bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of scrap originating trace elements on the properties of low alloyed steels
Authors: Ahmed Shahroz , Sabr Ali , Peltola Ari , Oja Olli , Järn Sanna , Kaijalainen Antti , Penney David , Peura Pasi 
Published: June 2023

Abstract
The present intention to reach fossil-free steel manufacturing will inevitably result in an increase in the use of steel scrap as a raw material for steel production. Consequently, the amounts of elements, seen as impurities, will increase in steels. This has already been seen in electric arc furnace (EAF) processed steels, where the Cu and Sn levels have doubled in some cases after 1980’s. This may cause problems, as it is well-known, that some impurity elements have harmful effects on the properties of steel. This has been widely studied in low-alloy steels containing chromium and molybdenum which are widely used in components for the petroleum and electrical power generation applications. However, limited number of studies have been performed on formable steel grades, and the published reports/articles have mostly concentrated on the effects of P and B. Thus, there is still a need to understand the roles of other impurity elements. In the present study, a formable C-Mn steels containing additions (either individually or in combination) of Cu and Sn is investigated. The samples were cold rolled and annealed following typical time-temperature profiles of modern continuous annealing lines. Mechanical and forming properties (incl. bending and cupping tests) are determined as well as elemental profile analysis is conducted. The results identify that minor additions of impurity elements, in this case Cu and Sn, does not affect the mechanical and forming properties of low alloyed formable steel grades considerably.
Performance of stringer sheet parts under static and dynamic load
Authors: Biffar S , Groche P 
Published: June 2023

Abstract
The stringer sheet forming process chain enables the cost-effective production of components with significantly increased stiffness for mass markets such as the automotive sector. In the first process step, a stringer is added to a conventional sheet by laser welding. In the subsequent process step, the stringer sheet parts are formed by a deep drawing operation. Previous investigations of component performance focused in particular on the static stiffness of the stringer sheets. The behavior under dynamic load, such as in crash events, has not been systematically investigated to date. Static testing focused on the stringer height as the only influence on part performance. This study characterizes the crash performance of stringer sheet components by means of a drop hammer test. The energy absorption of the components is evaluated in the experiment based on the rebound height of the drop hammer, whereas the structural integrity is characterized based on the maximum dynamic as well as permanent deformation. Furthermore, a quasi-static compression test is carried out to obtain the static stiffness of the parts. In these tests, the geometric design of the stringer sheets as well as two forming process parameters are varied individually. The influence of these parameters on the static stiffness, energy absorption and structural integrity is assessed and discussed on their own and with regard to their influence on the part weight.
Multi-functional SMC-aluminum battery tray to drive lightweight design
Authors: Schmerler R , Drebenstedt C , Machhammer M , Gong G , Wolf P 
Published: June 2023

Abstract
Functional integration and lightweight design are important tasks especially for modern electric vehicles. Development of multi-functional assemblies for the battery box of the future is one of the challenges in the field of electric mobility. The housing must perform many tasks: structural stiffening and sealing (waterproofness) as well as crash protection and thermal management for the batteries. In this paper results from a new developed multi-functional assembly of a SMC-aluminum battery tray will be presented and discussed. The outer housing shell is manufactured by forming SMC directly on an aluminum sandwich component in one stroke compression molding. Furthermore, passive temperature control functions are integrated into the core of the aluminum sandwich realized with switchable air-cooling and phase-change-material integrated into the foam. Additionally, sensors for structural health monitoring, temperature and humidity are integrated. Finally the process design and manufacturing tests will be explained.
Evaluation of anisotropic fracture in AA1050-O sheet using uncoupled ductile fracture models with Hill48 plasticity
Authors: Gupta Aishwary , Hou Yong , Hariharan K , Han Heung Nam , Lee Myoung-Gyu 
Published: June 2023

Abstract
Uncoupled ductile fracture models have gained popularity for accurate prediction of fracture in ductile metallic sheets due to their ease of implementation. Accurate description of anisotropic fracture behavior is an active research field for sheet metal forming. In the present study, two isotropic ductile fracture models, i.e., modified Mohr-Coulomb and Hosford-Coulomb are evaluated for an O-tempered aluminum alloy (AA1050-O) sheet. The plastic anisotropy is modeled with a non-associated Hill48 plasticity model. In order to verify the models, experiments are conducted for a 1.2 mm thick AA1050-O sheet under various loading conditions, such as uniaxial tension, in-plane shear, and plane strain tension at room temperature. For evaluating the anisotropic ductile fracture, tensile tests are carried out in 15° intervals to the rolling direction using digital image correlation technique. The predicted fracture limit strains by the two uncoupled fracture models are compared with experimental results to evaluate the accuracy of these models.
Research on the evolving yielding behaviour and micro-mechanism in biaxial deformation of DP1180 sheet based on crystal plasticity finite element model
Authors: Zhou Bingying , Han Fei , Wu Xiangdong , Wan Min 
Published: June 2023

Abstract
Dual-phase steels (DP steels) consist of ferrite and hard martensitic phase. For the high strength and good formability, they are widely used in automotive applications. Compared with the DP steels with lower strength, DP1180 is more special for the volume fraction of martensite is higher than that of ferrite. In this paper, the evolving plastic yielding behaviours and insight into their microscale mechanisms of DP1180 were studied by biaxial tension experiments and crystal plasticity finite element method. The representative volume element (RVE) model of DP1180 taking the dual phase fraction, grain size and texture into consideration is established and the relevant parameters of crystal plasticity are reverse calibrated by the uniaxial tensile test stress strain curve. The simulated biaxial tension tests were conducted by the established RVE model to investigate the yielding micro-mechanisms of DP1180 steel, and the obtained yield loci matches well with the test results. The simulation results show that the texture has a significant effect on the contours of the yield loci. The soft ferrite grains weaken the kinetic constraints to the polycrystalline matrix and further free the rotation and plastic deformation of the neighbouring grains. This study thus provides a comprehensive understanding of the effect of the microstructure (crystal structure, texture and dual phase fraction) on the yielding behaviour of DP1180 steel as well as a method of virtual experiment to get the yield loci of metallic materials.
An artificial neural network approach on crystal plasticity for material modelling in macroscopic simulations
Authors: Martinitz L , Hartmann C 
Published: June 2023

Abstract
Anisotropy plays a significant role in engineering, especially in the field of sheet metal forming. This particular characteristic stems mainly from the crystallographic structure of the metals and the influence of the rolling process, inducing preferred orientations of the grains. In this context, the crystal plasticity theory plays an important role as it accounts for the anisotropic nature of the elastic tensor and the orientation dependencies of the crystallographic deformation mechanisms. Despite the advantages and capabilities, the integration of the crystal plasticity theory in macro simulations is hindered by high computational costs. A novel approach aims to rectify this problem through the application of machine learning. Therefore, this work investigates the machine learning of crystal plasticity simulations, whereby the DAMASK simulation kit package is used both as a benchmark for quality and costs as well as for providing a data basis for the training and testing of the neural networks. A phenomenological material model for an AA5083 aluminium alloy provides the training data for a neural network study, testing different input parameters as well as network setups.
Prediction of texture-induced plastic anisotropy in AA6014-T4 aluminium sheets utilising two different crystal plasticity-based constitutive models
Authors: Wessel A , Perdahcioğlu E S , Butz A , van den Boogaard T , Volk W 
Published: June 2023

Abstract
Two crystal plasticity-based constitutive models that differ with respect to the flow rule (rate-dependent/rate-independent) and hardening law (phenomenological/physical-based), among other aspects, are compared with each other. To this end, both crystal plasticity-based constitutive models were deployed within a finite element framework to predict the texture-induced plastic anisotropy of an AA6014-T4 aluminium alloy considering uniaxial loading at 0°, 15°, 30°, 45°, 60°, 75° and 90° with respect to the rolling direction. The results of the stress-strain curves, the normalised yield stresses and the r-values demonstrate that both crystal plasticity-based constitutive models provide comparable results. Also, the experimental r-values were predicted with reasonable accuracy. Differences with respect to the experimental normalised yield stresses are discussed and were most likely caused by an additional direction-dependent mechanism.
Measurement of Skid Line Formation and Formation Mechanism of Automotive Outer Panel
Authors: Kishigami Y , Minote T , Urabe M , Tamai Y , Suzuki K , Maeda M , Takahashi S 
Published: June 2023

Abstract
Appearance of an automobile is one of the appealing points to customers. Character ridgelines in outer panels such as hood and door panels play an important role to make automobiles attractive, and a sharp character ridgeline which has a ridge of a small curvature radius is much more preferred to a blunt character ridgeline. However, a skid line, a kind of appearance defect, is apt to generate along the character ridgeline in press forming of a sharp character ridgeline. Although it is well-known that skid lines are caused by inhomogeneous tension, the mechanism of skid line generation was not yet fully understood. In this study, the skid line defect is quantitatively evaluated by draw forming experiment using a newly devised die which can measure a panel shape at any time during press forming. The mechanism of skid line formation was clarified by experimental results. The results of the shape measurement suggest that the ridge shape in a panel formed on the punch ridge should move to a flat area of the punch. A wavy shape should be generated there immediately before the ridge shape is flattened at the bottom dead center of the die. Then the wavy shape should grow to a skid line through springback.
Influence of process and material parameters on the twist springback prediction of a panel
Authors: Oliveira M C , Gomes C , Neto D M , Alves J L , Menezes L F 
Published: June 2023

Abstract
Both advanced high strength steels and aluminum alloys gained increasing popularity because of the constant effort to meet the social pressure of reducing the vehicle weight while keeping their safety. The ratio between material strength and weight is much higher when compared to other materials but, the high springback after forming is one of the disadvantages of these materials, particularly when exhibiting twisting and side wall curl, which are the two most difficult types of springback to control and compensate in die engineering. This study analysis the influence of several material and numerical parameters on the prediction of the twist springback, using the Twist Die. Two processing conditions were considered: (i) blank-holder force that constrains the metal flow and (ii) a stake bead, which changes the forming conditions from draw to stretch forming, at the end of the process. The modelling of the elastoplastic behavior of the sheet materials uses a wide range of experimental data, for a DP980 steel and a 6xxx aluminum alloy. In addition to the effect of the sheet material on springback, the effect of the following parameters is also analyzed numerically: (i) friction coefficient; (ii) beads; (iii) modulus of elasticity; (iv) work hardening law and (v) yield criterion. All numerical simulations were performed with the finite element in-house code DD3IMP. The process parameter that most affects the twist springback is the presence of the stake bead, reducing significantly the springback. In addition, the reduction of the friction coefficient and of the elastic modulus also leads to an increase in springback. On the other hand, the yield criterion has little influence on springback of this component. The twist springback shows a different trend for the steel and the aluminum alloy that seems to be related with the different yield strength but also with the distinct gap between the punch and the die.
Deformation Prediction of Titanium Alloy in Incremental Sheet Forming with Anisotropic and Asymmetric Yield Function
Authors: Kim M , Park N 
Published: June 2023

Abstract
The present study is concerned with the prediction of deformation in incremental sheet forming (ISF) for a Ti6Al4V sheet. To investigate anisotropic and asymmetric behaviors, uniaxial tension and compression tests were conducted along the rolling direction (RD), diagonal direction (DD), and transverse direction (TD). A representative yield function for a HCP material, the Cazacu–Plunkett–Barlat (CPB06) yield criterion, was selected for constitutive modeling to take into account anisotropy/asymmetry-induced distortional yielding of the titanium alloy. The chord modulus degradation was confirmed through uniaxial loading–unloading tests. The ISF tests were carried out using a single contact-point tool following a truncated pyramid tool path. To predict the deformation during the ISF, finite element analyses were conducted with the ABAQUS explicit and the vectorized user-subroutine (VUMAT). The performance of various constitutive models was evaluated based on the comparison of deformed shapes and distribution of thickness from the experiment and the FEA.
Fracture toughness to assess the effect of trimming on the fatigue behaviour of high-strength steels for chassis parts
Authors: Parareda S , Frómeta D , Casellas D , Gustafsson D , Olsson E , Munier R , Mateo A 
Published: June 2023

Abstract
High-strength steels are widely used in vehicle body-in-white, offering a good balance between crashworthiness and lightweight design. The increased requirements of heavier electric vehicles, in terms of fatigue resistance and crashworthiness, highlight that chassis parts have remarkable lightweighting potential. However, applying these grades in chassis parts is not straightforward, as the forming processes, like trimming, may introduce surface defects that compromise the fatigue resistance of the component. This work presents a material selection strategy for the applicability of high-strength steels in chassis parts of electric vehicles. The proposed approach allows the evaluation of the key parameters of the chassis parts in a simple way. The crash performance is evaluated through fracture toughness using the essential work of fracture (EWF) methodology. The method is applied to thin high-strength steel sheets employing double-edge notched tensile specimens (DENT). On the other hand, fatigue performance is investigated in terms of fatigue resistance for both notched and unnotched specimens. The results for different complex-phase and dual-phase steels show a good agreement between the EWF and the fatigue notch factor. The method could help apply high-strength steel to chassis parts, as designers will have a tool to focus the expensive fatigue tests on the best material candidates.
Cruciform tension-shear test for sheet metal: Evaluation of methods for calculating plastic work
Authors: Sato S , Kim M , Ha J , Korkolis Y P , Kuwabara T 
Published: June 2023

Abstract
The tensile-shear test specimen devised by Kim et al. (Kim M, Ha J, Bonica S and Korkolis YP 2021 Proc. 13th Int. Conf. Technol. Plast. pp. 1961-1967) is used to evaluate methods for calculating the plastic work per unit volume of a metal sheet subjected to combined tension and shear. The deformation of the tensile-shear specimen is analysed using finite element analysis (FEA). In tension-shear deformation, a material element undergoes rigid body rotation as well as in-plane deformation. Therefore, methods for calculating the stress components and the incremental strain components with respect to the material coordinate system and the spatial coordinate system are discussed. It is confirmed that the plastic work per unit volume does not depend on the coordinate system adopted in the calculation as long as the same coordinate system is used to evaluate the stress components and strain increment components.
Bendability assessment of advanced high strength steels thanks to artificial neural networks
Authors: Teaca M , Dietsch P , Durrenberger L , Tihay K , Oueslati S 
Published: June 2023

Abstract
Thanks to their very important strength in addition to their considerable formability and ductility, the newly developed Advanced High Strength Steel (AHSS) allow carmakers to save mass on the vehicles they produce. However, before industrial implementation by OEMs, any grade has to be approved. The bending test defined in VDA238-100 [1] test specification is a key indicator of the material ductility and is increasingly requested in the scope of their homologation. The test consists in bending a square sample of sheet material with a knife. The sample is supported by two rolls. The aim of this test is to determine the maximum angle reachable by the sample before it breaks. We can also derive the maximum strain reachable by the material before fracture initiation. Mainly 2 different angles are defined: the angle after springback, that can be measured manually and the angle at maximum load, which is to be considered in the VDA238-100. The test specification gives instructions on the determination of the bending angle. Nevertheless, the approach is purely geometric and only relies on the parameters of the test. No influence of the tested material is taken into account. This approach can be improved because for AHSS that are very ductile and have a bending angle over 100°, the proposed formula can provide unphysical results. For this reason, the innovative proposed approach is to calculate the bending angle at maximal force and to determine the fracture strain thanks to Artificial Neural Networks, one of the most promising tools for resolution of engineering problems. This new approach considers a large panel of materials tested experimentally or numerically and significantly improves the prediction.
Dimensional precision and wear of a new approach for prototype tooling in deep drawing
Authors: Holzer K , Maier L , Böhm V , Volk W 
Published: June 2023

Abstract
In this work, we present and evaluate a new approach for prototype tooling in deep drawing based on direct polymer additive tooling. With fused filament fabrication (FFF) a PLA shell is printed additively. Afterwards, this is filled with ultra-high performance concrete (UHPC). UHPC is characterized by its higher strength properties compared to conventional concrete materials, which makes the material feasible for forming applications. Two configurations of these hybrid UHPC polymer additive are possible: either the PLA shell is in contact with the sheet metal during forming or UHPC. The hybrid UHPC polymer additive tooling approach has the potential to be more cost-efficient for small series. The dimensional precision and wear of such hybrid tools is evaluated using a standard cup geometry. A test series of 30 cups with sheet metal DX56+Z with 1 mm thickness was drawn with the hybrid tools as well as with a polymeric tool and a conventional steel tool. The dimensional precision and wear of the prototype tools was evaluated optically.
Investigation of tool damage in shear cutting of ultra-high strength sheet steels
Authors: Beier Thorsten , Iizuka Eiji , Shimmiya Toyohisa , Miyake Hiroto 
Published: June 2023

Abstract
Proportions of high- and ultra-high strength steels are constantly increasing in modern car bodies. In the press shop there are uncertainties concerning the application of steels with strength higher than 1000MPa particularly concerning shear cutting processes. To support the steel user regarding a tool material and coating and the wear behavior, long-term shear cutting test had been carried out. The effects of various shear cutting conditions on tool damage were investigated by continuous shear cutting test with an amount of cutting cuts up to 100,000 times. Tested sheet materials were 780, 1’180 and 1’470MPa grade steels. The changed cutting conditions were sheet steel strength, tool material, cutting clearance, and rake angle. Measurements by laser and confocal microscopes were carried out in order to reveal tool damage mechanisms. The features of tool damage were classified as wear, chipping, and plastic deformation. The amount of plastic deformation rises with the increase of sheet steel strength. Not only plastic deformation but also chipping in the tested tool was observed in the cutting test of 1180MPa sheet steel by standard tool steel (DIN 1.2379) after 40’000 cuts. Large plastic deformation in the tested tool was observed in a cutting test of 1470MPa sheet steel by high-speed steel (DIN 1.3343) after 100’000 cuts although no chipping was detected. Under a rake angle of 5°, serious chipping and tool wear were observed especially near the final sheet-tool contact position. Regarding clearance, the amount of plastic tool deformation increased with the decrease of the clearance. This effect of the clearance can be explained by vertical force and by sheet rotation during cutting.