastic deformation by CCES dies with different channel angles were analyzed from the simulation results. The simulation results show strains decrease with rising of channel angles. The lower channel angles improve the deformation heterogeneity of magnesium alloy billets. Smaller channel angles obtain higher strains and produce tinier sub-grains. The forces of the CCES process decrease with rising of channel angles. The analysis results showed that finer and uniform microstructures can be obtained if channel angles in the CCES dies are appropriate.

Study on Precision Forging Schemes of Hypoid Driving Gear

2012 ◽  
Vol 472-475 ◽  
pp. 692-695
Author(s):  
Jian Hua Wang ◽  
Fu Xiao Chen
Keyword(s):  
Equivalent Stress ◽  
Three Dimensional ◽  
Equivalent Strain ◽  
Precision Forging ◽  
Forming Technology ◽  
Blank Shape ◽  
Simulation Results ◽  
Three Dimensional Models ◽  
3D Software ◽  
Deform 3D

By analyzing the characteristics and forming technology of hypoid driving gear, it was suitable for adopting fully enclosed die forging principle to form the gear. Based on different forging methods, three kinds of blank shape and corresponding forming schemes were designed. The three dimensional models of blank and die were created by the UG software. The three forming schemes were simulated by the Deform-3D software. The simulation results of distribution of equivalent stress, distribution of equivalent strain and load-stroke curve were comparatively analyzed. Then the most reasonable scheme was chosen. At last, the rationality of numerical simulation can be further verified by the optimized scheme was proved by experiment.

Numerical Simulation on Spiral Hot Bending Process for End Sheet of Tubular Pile

2012 ◽  
Vol 562-564 ◽  
pp. 1373-1376
Author(s):  
Shi Min Xu ◽  
Hua Gui Huang ◽  
Deng Yue Sun
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Radial Direction ◽  
Three Dimensional ◽  
Element Model ◽  
Manufacturing Method ◽  
Forming Technology ◽  
Bending Process ◽  
Simulation Results ◽  
The Moment

A new manufacturing method of spiral hot bending process for the end sheet of tubular pile was introduced in this paper. A three-dimensional (3-D) thermal-mechanical coupled elastic-plasticity finite element model was setup to simulate the hot bending process, and then, the section deformation mechanism from hot bar by rolling to the end sheet has been investigated from the simulation results. The industry manufacture conditions show that the efficiency and quality has been highly improved by the spiral hot bending process. The thickness variety along the radial direction of the workpiece has also been analyzed, the moment and force during the hot bending was also presented in this paper. These conclusions obtained can guide for the forming technology making for both the end sheet of tubular pile and other ring parts.

Mechanical Behavior of the Long Rod Penetrator during Launch

2004 ◽  
Vol 261-263 ◽  
pp. 1629-1634
Author(s):  
J.B. Kim
Keyword(s):  
Numerical Simulation ◽  
Dynamic Stress ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
The Third ◽  
Rod System ◽  
Long Rod ◽  
Dynamic Stress Analysis ◽  
Simulation Results ◽  
Von Mises

This study presents a three-dimensional dynamic stress analysis of the sabot/rod system during launch. A study was undertaken to investigate the influence of forward sabot diameter and rod length on the stress of projectile rod traveling in the gun tube. Three types of gun tube profile were simulated. The first profile is straight. The second profile of the tube droop is caused only by gravity and the third is combined droop profile which is caused by gravity with the manufacture status. Numerical simulation results showed that the maximum von Mises stress due to in-bore behavior of the sabot/rod system could be decreased by changing the forward sabot diameter in a tube drooped by gravity loads with the manufacture status. The results also showed that the stress of rod was affected by the factor of at·L/D· ( at ; combined acceleration, L ; length of rod, D ; diameter of rod), and it becomes minimum when the aspect ratio L/D becomes 14 in the model used in the study. in the study

scholarly journals COLD PLASTIC DEFORMATION OF PROCESSES IN CONDITIONS OF BORDER FORMATION

2021 ◽  
pp. 15-22
Author(s):  
Vasyl Muzychuk
Keyword(s):  
Plastic Deformation ◽  
Stress Tensor ◽  
Three Dimensional ◽  
Point Of View ◽  
Cold Plastic Deformation ◽  
The Third ◽  
Third Invariant ◽  
History Of ◽  
Margin Of Safety ◽  
Comprehensive Study

The article considers the process of forming the inner slot profile on a pipe billet by the method of cold plastic deformation, by compressing them with a matrix on a profile slotted mandrel (by the method of "covering" drawing). A comprehensive study of the mechanics of shaping products to assess their quality and study the possibility of improving the process itself. In the case of three-dimensional molding, the surface of plasticity depends on the history of deformation, which is determined by the change in the stress state with increasing accumulated intensity of deformation. The surface of plasticity in this case is not fixed and can be constructed using the criterion of deformability, which provides the position of the point of the fracture surface, taking into account the history of deformation. The planes of deformation and boundary surfaces of plasticity are constructed, which showed a sufficient margin of plasticity for the process of forming the inner splined profile. It is substantiated that when constructing the load trajectory in the space of dimensionless indicators and its type is unambiguously determined by the conditions of formation characteristic of the studied process and practically does not depend on the mechanical properties of the deformed metal. The areas of deformation closest to the failure are determined by indicators that take into account the influence of the first and third invariants of the stress tensor (lateral region and area of depressions of the profile relative to the process of forming the internal splined profile), in which the used plasticity reaches values = 0,34 ... 0,4. From the point of view of providing a margin of safety, such calculations must be performed taking into account the indicator that takes into account the influence of the third invariant of the stress tensor.

scholarly journals NUMERICAL INVESTIGATION OF THE INFLUENCE OF PUNCH TIP RADIUS AND INTERPOLATOR TYPE IN MULTI-POINT FORMING

2019 ◽  
Vol 19 (2) ◽  
pp. 114-128
Author(s):  
Abdul Kareem J Kadhim ◽  
Ragad A Neama
Keyword(s):  
Three Dimensional ◽  
Thickness Variation ◽  
Work Piece ◽  
Finite Element Code ◽  
B Spline ◽  
Forming Technology ◽  
Different Shapes ◽  
Simulation Results ◽  
Tip Radius ◽  
Reconfigurable Die

Multi-point forming (MPF) is a new flexible forming technology in which the fixed shape of conventional dies is replaced by a pair of opposed matrices of movable punch elements called "punch group".By using multi-point die a variety of three dimensional sheet parts of different shapes can be produced. However due to the discrete contacts between the work piece and punches the dimple defects occurred. In this paper, B-spline technique was used to represent the profile of the final product shape by adjusting the punch height of reconfigurable die. Finite element code (ANSYS 11) was used to simulate the MPF process and to investigate the influence of punch tip radius the interpolator type on the stress distribution, thickness variation and dimpling defect .The simulation results show that the large tip radius and (4mm) rubber interpolator have a great effect in reducing the stress concentration, thickness variation and also prevent the dimpling defect.

scholarly journals Development of Software for the Simulation of Rolling Steel Under the Coexistence of Liquid and Solid State / Rozwój Oprogramowania Do Symulacji Walcowania Stali W Warunkach Współistnienia Fazy Ciekłej I Stałej

2015 ◽  
Vol 60 (4) ◽  
pp. 2783-2790
Author(s):  
D. Jędrzejczyk ◽  
M. Hojny ◽  
M. Głowacki
Keyword(s):  
Plastic Deformation ◽  
Continuous Casting ◽  
Mathematical Models ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Casting Process ◽  
Density Variation ◽  
Rolled Strip ◽  
Final Phase ◽  
Three Dimensional Model

The paper presents the results of the application simulating the rolling process of steel in terms of coexistence of liquid and solid phases. The created mathematical models can be the basis for creation of systems that simulate the final phase of the continuous casting process relying on using a roller burnishing machine for continuous casting of steel. For a complete description of the performance of the material during deformation in these conditions, the constructed mathematical model is a fully three-dimensional model and consists of three parts: thermal, mechanical, and density variation submodels. The thermal model allows the prediction of temperature changes during plastic deformation of solidifying material. The mechanical model determines the kinetics of plastic continuum flow in the solid and semi-solid states, and the resulting deformation field. The temperature of the process forces supplementing the description of the performance of the material with a density variation model that allows the prediction of changes in the density of the material during the final phase of solidification with simultaneous plastic deformation. For the purpose built model, experimental studies were performed using a physical simulator Gleeble 3800®. They allowed the determination of the necessary physical properties of the metal within the temperature of change state. In addition to presenting the developed models the work also includes the description of the author’s application that uses the above mathematical models. The application was written in the fully object-oriented language C++ and is based on the finite element method. The developed application beside the module data input, also consist of a module of three-dimensional visualization of the calculations results. Thanks to it, the analysis of the distribution of the particular rolling parameters in any cross-section of the rolled strip will be possible. The paper presents the results of the authors’ research in the area of the advanced computer simulation.

The orbit of Pluto over a long interval of time

1966 ◽  
Vol 25 ◽  
pp. 227-229 ◽  
Author(s):  
D. Brouwer
Keyword(s):  
Periodic Orbit ◽  
Numerical Integration ◽  
Restricted Problem ◽  
Three Dimensional ◽  
The Third ◽  
Circular Restricted Problem ◽  
Resonance Relation

The paper presents a summary of the results obtained by C. J. Cohen and E. C. Hubbard, who established by numerical integration that a resonance relation exists between the orbits of Neptune and Pluto. The problem may be explored further by approximating the motion of Pluto by that of a particle with negligible mass in the three-dimensional (circular) restricted problem. The mass of Pluto and the eccentricity of Neptune's orbit are ignored in this approximation. Significant features of the problem appear to be the presence of two critical arguments and the possibility that the orbit may be related to a periodic orbit of the third kind.

Construction of plastic contact deformation maps on ceramics: a case study on aluminum nitride

1996 ◽  
Vol 54 ◽  
pp. 636-637
Author(s):  
D. L. Callahan
Keyword(s):  
Plastic Deformation ◽  
Aluminum Nitride ◽  
Mechanical Response ◽  
Three Dimensional ◽  
Bright Field Image ◽  
Perfectly Plastic ◽  
Contrast Analysis ◽  
Deformation Patterns

Modern polishing, precision machining and microindentation techniques allow the processing and mechanical characterization of ceramics at nanometric scales and within entirely plastic deformation regimes. The mechanical response of most ceramics to such highly constrained contact is not predictable from macroscopic properties and the microstructural deformation patterns have proven difficult to characterize by the application of any individual technique. In this study, TEM techniques of contrast analysis and CBED are combined with stereographic analysis to construct a three-dimensional microstructure deformation map of the surface of a perfectly plastic microindentation on macroscopically brittle aluminum nitride.The bright field image in Figure 1 shows a lg Vickers microindentation contained within a single AlN grain far from any boundaries. High densities of dislocations are evident, particularly near facet edges but are not individually resolvable. The prominent bend contours also indicate the severity of plastic deformation. Figure 2 is a selected area diffraction pattern covering the entire indentation area.

Sign in / Sign up

Export Citation Format

Share Document