Thickness Of Sheet Metal Research Articles

Искажение геометрии, окисление кромки, структурные изменения и морфология поверхности реза листового проката толщиной 100 мм из алюминиевых, медных и титановых сплавов при плазменной резке на токе обратной полярности

The introduction describes the feasibility of using reverse polarity plasma cutting to produce large-sized non-ferrous metal blanks up to 100 mm thick. Data on the use of plasma cutting with direct and reverse polarity currents for thick sheet metal and the main technological problems associated with its implementation are presented. The purpose of the work is to study the organization of the structure and properties of the near-surface zone, changes in the chemical and phase composition when cutting aluminum, copper and titanium alloys. The research methods are optical and scanning electron microscopy, microhardness measurement, X-ray diffraction and energy-dispersive analysis. Plasma cutting was carried out using air as a plasma-forming and shielding gas, simultaneously with water injection into the discharge chamber and the formation of a “water fog” around the plasma column. Results and discussion. It is shown that both the arc stability and the shape of the plasma column are of great importance in reverse polarity plasma cutting of rolled sheets. The distortion of the cutting geometry during normal operation is greatest in the central part, and with insufficient heat input it shifts to the lower part and increases significantly. The operation of the plasma torch in air does not lead to significant changes in the composition of the cutting surface of aluminum and copper alloys. A decrease in the magnesium content near the edge is typical for the aluminum alloy in the surface layers. Cutting of the titanium alloy is accompanied by intense oxidation of the surface, especially in areas of difficult metal displacement from the cutting cavity. The formation of titanium oxides, mainly rutile Ti2O, sharply increases the microhardness values in the surface layers, which negatively affects the machinability of the cutting edge and requires shot blasting to remove the oxide layer. The conclusion describes the main patterns of implementing reverse polarity plasma cutting of sheet metal from aluminum, copper and titanium alloys with a thickness of 100 mm.

Investigation of the impact of product thickness and strain on cold forging processes

This study investigates the impact of sheet metal thickness and strain generated on a cold forging process. A cold forging die was manufactured based on a numerically modelled product design that considered stress concentration die profiles. Experiments involved cold forging various sheet metals (lead, brass, aluminium, and steel) with thicknesses ranging from 2mm to 6mm to assess their influence on the thickness and strain. An assumption was formulated using Solidworks to determine the appropriate sheet metal thickness based on the material type. This assumption, based on volume considerations, showed practical applicability for selecting sheet metals with thicknesses close to those designed in the numerical modelling. The results revealed that softer materials, such as lead and aluminium, closely approximated the design thickness, particularly in the central region of the die profile, with error deviations of 1.14 % and 4.36 %, respectively. In contrast, harder materials demonstrated larger deviations from the design, with minimum errors of 4.94 % for brass and 5.73 % for steel. All sheet metals underwent compressive strain in the central region of the die profile due to the stamping operation. This work demonstrates a practical approach for selecting sheet metals based on material and thickness considerations, providing insights into the behaviour of different materials during the cold forging process.

Modified cure cycles for increased fatigue performance of fiber metal laminates

Modified (MOD) cure cycles that deviate from the manufacturer’s recommended cure profile can reduce the inherent thermally induced residual stresses (TRS) in fiber metal laminates (FML). Literature shows that MOD cycles do not adversely affect the material properties but enhance the quasi-static material strength. However, the literature does not comprehensively discuss the impact of MOD cycles on material performance during cyclic fatigue loading. This paper, therefore, investigates how MOD cycles influence the fatigue characteristics of different FML layups made of carbon fiber-reinforced polymer (CFRP) and steel. The experimental results confirm that the quasi-static material strength and the modulus of the FML are increased when using MOD cure cycles. The evaluation of fatigue tests with digital image correlation, thermography, and electrical resistance measurements of notched specimens shows that a reduction of TRS delays damage initiation in the metal facesheets and decreases the crack growth rate until facesheet failure. The results further show that layup-dependent parameters, the maximum stress in the metal sheets, and metal sheet thickness significantly govern the evolution of fatigue damage. In summary, modified cure cycles are an efficient tool to enhance the quasi-static and fatigue performance of CFRP-steel hybrid laminates.

Re-manufacturing of Pre-deformed Automotive Sheet Metal Stamping Scrap Without Melting

Abstract The recycling of aluminium sheet metal typically involves shredding and re-melting, processes which are both energy-intensive and challenged by the presence of metallic contaminants. To mitigate these issues, this study explores an alternative approach: the re-manufacturing of deep-drawn parts directly from scrap aluminium sheets, thus bypassing the melting step. We used 2 mm thick Al-Mg sheet metal in H111 temper to produce simulated stamping scrap (miniaturized bonnets). Blanks were cut from these bonnets and secondary parts in a cross-cup geometry were deep-drawn using two different forming processes: warm-forming at 200 °C and O-temper forming at room temperature. The resulting maximum draw depths were 20-22 mm for warm-forming and 25-30 mm for O-temper forming. While warm-forming resulted in lower draw depths, O-temper forming led to coarse recrystallized grain formation in some regions. Our approach could significantly reduce the energy consumption associated with aluminium recycling.

Optimizing crash box design to meet injury criteria: a protocol for accurate simulation and material selection

The design of a deformation element or crash box that meets a given injury criterion based on deceleration requires careful consideration of physical properties and space requirements. Variations in material yield stress or geometry can result in statistical variations in the injury criterion output. Optimizing the crash box to fulfil two different injury criteria and two different energy levels may require more space than initially specified. In this study, we propose a protocol where the crash box is collapsed, and force–displacement is fitted to an equation. This fit is carried out with just two simulations and compared to 30 possible scenarios, obtaining a maximum error of 38.9%. With this initial fit, the appropriate thickness and yield stress can be chosen to perform crashes with two energy levels and monitor four injury values. With the ideal yield stress and sheet metal thickness, we introduce real statistical distributions using Monte Carlo design to perform 200 simulations and obtain 400 injury values for each design proposal. This technique ensures that the design will meet injury requirements for any possible combination of thickness and yield stress accepted by quality inspection. If only one simulation is performed, all designs meet the requirements, but only the last proposed design decreased the average injury to 9.2 g with a standard deviation of 2.68 g and a maximum value of 14.4 g, which is less than the required 15 g. This technique minimizes the risk of finding combinations of yield stress and thickness that produce an undesirable injury criterion.

A Numerical Modelling of V-Bending

In the study, a sheet metal is bent to analyze the punch force, Von Misses stresses and plastic strains on the metal for friction and non-friction cases. The 2-D v-bending forming is modelled in program. Model includes a die, a punch and a blank. Solid mechanics physics interface has been used in program. The analyze has been run with friction and non-friction cases for different strain-hardening exponents and sheet metal thicknesses. The sheet lengths and widths are 60 mm. Thickness of sheet metal is varied between 1.0 to 3.0 mm. The strain hardening exponent has been altered from 0.1 to 0.5. It is computed that the punch force has been increased as thickness of sheet metal and strain hardening exponent decreases. The achieved maximum punch force is at values of 1.12x105 N, 3.75x105 N and 4.05x105 N for thickness of 1.0-mm, 2.0-mm and 3.0-mm respectively when strain hardening exponent is 0.3. Also, as the strain hardening exponent increases from 0.1 to 0.5, the maximum punch force lowers from 2.03x105 N to 8.08x104 N for 1 mm thickness at friction case. Moreover, the maximum punch force reached up to 9.13x104 N for 1 mm thick sheet metal at non-friction case when the strain hardening exponent is 0.1. It is concluded that the maximum Von Misses stress has been calculated at the tip of sheet metal.

AI-assisted prediction of St14 steel sheets formability: Neural-fuzzy systems and crystal plasticity assessments

We've introduced a new technique leveraging artificial intelligence to determine in-plane forming limit strains in St14 sheet metals. A neural-fuzzy AI system was devised to predict safe points on forming limit diagrams, considering aspects like crystal texture, metal sheet thickness, and spherical punch diameter. Neural-fuzzy systems could be utilized in prediction of forming limit curves using linguistic data description. To obtain the data required for training the AI network, in-depth tests, including XRD, metallography, tensile testing, and Nakazima's hemisphere evaluations, were carried out to detail the metallurgical and mechanical properties of St14 sheet metal. Data on texture, the tensile curves, and grain morphology were then incorporated in crystal plasticity models to find hardening constants for St14's single crystals. Using these determined values, Nakazima's tests were replicated through multi-crystal aggregate configurations. We then undertook a comprehensive parameter investigation via 324 crystal plasticity simulations to shed light on the effects of texture, sheet depth, and punch dimensions on St14's formability. This rich dataset paved the way for training an adaptive neural fuzzy inference system (ANFIS), leading to substantial reductions in time and computational needs. The results validate that the ANFIS model offers accurate and reliable predictions, highlighting its viability for wider use in determining forming limit diagrams.

Multi-parameter similarity model-based lightweight design of battery electric vehicle body-in-white

The bending stiffness, torsional stiffness, and low-order modal frequencies of the body-in-white (BIW) are crucial factors in structural lightweight design. This paper introduces a BIW optimization approach for electric vehicles (BEVs) that integrates comprehensive sensitivity analysis and multi-parameter similarity models. The aim is to efficiently balance the BIW’s stiffness performance with minimal weight, while also managing potential manufacturing cost increases from design modifications. Firstly, the validity of the computational model is demonstrated by the BIW bending and torsion stiffness test and modal test. On this basis, the integrated sensitivity evaluation indexes of the structural member thickness parameters to the stiffness, weight and low-order modal frequency response of the BIW were calculated. The sheet metal thickness parameters of 17 structural members were preferred as design variables, and a multi-parameter similarity prediction model for BIW weight reduction design was constructed. Minimum weight, maximum stiffness and higher modal frequency of the BIW are defined as the optimization objectives. The optimal solution was finally solved using a multi-objective optimization algorithm. The results indicate a 1.582% reduction in weight of the BIW compared to the pre-optimization BIW. This paper delves into the intricate interplay between the parameters of the BIW’s structural components using simulation optimization techniques alongside experimental validation. This study not only proposes a new idea for the problem of how to efficiently and accurately determine the best optimization object from a large number of structural components in the development of vehicle structural safety, but also provides a research basis for automobile manufacturers to implement further weight reduction and optimization work on the BIW at the later stage of BEV development.

RESEARCH ON THE RELATIONSHIP BETWEEN THE THICKNESS AND THE STRUCTURAL CONDITION OF ROLLED METAL FROM LOW-CARBON LOW-ALLOY STEEL 10G2FB

When choosing steels for the design of high-rise and long-span buildings with increased load-bearing capacity, it is advisable to give preference to thick rolled steel from low-carbon, low-alloy steels, since it, with the same level of strength as construction steels, has a higher level of plasticity. At the same time, the problem of using thick rolled steel from low-carbon, low-alloy steels in the construction industry are the anisotropy of the rolled metal properties, which can increase with an increase in the thickness of the rolled metal. Currently, in Ukraine, controlled rolling is one of the most promising technologies of high-temperature thermomechanical processing for the production of thick rolled metal from low-carbon, low-alloy steels. At the same time, with an increase in the thickness of the rolled metal, which is produced with this technological scheme, the effect of the regulated formation of the structural state decreases due to the influence on the temperature of the surface layers of the rolled metal, the thermodynamic state of the inner layers and the inability of the rolling equipment available at domestic enterprises to deform the metal over the entire cross-sectional area. Therefore, the task of obtaining such a structural state in the thick sheet metal roll, which will ensure the reduction of the anisotropy of the properties, which will allow the use of such rolled metal in the construction industry, is urgent. Purpose of the article is to study of the structural state of low-carbon low-alloy steel 10G2FB, which was produced using the technology of controlled rolling, depending on the thickness of the rolled metal. Conclusion. The relationship between the structural state and the thickness of rolled metal from low-carbon low-alloy steel 10G2FB, which was produced by controlled rolling technology, was studied. It was established that with the increase in thickness, the percentage content of the ferrite component increases with a simultaneous decrease in the percentage content of the pearlite phase. It is shown that changes in the formation languages of structural components begin with an increase in the thickness of the rolled metal over 30 mm, which is explained by the influence of the temperature of the inner layers on the processes of forming the structural state, namely, with an increase in the thickness of the rolled metal, the thermodynamic rate of phase transformations in the middle layers of the rolled metal samples decreases. This conclusion is confirmed by two factors: firstly, an increase in the size of pearlite colonies, and secondly, a change in the morphology of the cementite framework of pearlite colonies from zigzag (thickness 16...30 mm) to ribbon (thickness 40...100 mm).

Analysis and optimization of stamping and forming process of bearing outer ring

To address the common issues of wrinkling, tearing, and uneven wall thickness in the actual sheet metal stamping process of the outer ring of needle roller bearings, this study analyzes critical technical indicators such as forming limits, thickness distribution, and principal strains in the forming process in detail. Three-dimensional models of the concave and convex dies were constructed. The effects of different process parameters, including stamping speed, edge pressure, sheet metal thickness, and friction coefficient, on the quality of the forming parts were investigated by varying these parameters. Subsequently, the orthogonal experimental method was used to determine an optimal experimental group from multiple sets of experiments. It was found that under the process parameters of a stamping speed of 3000 mm/s, edge pressure of 2000 N, sheet metal thickness of 0.9 mm, and friction coefficient of 0.125, the forming quality of the outer ring of the bearing is ideal.

Single pass laser vacuum welding of thick steel plates using electromagnetic support

The increasing demand for renewable energy produced by offshore wind turbines goes along with an increased demand in the production of offshore wind turbine foundations, so called “monopiles”, which are made by joining thick metal sheets. The industrial standard of multi-layer submerged arc welding (SAW) for joining of thick metal sheets is the current bottleneck in the production of monopiles. A possible increase in productivity by the implementation of high-power laser welding in a newly developed mobile vacuum chamber (MoVac) and an electromagnetic root support is the subject of this study. Single run butt welds are performed in flat position on S355 mild steel of thicknesses up to 80 mm using a disc laser system with 1030 nm wavelength and a maximum output of 60 kW. The laser optic is fixed on the MoVac-System which is held and manipulated by an articulated robot.

3D oscillation-assisted laser beam cutting with time-synchronized process monitoring

A current subject of research is to optimize the laser cutting process in terms of process efficiency and cut edge quality, especially in thick sheet metal cutting. One approach is to influence the energy distribution in the cut kerf using various beam shaping options, including dynamic beam oscillation. The challenge lies in the fact that the oscillation parameters of beam shaping, which are added to the conventional laser cutting process, create an infinite number of new parameter combinations. For the first time, a complete system has been set up at the IWS in cooperation with the CMA with the aid of the process monitoring options. This system is intended to help provide deeper insights into the processes taking place in the cutting zone and thus contribute to an expanded understanding of the process. First experiments were carried out to investigate the influence of the 3D beam oscillations on the cut quality and cutting speed.

Strength Evaluation of Welded Aluminum T-joints, as a Function of Its Welding Process, Execution, Filler Material, and Weld Root Penetration

Essential requirements for weld seams are the long-term transmission of static and time-varying forces. Requirements for the verification of laser welded fillet weld T-joints are proposed in this paper, since there is no established procedure in this field for laser welding. More precisely, the strength of laser MIG hybrid welded AlMg3Mn T-joints, made from 3.5 mm thick sheet metal are determined, depending on the penetration of their weld root gap. This allowed the unwelded root gap to be related to the decrease in strength, even though this is more apparent with dynamic than with static loading. In addition, the influence of filler material, single and mutual-sided MIG welds have been added to this comparison. Filler materials used are the related AlMg2.7Mn or the extraneous AlSi5.

Investigating the effect of input parameters on tool wear in incremental sheet metal forming

Abstract Over the years incremental sheet metal forming (ISMF) has developed as a futuristic technique in which the metal sheets are transformed into the final product with the use of a solid metallic rod having a designed end, rather than a dedicated die. The production lead time is quite high in this process as compared to the conventional sheet forming methods. ISMF is most suitable for developing model for the purpose of research and development, manufacturing of the customized part and for low-volume production. Tool life is an important criterion for determining feasibility of any manufacturing process. The sliding of the forming tool over the clamped metal worksheet during the ISMF is another important aspect for understanding the tool-wearing behaviour. The present study has investigated the wearing of the 440C grade steel forming tool during the ISMF of aluminum grade AA3003-O. It has examined the process statistically to establish that the step downsize (P = 0.021) and sheet metal thickness (P = 0.005) significantly influence the wearing of 440C steel tool. The coefficient of performance, i.e., R 2 has been reported as 92.0 % with an adjusted R 2 of 81.9 %.

Modelling of kerf width and surface roughness using vibration signals in laser beam machining of stainless steel using design of experiments

Manufacturing industries are increasingly interested in laser beam machining as an efficient material removal process. Accordingly, there is great motivation in the modelling of the machining process to understand the physics behind the machining process in order to improve the machining efficiency. The present study made an attempt to predict surface roughness, kerf width and metal removal rate by utilizing the vibration signals measured during the laser beam machining of AISI 304 stainless steel. As per Taguchi’s L9 design of experiments, nine experiments were conducted at three levels of laser power (2.0, 1.5 and 1.0 kW), laser frequency (10, 8 and 6 kHz), cutting speed (3.0, 2.5 and 2.0 m/min) and nozzle tip distance (1.2, 1 and 0.8 mm) on 6 mm thickness of sheet metal and the vibration of sheet metal was measured using an accelerometer. It was observed that, the sheet vibration along the cutting direction increased the metal removal rate and sheet vibration perpendicular to the cutting direction caused surface roughness. Mathematical models were developed with the vibration data and predicted the surface roughness, kerf width and metal removal rate. The root mean square error of the responses was calculated as 0.615 µm, 5.44 µm and 0.259 m3/min for surface roughness, kerf width and metal removal rate respectively, demonstrating a significant correlation with experimental results. Furthermore, effect of laser power, laser frequency, cutting speed and nozzle tip distance on the surface roughness, kerf width, heat affected zone and metal removal rate was studied. The laser power and cutting speed have significant effect on these responses. Finite element modelling based simulation was carried out and studied effect of molten metal temperature on the heat affected zone. Temperature in the molten pool reached to maximum of 1773 K and the heat affected zone increased, when the laser power increased to 2.0 kW. The root mean square error between the measured and simulated heat affected zone was computed as 4.68 µm, indicating a good correlation between both.

Investigating the surface roughness of calamine brass in incremental sheet metal forming

Incremental sheet metal forming (ISMF) is an emerging metal sheet forming technique. ISMF does not require any special/dedicated dies for shaping the metal sheet into a desired part. The forming technique is an alternative for customized part generation, prototype making, and low-volume product manufacturing. The experimental investigation is focused on finding the significance of process parameters on the average surface roughness of the ISMF part. Limited process parameters were taken that majorly influenced the ISMF. Calamine brass (Cu67Zn33) is preferred for home alliance and grocery items because of its sustainability and corrosion-resistant properties therefore thin sheets of it were taken as worksheets. The surface roughness of the formed part was measured through atomic force microscopy (AFM) technique. Statistical analysis confirmed that the step-down size, feed rate of the tool, wall angle, and the thickness of metal sheet whose P-values were 0.013, 0.052, 0.030, and 0.036 respectively were significant for average surface roughness. Their contribution was calculated as 76.71%, 0.025%, 13.67% and 0.89% respectively.

Effect of Sheet Thickness on Forming Precision in Single Laser Shock Forming with Mold

Laser shock forming (LSF) is one of the sheet metal dynamic forming techniques that employ laser-induced shock waves to form sheet metal into complex three-dimensional parts rapidly. This work investigates the effect of sheet thickness on the forming precision in laser shock forming with mold. ABAQUS/Explicit analysis software is adopted to study the effect of sheet metal thickness on forming accuracy. The corresponding forming experiments with sheet thickness arranged from 0.1mm to 0.4 mm are conducted to validate those numerical values. The numerical and experimental results indicate that the sheet thickness plays an important role in the precision of the formed parts, with the increase of sheet thickness, the forming precision is decreased.

Experimental study and examination of failure zone factors and causes of destruction of thick metal sheets of rail cranes: mechanical properties, chemical analysis and metallography

Experimental study and examination of failure zone factors and causes of destruction of thick metal sheets of rail cranes: mechanical properties, chemical analysis and metallography

Method of Stamping the Progression of a Beverage End Rivet of a Thinner Sheet of AW-5182 Alloy.

This paper presents a new solution for shaping the rivet progression of a beverage end. The classic method uses three operations to press the cylindrical rivet using 0.208 mm and 0.203 mm thick sheets. The increasing demand for aluminium alloys is prompting measures to make more efficient use of this raw material. One possible solution is to produce packaging from ever thinner sheets. This requires the design of new tooling and the preparation of an appropriate technological process. A method has been developed to stamp a hexagonal-shaped rivet from 0.200 mm thick sheet metal, increasing the number of stamping operations to four. The proposed method was verified through a numerical analysis using the PAM STAMP 2022.0 software package. It was found that for appropriately shaped tools, sheet thicknesses of the stamped component could be achieved that were not less than those for the currently used technology, thus eliminating any possible break in the material structure. Suitable tools and experimental stamping tests were carried out for the developed process. In the simulations, the material Al5182_iso_Xmm was adopted from the programme database, while the experiments were performed on a laboratory press using AW-5182-H48 sheets with a thickness of 0.200 mm. The purpose of the study was to determine the validity for the proposed method of forming the rivet of the beverage end.

Numerical investigation to study the influence of thickness and electrical conductivity of metal-sheets on the LOI-Point of a PEC sensor

ABSTRACT The aim of this article is to determine a similar point to the Lift-Off intersection point (LOI) obtained from a geometric configuration of a Pulsed Eddy Current (PEC) sensor. This configuration enables easy determination of the LOI point through a single measurement, thus avoiding measurement noise. The sensor consists of an external excitation coil and two internal probes that overlap and have similar characteristics for reception. The similar point LOI is determined by the intersection of the signals from the transient response of the sensor’s internal probes. Importantly, this point is independent of lift-off variation. Moreover, the amplitude and time measurement of this point vary with the variation of the physical and geometric properties of the sample. To assess the effectiveness of this similar point, a numerical code based on electromagnetic phenomena was developed. This code investigates the impact of thickness and electrical conductivity of metal sheets on the response of the PEC sensor, both with and without a ferrite core at this point. Additionally, a practical sensor prototype was constructed to validate the results obtained from the numerical model. The obtained results demonstrated a strong correlation between the numerical and experimental outcomes, thus confirming the effectiveness of the proposed technique.