scholarly journals ТЕХНОЛОГІЧНІ АСПЕКТИ ЗАБЕЗПЕЧЕННЯ ЯКОСТІ ДЕТАЛЕЙ ПРИ ПНЕВМОУДАРНОМУ ШТАМПУВАННІ ВИРУБУВАННЯМ-ПРОБИВАННЯМ

2020 ◽  
pp. 137-150
Author(s):  
В. В. Кухар ◽  
Є. А. Фролов ◽  
С. Г. Ясько
Keyword(s):  
Elastic Medium ◽  
Sheet Material ◽  
Experimental Studies ◽  
High Strength ◽  
Technological Capabilities ◽  
Sheet Metal Parts ◽  
Pneumatic Impact ◽  
Cutting Surface ◽  
Similar Character ◽  
Cutting Processes

The paper considers the issues related with technological capabilities and features of the process of cutting-punching of sheet-metal parts with an elastic medium of pneumatic impact stamping, taking into account the indicators of their quality and accuracy, and also suggests effective ways to improve them. One of the promising methods for producing high-precision parts, including those with a complex profile, is a shaping method based on the technology and equipment of pneumatic shock stamping with an elastic medium on the TA-1324 in-stallations. The advantages of this method are environmental cleanliness, safe operation, wide technological capabilities, mobility and versatility, low labour and energy costs. At these installations it is advisable to perform formative operations of separation (cutting-punching) and shallow shaping both as a separate operation and together with cutting-punching. As a workpiece for the study the sheet material of the following grades was used: steel 08kp, aluminium alloy AMG-M, steel 12X18H10T. The thickness varied within the range from 0.5 to 2.5 mm. Dies and copier punches were made of U8A steel, followed by heat treatment to a hardness of HRC 56-62. An analysis of the experimental studies of punching-cutting processes allows us to conclude that with an increase in the number of stamped parts, there is an increase in size deviations from their nominal values. This increase is due to the wear of operating elements (copier punches and dies). At the same time, the sizes of the copier punches are reduced, and the sizes of the matrices are increased. The absolute values of deviations do not depend on the type of operations; their values, both during cutting and punching, are almost the same in each of the samples taken. The process of pneumatic impact stamping, where a hammer with a bevelled end was used, has a similar character. The paper also proposed and tested ways to improve pneumatic impact stamping, providing cutting, punching of parts from sheet copper, aluminium alloys with a thickness of 0.3 to 3 mm and mild steel up to 3 mm thick. The roughness of the cutting surface is in the range Ra = 0.3 to 0.6 μm, and in the case of high-strength materials up to 2.5 mm thick, the roughness of the cutting surface is Ra = 0.6 to 1.0 μm, depending on the contour configuration that is cut down or punched.

Deformation Mechanisms of Ti6Al4V Sheet Material during the Incremental Sheet Forming with Laser Heating

2013 ◽  
Vol 549 ◽  
pp. 372-380 ◽  
Author(s):  
Linda Mosecker ◽  
Alexander Göttmann ◽  
Alireza Saeed-Akbari ◽  
Wolfgang Bleck ◽  
Markus Bambach ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Microstructural Evolution ◽  
Elevated Temperatures ◽  
Sheet Material ◽  
Sheet Thickness ◽  
High Strength ◽  
Local Strain ◽  
Deformation Mechanisms ◽  
Dislocation Glide ◽  
Sheet Metal Parts

ncremental sheet metal forming (ISF) is a suitable process for the production of small batch sizes. Due to the minor tooling effort and low forming forces, ISF enables the production of large components with inexpensive and light machine set-ups. Hence, ISF is an interesting manufacturing technique for aeronautical applications. Sheet metal parts in aircrafts are often made of titanium and its alloys like the high strength alloy Ti Grade5 (Ti6Al4V). The characteristic low formability of Ti6Al4V at room temperature requires forming operations on this material to be carried out at the elevated temperatures. The interaction of heating and deformation cycles results in a microstructure evolution, which is believed to have a high impact on formability and product quality. In the present work, the temperature-dependent microstructural evolution of the as-deformed parts was investigated. Longitudinal pockets with different depths were formed using a laser-assisted ISF process. The microstructural evolution and hardening of the material were analyzed with respect to the local strain in different forming depths and pocket zones. The formability of the material together with the deformation depth and the sheet thickness-reduction were found to be strongly dependent on the applied process temperatures and the activated deformation mechanisms like dislocation glide and dynamic recrystallization.

scholarly journals Experimental and Numerical Investigation on the Perforation Resistance of Double-Layered Metal Shield under High-Velocity Impact of Armor-Piercing Projectiles

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 626
Author(s):  
Riccardo Scazzosi ◽  
Marco Giglio ◽  
Andrea Manes
Keyword(s):  
High Strength Steel ◽  
Steel Plate ◽  
Experimental Studies ◽  
Practical Interest ◽  
High Strength ◽  
Experimental Tests ◽  
Element Model ◽  
Transportation Systems ◽  
Metal Shield ◽  
Softening Parameter

In the case of protection of transportation systems, the optimization of the shield is of practical interest to reduce the weight of such components and thus increase the payload or reduce the fuel consumption. As far as metal shields are concerned, some investigations based on numerical simulations showed that a multi-layered configuration made of layers of different metals could be a promising solution to reduce the weight of the shield. However, only a few experimental studies on this subject are available. The aim of this study is therefore to discuss whether or not a monolithic shield can be substituted by a double-layered configuration manufactured from two different metals and if such a configuration can guarantee the same perforation resistance at a lower weight. In order to answer this question, the performance of a ballistic shield constituted of a layer of high-strength steel and a layer of an aluminum alloy impacted by an armor piercing projectile was investigated in experimental tests. Furthermore, an axisymmetric finite element model was developed. The effect of the strain rate hardening parameter C and the thermal softening parameter m of the Johnson–Cook constitutive model was investigated. The numerical model was used to understand the perforation process and the energy dissipation mechanism inside the target. It was found that if the high-strength steel plate is used as a front layer, the specific ballistic energy increases by 54% with respect to the monolithic high-strength steel plate. On the other hand, the specific ballistic energy decreases if the aluminum plate is used as the front layer.

Numerical Modeling of Tube Hydropiercing Using Phenomenological and Micro-Mechanical Damage Criteria

2013 ◽  
Vol 549 ◽  
pp. 172-179 ◽  
Author(s):  
Amir Hassannejadasl ◽  
Daniel E. Green
Keyword(s):  
Experimental Studies ◽  
Three Dimensional ◽  
Equivalent Plastic Strain ◽  
Mechanical Damage ◽  
High Strength ◽  
Dimensional Finite Element ◽  
Steel Dp600 ◽  
Three Dimensional Finite Element ◽  
Jc Model ◽  
Damage Criteria

Hydropiercing is an efficient way of piercing holes in mass produced hydroformed parts with complex geometries. By driving piercing punches radially into a hydroformed and fully pressurized tube, holes will be pierced and extruded into the tube-wall. Recent experimental studies have shown that the formability of advanced high strength steel (AHSS) tubes can be increased with the application of internal pressure. In this study, three-dimensional finite element simulations of a tube hydropiercing process of a dual phase steel (DP600) were performed in LS-DYNA, using phenomenological, micromechanical and combined damage criteria. Damage was included in the numerical analysis by applying constant equivalent plastic strain (CEPS), the Gurson-Tvergaard-Needleman (GTN), and the Extended GTN (GTN+JC) model. In order to calibrate the parameters in each model, a specialized hole-piercing fixture was designed and piercing tests were carried out on non-pressurized tube specimens. Of the various ductile fracture criteria, the results predicted with the GTN+JC model, such as the punch load-displacement, the roll-over depth, and the quality of the clearance zone correlated the best with the experimental data.

Use of Digital Twins for Mathematical Modeling of Ultrasonic Cutting of Titanium Blanks

2021 ◽  
Vol 1037 ◽  
pp. 369-376
Author(s):  
Maxim Ilyushkin ◽  
Kirill Savelev ◽  
Oleg Krupennikov ◽  
Evgeniy S. Kiselev
Keyword(s):  
Mathematical Modeling ◽  
Thermal Power ◽  
Experimental Studies ◽  
Ultrasonic Field ◽  
Design Parameters ◽  
Digital Twins ◽  
Machine Parts ◽  
Cutting Processes ◽  
Stock Removal ◽  
Processing Zone

The paper presents the results of numerical experimental studies of cutting titanium blanks using mathematical modeling programs, which make it possible to completely repeat technological processes in a computer (digital twin). The LS-DYNA product was used as a program to simulate the process of stock removal from titanium blank. It has been established that the use of this method adequately describes the cutting processes, including with the introduction of the energy of an ultrasonic field into the processing zone, can significantly reduce the duration of experimental research and evaluate the influence of the elements of the cutting mode and design parameters of the tool on the thermal power aspects of the formation of new surfaces of machine parts.

Simulation on the Life Expectancy of Fine Blanking Tool Punch for High-Strength Automobile Start Motor Flange

2014 ◽  
Vol 607 ◽  
pp. 612-615
Author(s):  
Jong Deok Kim ◽  
Hyun Jun Ko
Keyword(s):  
Life Expectancy ◽  
Material Properties ◽  
High Strength ◽  
Manufacturing Cost ◽  
Working Process ◽  
Product Cost ◽  
Fine Blanking ◽  
Stamping Process ◽  
Cutting Surface ◽  
Secondary Operations

Fine blanking is a press-working process that permits the production of precise, finished components which are cleanly sheared through the whole cutting surface. The manufacturing cost can be reduced because the secondary operations such as milling and broaching can be eliminated and the multistage combined stamping process can be added. The product cost can increase, however, while the precise fine blanking tool and high cost fine blanking press are required. Therefore it is important to design the fine blanking tool in view of the life expectancy of the punch. In this paper the fatigue simulation of fine blanking tool punch for automobile start motor flange was conducted using the commercial FEA software ANSYS. Initially, the material properties were tested and the fine blanking tool was designed for production experiments. The modelling of tool elements and the fatigue simulation according to repeated loads were conducted. As a result of fatigue simulation, the fine blanking tool punch for start motor flange had been fractured with 3,981 strokes. In the fine blanking production experiments, the fine blanking tool punch had to be regrinded after it was used with 3,425 strokes. It was also found that the fatigue simulation of fine blanking tool punch was conducted with an error of 14%.

Numerical and Experimental Studies of Residual Stresses in Multipass Welding of High Strength Shipbuilding Steel

2015 ◽  
Vol 59 (3) ◽  
pp. 133-144 ◽  
Author(s):  
Guangming Fu ◽  
Tetyana Gurova ◽  
Marcelo I. Lourenco ◽  
Segen F. Estefen
Keyword(s):  
Residual Stresses ◽  
Experimental Studies ◽  
High Strength ◽  
Shipbuilding Steel ◽  
Multipass Welding

scholarly journals A Novel Force Variation Fine Blanking Process for the High-strength and Low-plasticity Material

2021 ◽  
Author(s):  
Huajie Mao ◽  
Han Chen ◽  
Yanxiong Liu ◽  
Kaisheng Ji
Keyword(s):  
Early Stage ◽  
Hydrostatic Stress ◽  
High Strength ◽  
Forming Force ◽  
Forming Process ◽  
Fine Blanking ◽  
Application Range ◽  
Cutting Surface ◽  
Force Variation ◽  
Blanking Process

Abstract Fine blanking is a kind of metal forming process with the advantages of high precision, good surface quality and low cost. Influenced by the concept of lightweight, a large number of metal materials with high strength are widely used in various fields. High strength materials are prone to be cracked during plastic deformation due to their poor plasticity, which limits the application range of them. This paper proposed a force variation fine blanking process for high-strength and low-plasticity materials. At the same time, a method to find the curve of forming force for this novel process was presented. A 2D finite element fine blanking model was established for the TC4 material. Combining genetic algorithm and neural network methods, a model was built up to find the optimal forming force loading curve. The parts fabricated by force variation loading and constant loading fine blanking process were compared through experiments. The mechanism of force variation fine blanking is also revealed. The forming force mainly affects the length of clean cutting surface by affecting hydrostatic stress. According to the ultimate optimal loading curve, the forming force should be kept at a low level in the early stage of blanking stroke, and increased gradually in the ending stage. In the application of force variation fine blanking, the part with long length of clean cutting surface can be obtained with lower die load.

Ammonia recovery from high strength agro industry effluents

2002 ◽  
Vol 45 (12) ◽  
pp. 189-196 ◽  
Author(s):  
M. Altinbas ◽  
I. Ozturk ◽  
A.F. Aydin
Keyword(s):  
Experimental Studies ◽  
Ammonium Phosphate ◽  
High Strength ◽  
Stoichiometric Ratio ◽  
Ammonia Content ◽  
Magnesium Ammonium Phosphate ◽  
Fenton’S Oxidation ◽  
Ammonia Recovery ◽  
Fenton's Oxidation ◽  
Opium Alkaloid

The aim of the study was to investigate ammonia recovery from high strength agro industry effluents involving significant amounts of ammonia, by applying magnesium ammonium phosphate (MAP) precipitation technology. Two types of industrial effluents have been tested in the study. The first plant was an opium alkaloid processing industry and the second one was a baker`s yeast industry. High chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN) and unacceptable dark brown color characterized effluents from both industries. Effluents from the biologically treated opium alkaloid and baker's yeast industries were both applied at the stoichiometric ratio (Mg:NH4:PO4 =1:1:1) and above the stoichiometric ratio (Mg:NH4:PO4 =1.1:1:1.1) to MAP precipitation. NH4 removals of 61-80% were achieved at the pH of 9.2 at the stoichiometric ratio, whereas 83% NH4 removal was obtained at the pH of 9.2 above the stoichiometric ratio. Experimental studies performed on both anaerobically and/or aerobically treated baker`s yeast and opium alkaloid industry effluents have clearly indicated that MAP precipitation was an appropriate treatment option for NH4 removal or struvite recovery from high ammonia content agro industry effluents. Additional ammonia recovery studies were conducted on ozonated and Fenton's oxidation applied effluents and these have also indicated that the amounts of struvite and the quality of MAP precipitate was increased significantly. In this framework, MAP sludge recovered from combined biological and Fenton's oxidation treatment effluents were considered as a more valuable slow release fertilizer for agricultural use.

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