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1

Application of laser barcode technology to sheet metal parts identification

Morawiński Łukasz, Świłło Sławomir, Kocańda Andrzej

Zeszyty Naukowe. Organizacja i Zarządzanie / Politechnika Śląska

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2022

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z. 162

501--516

EN

Purpose: In the development of ideas for Industry 4.0, information about the element production cycle has become more and more important. Knowledge of the subsequent forming processes, determination of the machine on which the process has been carried out and of the type and wear of the tool, leads to smart production management, which plays an increasingly important role in the metal forming industry. To meet the current expectations for these challenges, an advanced technology needs to be introduced for monitoring the manufacturing processes by deploying flexible solutions. This technology must include, but not be limited to, identifying and tracking the product using laser marking. Design/methodology/approach: Laser marking allows a permanent mark in the form of a barcode to be applied to the sheet metal surface. Commonly used marking methods and the condition of the sheet metal surface can affect the marking contrast. This paper presents a concept for recording individual stages of sheet metal forming and determination of the impact of the laser marking technology on the contrast of the applied barcode. To ensure accurate control of the deformation stages, the bulging process of the spherical dome has been used as an example. Findings: Analysis of the influence of laser marking method on the barcode recognition accuracy can contribute to the development of smart management of the production process according to the idea of Industry 4.0. Research limitations/implications: A large plastic deformation has been applied to the sheet metal surface and no limitation in a barcode reading process (using vision scanning technology) was indicated. Also, the geometry deformation (different angle view of the CCD camera) of the barcode image has introduced no additional problems with a barcode reading. Originality/value: The optimal parameters of a laser marking technique for barcode marking, which are critical for the material that is subjected to metal forming operations that deform it, have been studied. The results shows that traceability is an attractive solution for tracking technological data in the production chain for a single-shaped product.

2

Multivariate modelling of effectiveness of lubrication of Ti-6Al-4V titanium alloy sheet using vegetable oil-based lubricants

Trzepieciński Tomasz, Szpunar Marcin

Advances in Materials Science

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2021

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Vol. 21, nr 2(68)

26--39

EN

The article presents the results of modelling the friction phenomenon using artificial neural networks and analysis of variance. The test material was composed of strip specimens made of 0.5-mm-thick alpha-beta Grade 5 (Ti-6Al-4V) titanium alloy sheet. A special tribotester was used in the tests to simulate the friction conditions between the punch and the sheet metal in the sheet metal forming process. A test called the strip drawing test has been conducted in conditions in which the sheet surface is lubricated with six environmentally friendly oils (palm, coconut, olive, sunflower, soybean and linseed). Based on the results of the strip drawing test, a regression model and an artificial neural network model were built to determine the complex interactions between the process parameters and the friction coefficient. A multilayer perceptron with one hidden layer and eight neurons in this layer showed the best fit to the training data. The network training was conducted using three algorithms, i.e. Levenberg-Marquardt, back propagation and quasi-Newton. Taking into consideration both the coefficient of determination R2 (0.962) and S.D. ratio (0.272), the best regression characteristics were presented by the network trained using the Levenberg-Marquardt algorithm. From the response surfaces of the quadratic regression model it was found that an increase in the density of lubricant at a specific pressure causes a reduction in the coefficient of friction. Low density and high kinematic viscosity of the oil leads to a high coefficient of friction.

3

Modelling anisotropic phenomena of friction of deep-drawing quality steel sheets using artificial neural networks

Trzepieciński Tomasz, Lemu Hirpa G., Chodoła Łukasz, Ficek Daniel, Szczęsny Ireneusz

Advances in Materials Science

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2021

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Vol. 21, nr 3(69)

31--42

EN

This paper presents a method of determining the coefficient of friction in metal forming using multilayer perceptron based on experimental data obtained from the pin-on-disk tribometer. As test material, deep-drawing quality DC01, DC03 and DC05 steel sheets were used. The experimental results show that the coefficient of friction depends on the measured angle from the rolling direction and corresponds to the surface topography. The number of input variables of the artificial neural network was optimized using genetic algorithms. In this process, surface parameters of the sheet, sheet material parameters, friction conditions and pressure force were used as input parameters to train the artificial neural network. Some of the obtained results have pointed out that genetic algorithm can successfully be applied to optimize the training set. The trained multilayer perceptron predicted the value of the friction coefficient for the DC04 sheet. It was found that the tested steel sheet exhibits anisotropic tribological properties. The highest values of the coefficient of friction under dry friction conditions were registered for sheet DC05, which had the lowest value of the yield stress. Prediction results of coefficient of friction by multilayer perceptron were in qualitative and quantitative agreement with the experimental ones.

4

Sheet metal forming using environmentally benign lubricant

Więckowski Wojciech, Adamus Janina, Dyner Marcin

Archives of Civil and Mechanical Engineering

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2020

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Vol. 20, no. 2

307--319

EN

Sheet metal forming belongs to one of the most important technologies enabling the production durable but quite lightweight metal parts. The quality of the drawn parts depends on the deformed sheet metal, applied forming technology and process parameters, such as contact pressure, relative velocity, temperature or lubrication. The forming of steel (1.4021) parts using benign lubricant is analysed. The paper proposes replacing conventional mineral/synthetic lubricants with ones based on vegetable oils and boric acid. The effectiveness of the lubricants was assessed in laboratory strip drawing and cupping tests, and in production. An oil-based lubricant with an additive of boric acid is very effective in reducing frictional resistance and protecting the forming tools against galling.

5

Finite element based prediction of deformation in sheet metal forming process

Kraska Damian, Trzepieciński Tomasz

Applied Computer Science

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2018

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Vol. 14, no 3

43--53

EN

In this paper the sheet forming process of cylindrical drawpieces was sim-ulated based on the finite element method by the explicit approach in the pres-ence of contact conditions with isotropic and anisotropic friction. The ex-perimental and numerical results obtained in the Abaqus finite element (FE) based program are presented. The aim of the experimental study is to analyse material behaviour under deformation and in addition to use the results to verify numerical simulation results. It was found that, although, the anisotropy of resistance to friction affects the height of ears, the influence of the friction formulation is relatively small in comparison with material anisotropy. The study indicates that FE analysis with 3-node triangular shell element S3R elements ensures the best approximation of the numerical results to the real process when both material and friction anisotropy are taken into account.

6

Numerical simulation of forming titanium thin-wall panels with stiffeners

Adamus Janina, Winowiecka Julita, Dyner Marcin, Lacki Piotr

Advances in Science and Technology. Research Journal

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2018

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Vol. 12, no 1

54--62

EN

Due to the increase in the application of titanium components made of thin titanium sheets, in the work titanium panels made of 4 mm thick sheets are analysed. To increase the rigidity of the panels, some cross-shaped stiffeners were made. Such panels enable a reduction in weight while maintaining the existing strength of the drawn parts. Three kinds of commercially pure titanium are considered: Grade 1, 2 and 3. Numerical calculations were performed with PamStamp 2G based on the finite element method. The basic mechanical and technological properties of the analysed sheets, which are necessary for numerical modelling, were determined by static tensile testing. The friction coefficient was assumed based on the literature. On the basis of the performed numerical analyses, it was stated that the proper forming of panels with stiffeners depends not only on the drawability of the sheets but also on the technological parameters such as blank holder force and frictional conditions.

7

Forming Of Spherical Titanium Cups From Circular Blanks With Cutouts On The Perimeter

Lacki P., Adamus J., Więckowski W., Winowiecka J.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 2A

829--834

EN

Despite substantial demand for drawn parts made of high-strength sheet metal (including titanium alloys) observed in the modern industry, particularly automotive and aviation, their application remains insignificant. This results from the fact that such sheet metal shows poor plasticity and its cold-forming is almost impossible. Low drawability makes it impossible to obtain even such simple shapes as spherical cups. The authors of this study developed circular sheet-metal blanks with cutouts on their perimeter. The blanks allow for cold forming of spherical cups from Ti6Al4V titanium alloy sheet metal using conventional rigid tools. The cutouts proposed in the study affect plastic strain distribution, which in turn leads to an increase in forming depth by about 30%. The numerical analysis, performed using the PamStamp 2G System software based on finite element method, was verified experimentally.

PL

Mimo, iż nowoczesny przemysł, głównie motoryzacyjny i lotniczy, zgłasza zapotrzebowanie na wytłoczki z wysokowytrzymałych blach metalowych, w tym stopów tytanu, ich zastosowanie jest znikome. Wynika to z faktu, że blachy te mają małą plastyczność i ich tłoczenie na zimno jest niemal niemożliwe. Niska tłoczność uniemożliwia kształtowanie nawet tak prostych geometrii jak czasze kuliste. W ramach niniejszej pracy opracowano kołowy wykrój z wycięciami na obwodzie, który umożliwia kształtowanie na zimno kulistych czasz z blachy ze stopu tytanu Ti6Al4V przy użyciu klasycznych, sztywnych narzędzi. Zaproponowane wycięcia wpływają na zmianę rozkładu odkształceń plastycznych, co w konsekwencji prowadzi do zwiększenia głębokości tłoczenia o około 30%. Analizy numeryczne, wykonane programem PamStamp 2G bazującym na metodzie elementów skończonych, zweryfikowano doświadczalnie.

8

EBW titanium sheets as material for drawn parts

Adamus J., Lacki P., Motyka M.

Archives of Civil and Mechanical Engineering

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2015

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Vol. 15, no. 1

42--47

EN

The growing demand for high strength, lightweight and corrosion-resistant drawn parts has created increasing interest in the use of titanium and its alloys. Additional benefits may result from the use of tailor-welded blanks, allowing for significant savings in material, and the possibility of applying higher strength sheets exactly where needed. When forming welded blanks, it is necessary to overcome many technological barriers which are not reflected in technical literature. Therefore, some prior experience in numerical simulations is needed before embarking on further studies of welded blanks formability. For this purpose, it is necessary to determine the mechanical parameters of the base materials, as well as the fusion and heat-affected zones. The paper is devoted to the analysis of an electron beam welded joint made of commercially pure titanium Grade 2 and titanium alloy Grade 5. Light microscopy was used for examination of the joint microstructure and determination of the size of the specific joint zones. The mechanical parameters of the base materials were specified in a tensile test, while the material properties of the fusion and heat-affected zones were estimated on the basis of the relationship between the material hardness and strength assuming that the yield stress is directly proportional to the material hardness. To do this, a scratch test and microhardness measurements (using small load) were carried out. The obtained results allow for improvement to the numerical model of sheet-metal forming welded blanks and consequently, it will allow for better agreement between the numerical and empirical results.

9

Constitutive modelling effect on the numerical prediction of springback due to a stretch-bending test applied on titanium T40 alloy

Maati A., Tabourot L., Balland P., Ouakdi E. H., Vautrot M., Ksiksi N.

Archives of Civil and Mechanical Engineering

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2015

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Vol. 15, no. 4

836--846

EN

Nowadays, numerical simulation by finite element analysis is an essential tool that allows performing virtually sheet metal forming processes, and therefore to reproduce various phenomena such as springback (SB) and necking that are generated by plastic deformation. However, the quality of the model used to represent the mechanical behaviour is a determining factor for the realism of numerical simulations. To perform well, the model must reproduce all the properties of the material such as the anisotropy and the strain hardening induced by plastic deformation. The main purpose of this work is to show, by means of numerical simulations, the influence of constitutive modelling on the prediction of the degree of SB in the case of a stretch bending test. Tests have been carried out on titanium sheets which have a wide range of applications for high tech industries because of specific mechanical and physical properties. At the same time, we have investigated the dependence of some process parameters such as the clamping force on SB. In order to prove the accuracy and reliability of the proposed finite element model, experimental data were used to compare with the numerical results.

10

Evaluation of drawability of titanium welded sheets

Lacki P., Adamus J., Więckowski W., Winowiecka J.

Archives of Metallurgy and Materials

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2013

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Vol. 58, iss. 1

139-143

EN

In the paper experimental and numerical results of sheet-metal forming of titanium welded blanks are presented. Commercially pure titanium Grade 2 (Gr 2) and Ti6Al4V titanium alloy (Gr 5) are tested. Forming the spherical cups from the welded Gr 2 || Gr 5 blanks, and uniform Gr 2 and Gr 5 blanks is analysed. Numerical simulations were performed using the PamStamp 2G v2012 program based on the finite element method (FEM). Additionally, drawability tests using the tool consisting of die, hemispherical punch and blank-holder were carried out. Thickness changes and plastic strain distributions in the deformed material are analysed. The obtained results show some difficulties occurring during forming of the welded blanks made of titanium sheets at the same thicknesses but at different grades. It provide important information about the process course and might be useful in design and optimization of the sheet-titanium forming process.

PL

W artykule przedstawiono wyniki badań doświadczalnych oraz symulacji numerycznych procesu tłoczenia spawanych wsadów typu Tailor-Welded Blanks wykonanych z blach tytanowych. Przeprowadzono analizę procesu kształtowania czaszy kulistej z wsadu spawanego oraz z materiałów jednorodnych: Grade 2 i Grade 5. Obliczenia numeryczne przeprowadzono przy użyciu programu PamStamp. Dodatkowo przeprowadzono próby tłoczności (próby wybrzuszania stemplem sferycznym) przy zastosowaniu specjalnie przygotowanego narzędzia składającego się z matrycy, półkulistego stempla oraz pierścienia dociskowego. Dokonano oceny rozkładów odkształceń plastycznych w materiale wytłoczek oraz zmian grubości scianek wytłoczek. Uzyskane wyniki wskazują na trudności występujące podczas kształtowania tytanowych blach spawanych oraz dostarczają informacji o przebiegu tego typu procesu. Tym samym uzyskane wyniki mogą być przydatne na etapie projektowania i optymalizacji procesów tłoczenia.

11

A study of the impact of anti-adhesive coatings on the sheet-titanium forming processes

Adamus J., Lackner J. M., Major Ł.

Archives of Civil and Mechanical Engineering

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2013

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Vol. 13, no. 1

64--71

EN

The paper describes proposition for minimisation of both friction and formation of titanium protrusions on steel tools during sheet-titanium forming. Such a process poses a significant challenge not only because of the limited ability to plastic deformation of the titanium sheets, but also because of the low tribological properties. Titanium sheets have extremely high propensity to form titanium protrusions on steel tools, which aggravates or even makes obtaining the drawn-parts with a smooth surface impossible. In order to reduce or completely eliminate the formation of titanium protrusions on the tools technological lubricants should be used. Unfortunately, due to high surface pressure the lubricant film is interrupted frequently. Thus, the authors propose that the tool surfaces (dies and blank-holders) are covered with anti-adhesive coatings, which protect the tools against creation of the titanium protrusions in case of lubricant film break. The paper presents some results of tribological tests. In the strip-drawing test, results of different frictional pairs are presented based on anti-adhesive coatings deposited on the tool surfaces. The decrease in titanium protrusion formation on the steel tools thanks to the use of anti-adhesive coatings was confirmed in the roughness measurements of the tool surface after the strip-drawing test.

12

Examination of the Strength and Ductility of AA-1050 Material Shaped with the MUlti-Stage Deep Drawing Method

Karali M.

Archives of Metallurgy and Materials

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2011

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Vol. 56, iss. 2

223-230

EN

Deep drawing materials are easily shapeable materials, because of their high ductility. Aluminum alloy materials are classified in the deep drawing materials group because they are easily shapeable. In order to increase the strength, materials are made an alloy by adding some chemical additives. They are also provided strength increasing by tempering. Normally, materials harden when reshaped under plastic deformation. Reshape the shaped materials harden while reducing its ductility. In this study, changes in mechanical properties immediately after the AA-1050 (T0) sheet material is shaped by the multi-stage deep drawing method and after storage were investigated. It was calculated that a 4-stage shaping is needed for a tube production at selected sizes. Deep drawing treatments are made in sizes of these stages. Samples were collected from each cold-shaped intermediary form. Mechanical properties of this materials are determined by applying tensile test. Some basic parameters, like tensile stresses, max. uniform strain rates, strain hardenings and strength coefficients, are investigated and compared. Obtained data were explained using graphs. It was observed that tensile strength increased and strain quantities were reduced at every stage. It is also seen an increase in strain hardening index.

PL

Stopy do głębokiego tłoczenia są materiałami łatwo odkształcalnymi z powodu ich wysokiej plastyczności. Stopy aluminium należą do grupy materiałów odpowiednich do wytłaczania, ponieważ są łatwo odkształcalne. W celu zwiększenia wytrzymałości, do aluminium dodawane są pewne dodatki stopowe. Wytrzymałość wzrasta także po odpuszczaniu. Zwykle, materiały umacniają się wskutek deformacji plastycznej, co wiąże się ze zmniejszeniem plastyczności. W tej pracy, badano zmiany właściwości mechanicznych stopu AA-1050 (T0) bezpośrednio po odkształceniu przez wielokrotne głębokie tłoczenie oraz po okresie przechowywania. Obliczono, że do produkcji rur w wybranych rozmiarach potrzebne jest 4-etapowe odkształcenie. Próbki do badań pobrane były po każdym etapie odkształcenia na zimno. Właściwości mechaniczne tych materiałów zostały zbadane przez zastosowanie próby rozciągania. Niektóre podstawowe parametry, takie jak naprężenie rozciągające, maksymalna jednorodna prędkość odkształcenia, umocnienie po odkształceniu i wspłóczynniki siły, zostały zbadane i porównane. Uzyskane dane zostały przedstawione za pomocą wykresów. Stwierdzono, że wytrzymałość na rozciąganie wzrasta a stopień odkształcenia maleje po każdym etapie odkształcenia. Obserwowano także wzrost wskaźnika umocnienia odkształcenia.

13

Analysis of spring-back during forming of the element made of AMS 5604 steel

Adamus J., Lacki P., Łyźniak J., Zawadzki M.

Archives of Metallurgy and Materials

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2011

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Vol. 56, iss. 2

422-430

EN

Spring-back poses a serious problem during the design of the sheet-metal forming processes due to difficulties in obtaining the correct shape and dimensional accuracy of the stamped elements. Forming with blank preheating is one of the methods of prevention against spring-back effect. However, this solution involves cost increase resulting from the additional operation of material heating and necessity of material protection against oxidation. In the paper forming of an element made of AMS 5604 steel, which is a part of aircraft engine deflector, has been analysed. The work aimed at determination of the spring-back effect arising during two-time forming on deviation of the basic size of the drawn-part from nominal one. Basing on the numerical analyses an optimum yield point for the deformed material, which assures maximum deviation from the basic size lower than 0.1 mm, has been also determined. Change in the yield point value was obtained thanks to heating up of the blank material before forming.

PL

Zagadnienie sprężynowania powrotnego stanowi istotny problemem przy projektowaniu procesów kształtowania blach na zimno ze względu na trudności z otrzymaniem odpowiedniej dokładności kształtowo-wymiarowej elementów. Jednym ze sposobów eliminacji sprężynowania powrotnego jest kształtowanie z wstępnym podgrzewaniem materiału wyjściowego. Takie rozwiązanie wiąże się jednak z dodatkowymi kosztami wynikającymi z operacji nagrzewania materiału i konieczności jego zabezpieczania przed utlenianiem. W artykule analizowano kształtowanie elementu ze stali AMS 5604, stanowiącego fragment owiewki silnika lotniczego. Celem pracy było określenie wpływu skutków sprężynowania powrotnego powstającego podczas "dwukrotnego" tłoczenia na odchylenie wymiarów wytłoczki od wartości nominalnych Na podstawie analiz numerycznych określono również optymalną granicę plastyczności materiału zapewniającą otrzymanie maksymalnego odchylenia od wymiaru nominalnego mniejszego niż 0,1 mm. Zmianę wartości granicy plastyczności uzyskano poprzez podgrzanie blachy przed tłoczeniem do odpowiedniej temperatury.

14

Comparison of technology of forming the sheet metal by numerical simulations

Pahole I., Puc M., Vaupotič B., Balič J.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 18, nr 1-2

403--406

EN

Purpose: The paper is concerned about the problems in forming low-carbon and stainless sheet metal in paralel on the same tools. It describes the properties of stainless sheet metal and the comparison with ordinary sheet metal of DC04 quality. Differences in physical properties pose a source of problems occurring in forming both sheet metals of the same geometry. Design/methodology/approach: Numerical simulation methods of deep drawing have been used for planning the technology of forming low-carbon and stainless sheet metal. For establishing basic properties of material the conventional testing methods have been used. Findings: The target of researches was to find out what changes have to be made in the forming tools, when the sheet metal from stainless steel is formed. Research limitations/implications: : Comparison of formability of sheet metals was limited only to materials suitable for use in production of household appliances. Practical implications: The research is practically employed in forming sheet metal parts for household appliances. Originality/value: By the use of the method described it is possible to determine in advance, how the forming tool must be made. Our aim was to make a forming tool suitable for forming sheet metal from stainless and low-carbon steel. The paper presents actual constructions.

15

Experimental study of the influence of blankholder force on spring-back of sheet metal

Chirita B.

Archives of Civil and Mechanical Engineering

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2003

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Vol. 3, no 1

5-12

EN

Spring-back is the main defect of the U-shaped parts. After removal of tools, the U-shaped part undergoes significant modification of the angles between the bottom, the sidewall and the flange, and also a curvature of the sidewall appears. The blankholder force is an important factor in controlling the size of spring-back parameters. The present paper is an experimental study of how blankholder force influences spring-back phenomenon.

PL

Powrotne odkształcenia sprężyste są zasadniczą wadą wyrobów tłoczonych w kształcie li-tery U. Po usunięciu kształtujących narzędzi zmieniają się istotnie kąty pomiędzy dnem, ścia-nami bocznymi i kołnierzem wyrobu, a także pojawia się krzywizna ścian bocznych. Siła doci-skacza jest bardzo ważnym czynnikiem decydującym o wartości sprężystych odkształceń powrotnych. W pracy przedstawiono badania wpływu siły dociskacza na zjawisko powrotnego sprężynowania wyrobów w kształcie litery U. Do badań użyto blachy ze stopu aluminium o grubości 1 mm. Siłę dociskacza zmieniano w zakresie od 0,25 do 2,06 kN, zgłębienie stem-pla było stałe i wynosiło 50 mm. Stwierdzono, że zwiększenie siły dociskacza powoduje zmniejszenie kątów powrotnych odkształceń sprężystych pomiędzy dnem a ścianami bocznymi oraz ścianami bocznymi a kołnierzem, natomiast zwiększa się krzywizna ścian bocznych. Jest to wynikiem bardziej równomiernego rozkładu naprężeń wzdłuż grubości blachy.