bluuebunny/crossref_metadata_2025_split huggingface dataset:
Axisymmetric V-Bending of Sheet Metal: Determining the Fracture Strain and the Weakest Material Direction for Plane Strain Tension in One Test
Authors: Beerli T , Grolleau V , Mohr D , Roth C C 
Published: May 2022

Abstract
Plane strain tension is one of the most critical loading conditions leading to ductile failure in forming and crash applications. Hence knowing the fracture strain and weakest orientation for this stress state is crucial for safe design. A novel axisymmetric V-bending experiment is proposed to identify the strain to fracture and the weakest sheet material orientation for plane strain tension under proportional loading. After clamping its inner and outer boundaries, a disc-shaped specimen with an annular gage section is bent over a tubular knife of diameter 54mm. A single camera takes images of the top surface of the specimen throughout the experiment. It allows for timely crack detection and digital image correlation-based strain measurements. Experiments are performed on a range of modern engineering materials comprising two aluminium alloys (AA7075 and AA6014) as well as two steels (DP1180 and CR4). The experiments are complemented by Finite Element simulations to assess the robustness of the novel experimental approach.
Hot tensile and expansion tests of Ductibor®1000 steel
Authors: Demazel N , Boyer A , Laurent H , Oliveira M C 
Published: May 2022

Abstract
The boron steels present high mechanical properties which are of great interest for lightening the vehicle parts. But these steels, as the Ductibor®1000, need to be hot formed. The hot stamping process consists of a heating/austenization step leading to an increase of the formability, followed by simultaneous forming and quenching steps. In order to understand the thermomechanical and metallurgical cycles occurring during this process, this study focuses on two different test devices at high temperatures using direct resistance heating: a Gleeble 3500 machine for tensile tests and a new bulge test device. The two different tests were performed on the Ductibor®1000 steel for a temperature of 900°C (with temperature holding during deformation) after an austenization step, which consists of heating up to 900°C and a temperature holding stage. The stress-strain curves of the tensile tests obtained using Digital Image Correlation (DIC) are compared to the stress-strain curves of the bulge tests obtained using a laser profilometer and the membrane theory.
A relative approach for uncertainty quantification of inversely identified material behavior using a heterogeneous test for sheet metal
Authors: Conde M , Coppieters S , Andrade-Campos A 
Published: May 2022

Abstract
The process of calibrating the material parameters of a constitutive model has inherent uncertainty sources. These can lead to inadequate material behavior characterization and, consequently, errors in the numerical simulations. A robust mechanical test is necessary for accurate material mechanical characterization. In this work, it is relatively quantified the uncertainties of the parameter identification of the Swift hardening law and the Yld2000-2d yield function using Digital Image Correlation (DIC) and a DIC-levelled approach. The levels of uncertainty are calculated with a derivative-based local method, having into consideration the Karush-Kuhn-Tucker (KKT) conditions for optimization problems. The mechanical test used for the parameter calibration was an optimized interior notched specimen that presents several strain and stress states simultaneously. The synthetic images were generated based on the numerical data, and the strain fields were accessed using DIC techniques. It was concluded that the step size is the DIC parameter that most influences the material parameter identification.
Characterization of elasto-plastic transition of sheet metal by using large-scale four-point bending test
Authors: Liegard W , Tabourot L , Balland P 
Published: May 2022

Abstract
The elastic properties of a material do play an important role in the spring back behaviour of sheet metal and have a dominant influence on the depth of where the bending tool has to go. In industry, the elastic behaviour is often approximated to a pure linear behaviour defined by two coefficients: Young’s modulus (E) and yield stress (Re). This modelling hypotheses result in geometrical errors in the angle and flange lengths of bended part. In order to better determine material behaviour at very small strains, a large-scale four-point bending test machine is presented in this study. Generating pure bending and measuring the residual radius allow observation of the transition between elastic and plastic deformation behaviour. By deforming the test beam in the supposed pure elastic area, it appears that the pure elasticity behaviour of the material is indeed non-existent. Plastic strains can be detected as soon as the very first bending of the sample, at very low equivalent stress well under usual accepted elastic yield stresses. Perspectives are addressed in order to solve this difficulty, which hinders the possibility of correctly simulating the bending process, particularly with regard to tight geometry requirements.
On the use of the Gleeble® test as a heterogeneous test: sensitivity analysis on temperature, strain and strain rate
Authors: Coelho B. , Thuillier S. 
Published: May 2022

Abstract
The development of hot and warm forming processes for the manufacture of complex-shaped alloy components has been increasing. At the same time, the knowledge of the effect of certain variables involved in such processes such as temperature and strain rate is essential for an accurate modelling of the materials and processes. This work provides a sensitivity study on the effect of different testing conditions variables on beta titanium-molybdenum (Ti-Mo) alloys. Data from quasi-static uniaxial tensile tests performed on a dog bone shaped specimen using a Gleeble® machine is post-processed with Aramis digital image correlation (DIC) software and numerical models of the tests are developed using Abaqus® finite element analysis (FEA) software. Results considering different temperature conditions, different applied strain rates and different gauge lengths for the determination of the mechanical properties of the material are discussed.
On the inverse identification methods for forming plasticity models using full-field measurements
Authors: Andrade-Campos A , Bastos N , Conde M , Gonçalves M , Henriques J , Lourenço R , Martins J M P , Oliveira M G , Prates P , Rumor L 
Published: May 2022

Abstract
The simulation of deep drawing processes and its quality is intrinsically dependent on the accuracy of the constitutive model in reproducing the mechanical behaviour of the sheet metal material. Today, the calibration of elastoplastic models – correspondent to the inverse identification of the material parameters – often uses full-field measurements, through Digital Image Correlation (DIC) techniques, to capture non-homogeneous strain fields and states, coupled with non-straightforward numerical inverse methodologies. In the last decade, new parameter identification methodologies, such as the Finite Element Model Updating (FEMU), the Constitutive Equation Gap (CEG) method, the Equilibrium Gap Method (EGM) and the Virtual Fields Method (VFM) have been developed and have proven to be effective for non-linear plasticity models. Nonetheless, the FEMU and the VFM have distinguished themselves from the others. More recently, supervised Machine Learning (ML) techniques have been also used as an inverse identification method. These artificial intelligence-based methods use large datasets of numerical tests to train an inverse model in which the input is the history of the strain field and loads during the test, and the output are directly the material parameters.
The goal of this paper is to analyse, compare and discuss these inverse identification methods, with particular focus on the FEMU, VFM, and ML methodologies. A heterogeneous tensile-load test is considered to compare in detail the FEMU, VFM, and ML strategies.
Analysis of Distributed-Ledger-Technology for the Exchange of Design, Production and Simulation Data in Roll Forming
Authors: Kohl B , Krüger M , Dietl T , Lechner M , Trunzer E , Merklein M , Sedlmaier A , Vogel-Heuser B 
Published: May 2022

Abstract
Digitalization in the metal forming industry needs to be improved to achieve the goals set by Industrie 4.0. Distributed-Ledger-Technology (DLT) has been identified as a promising foundation for tackling the underlying problem of consistent information exchange. DLT-based solutions have already been developed, but none explicitly covers the roll forming use-case. This paper presents a Hyperledger-Fabric-based blockchain network to fill this research gap. This network is specifically designed for the roll forming industry, while still aiming to meet general information exchange requirements. The roll forming use-case is divided into the material supply chain and a design/simulation workflow. Participants and parameters in these two data transfer chains have been validated with the help of industry experts. Running the conceptualized network on an on-premise server has allowed for a detailed evaluation. Feedback provided by experts of the roll forming industry shows the potential of the presented network. Furthermore, the presented solution covers requirements often neglected by existing approaches like large data handling, compatibility to existing interfaces, secure communication, and access rights definition. In summary, this paper provides a pioneering implementation and evaluation of a DLT-based solution for the roll forming industry and, therefore, a foundation for the next steps towards Industrie 4.0.
Automatic generation of 3d spiral tool path for incremental sheet metal forming of mechanical parts with complex geometry
Authors: Frikha Sirine , Giraud-Moreau Laurence , Bouguecha Anas , Haddar Mohamed 
Published: May 2022

Abstract
Incremental sheet metal forming is a flexible manufacturing technology that allows to form of various components on the same milling machine, without expensive tools. A hemispherical tool moves along a CNC-controlled tool path and deforms the sheet into the desired shape. The tool path has a significant role in the geometric accuracy of the final part. There has been very little research on the problem of the forming of sophisticated parts with asymmetric wall angles. This paper presents a new approach to generating optimized tool paths for single-point incremental sheet forming (SPIF). At first, a strategy is proposed for the automatic generation of a 3D tool path during forming in a single-step operation. Then, a systematic technique of creating intermediate shapes is investigated by defining tool paths interpolated from the final part shape. The proposed methodology is applied to form a hip cup prosthesis. This part has a complex asymmetric geometry with important angles, a multi-step approach is used. The proposed methodology to define the different tool paths was implemented in Matlab. A numerical simulation of the incremental forming process is performed to predict the final geometry of the aluminum sheet. A comparison of desired and predicted geometries shows the reliability of the proposed method.
Springback inhibition of Ti-6Al-4V sheet with impact hydroforming at room temperature
Authors: Li H , Xu Y , Chen S F , Song H W , Zhang S H 
Published: May 2022

Abstract
Springback is a tough issue in sheet forming, and always leads to dimensional inaccuracy of formed parts. Titanium alloy selected as desired light-weight alloy has been playing significant roles in aerospace industry because of its good comprehensive performance. Whereas, titanium alloy components manufactured always exhibit severe springback at room temperature, which greatly restrict their application. To explore the possibility of reducing springback, rectangular lath-shaped parts with Ti-6Al-4V alloy sheet were fabricated by impact hydroforming (IHF) with self-designed equipment. Consequently, much lower springback is obtained using IHF with high strain rate than that formed by conventional stretch-bending with low strain rate. Great efforts are paid to clarify the mechanism of springback restriction under IHF. Different from traditional forming methods, more complex and high-speed interaction behavior between liquid and Ti-6Al-4V alloy sheet occurs. It considerably increases the difficulty for analyzing the deformation process of sheet under IHF. Thus, a novel solid-liquid coupling numerical simulation technology for IHF was developed. To validate the simulation accuracy, experiments with different forming processes and parameters were performed. Given the combined analysis of experimental and simulation results, it is found that distinctive forming paths are introduced between stretch-bending and IHF. Specifically, the preferred deformation region of sheet transfers from middle region for conventional stretch-bending to end regions under IHF, which mainly attributes to the unique loading behavior of liquid at high strain rate.
Understanding the influence of servo-press kinematics on a sheet metal forming process using a simulation-based approach
Authors: Burlat M , Maillard A 
Published: May 2022

Abstract
The capabilities offered by the servo-presses are not fully exploited by the sheet metal forming companies due to the lack of knowledge of their influence on the forming processes. Indeed, the control of the beneficial effects and the full use of servo-press features, such as the programmable kinematics, are increasingly becoming concerns for the companies having acquired that type of press. In this context, the finite element simulation is undoubtedly an approach to evaluate the potential gains generated by those presses and to validate the servo-press kinematics.
This study is an attempt to gain insight into the impact of servo-press kinematics on a sheet metal forming feasibility. The forming experiments presented in this study have been carried out by CETIM for a X2CrNi18-09 stainless steel. The numerical simulation has been performed with AutoForm software that enables the user to rapidly and accurately design and simulate the sheet metal forming processes, including stamping operations. All parameters influencing the stamping operation in a servo-press can be considered. They include, for example, press kinematics, sheet temperature variation during the forming process and of course material mechanical properties. The hardening curves of the studied stainless steel at different strain rates and different temperatures have been taken into account. The simulation has been carried out for two servo-press kinematics: sinusoidal and soft-touch. The feasibility criterion, i.e. the part drawing depth, has been defined to match the experimental results. The numerical simulation with AutoForm made it possible to highlight the thermal effects, in particular, the maximum temperatures reached during the drawing operation. The simulation results analysis allowed the user to optimize the motion curve of the press in order to have a minimum cycle time while respecting the lowest possible temperature the sheet might reach during a drawing operation. Thanks to this study, the sheet metal forming companies will therefore benefit from this technology to develop and optimize the servo-presses usage.
A novel incremental sheet metal forming process for long and open section profiles
Authors: Essa A , Abeyrathna B , Rolfe B , Weiss M 
Published: May 2022

Abstract
Complex components from High Strength Steel (HSS) can be formed with Flexible Roll Forming (FRF). However, flange wrinkling limits the part shape complexity that can be achieved and hence limits its application in the automotive industry. A novel forming technology is introduced in this study, Incremental Shape Rolling (ISR), where a pre-cut blank is clamped between a top and bottom die and then a single forming tool incrementally forms the material according to the bottom die’s geometry. It is believed that ISR can significantly reduce the wrinkling issue compared to FRF. In the contrast to the incremental sheet forming process, ISR allows the manufacture of long and open sections from HSS sheets. In this work, the experimental prototyping trials of the ISR process are performed using a 5-axis milling machine and then are used to validate the FEA model which is developed to simulate and analyse the deformation behaviour of the ISR process. The results show a clear development of transverse tensile strain along the flange which can overcome the wrinkling issue when the ISR process is applied to complex profiles.
Evaluation of testing methods for the characterization of material properties under plane strain
Authors: Lenzen M , Merklein M 
Published: May 2022

Abstract
With the first numerically calculated forming simulations of a complex component by Hora in 1987, a renewed need emerged for a large number of stress-based material parameters for the yield locus modelling. Material characterization and modelling under plane strain is an important step towards an improved mapping accuracy in numerical calculated sheet metal forming processes. There are numerous of different testing methods, which can be used for this purpose. It is crucial to choose the right experiment depending on which material properties or characteristic values are needed. The aim of this investigation is to analyze the suitability of the currently mostly used testing methods that induce a plane strain in the material, the notched tensile test, the biaxial tensile test and the hydraulic bulge test with an elliptical die. For this purpose, the stress-based material properties of DC06 in all three tests are determined and compared. Subsequently, recommendations for material characterization are derived depending on the application.
Comparative study of certain substituted ions in hydroxyapatite: characterization and effect on cell viability
Authors: Korowash Sara Ibrahim , Abo-Almaged Hanan Hassan , Ibrahim Doreya M. 
Published: May 2022

Abstract
Hydroxyapatite (HA) is a biomaterial that has been widely studied for uses such as bone grafting and tissue engineering. Pure and hydroxyapatite nanoparticles with cationic (Na, Ti, and Li) as well as anionic (

CO

3

2
−

and Si4+) substitutions were synthesised using a wet chemical precipitation method followed by freeze-drying and investigated for their cytotoxicity effect. Inductively coupled plasma (ICP), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy were used to characterise the produced powders. The production of the HA phase was confirmed in all synthesised HA samples. MTT (3-(4.5-dimethylthiazol-2-yl)−2.5-diphenyl tetrazolium bromide) assay was performed using the BJ1 cell line of human normal fibroblasts to investigate the cytotoxicity of the synthesised HA samples. The cytotoxicity test showed that the HA samples were biocompatible, with the greatest results coming from Li-substituted (LiHA2) and Na-substituted (NaHA) hydroxyapatite.
Microscopic investigation on blending of montmorillonite modified bitumen and reclaimed asphalt binder
Authors: Dai Min , Chen Chang-ming , Wang Zhan , Pan Wen-hao , Sun Xiao-wei , Tang Ning , Wu Li-mei 
Published: May 2022

Abstract
The performance of asphalt mixtures containing reclaimed asphalt pavement (RAP) are strongly influenced by the degree of blending between RAP and virgin bitumen. In the aim of revealing the blending interface, the present work reports an experimental investigation on the blending degree between modified bitumen and RAP (or aged bitumen). A montmorillonite-rhodamine composite modifier was prepared as a tracer, which has exclusive element and fluorescence. Using microscopic test technique, the blending process of and the crack process of RAP bitumen was observed, and the blending image of new reclaimed asphalt mixture was obtained. The interface was investigated through image processing and machine learning. Based on the results, the montmorillonite modifier slightly affected on the softening point and penetration of virgin bitumen after addition. The blending interface was engagement like gears. The optimal heating temperature range is 110 °C to 115 °C for forming a better adhesive interface between RAP and modified bitumen. Moreover, the interface transition zone thickness between RAP and modified bitumen was measured to be 4 to 8 μm.
Efficient Bayesian phase estimation via entropy-based sampling
Authors: Qiu Yuxiang , Zhuang Min , Huang Jiahao , Lee Chaohong 
Published: May 2022

Abstract
Bayesian estimation approaches, which are capable of combining the information of experimental data from different likelihood functions to achieve high precisions, have been widely used in phase estimation via introducing a controllable auxiliary phase. Here, we present a Bayesian phase estimation (BPE) algorithm with an ingenious update rule of the auxiliary phase designed via entropy-based sampling. Unlike other adaptive BPE algorithms, the auxiliary phase in our algorithm is determined only once in a pre-estimation step. With simple statistical analysis on a small batch of data, an iteration rule for the auxiliary phase is pre-established and used in all afterward updates, instead of complex calculations in every update trails. During this pre-estimation process the most informative data can be selected, which guides one to perform the BPE with much less measurement times. As the measurement times for the same amount of Bayesian updates is significantly reduced, our algorithm via entropy-based sampling can work as efficient as other adaptive BPE algorithms and shares the advantages (such as wide dynamic range and perfect noise robustness) of non-adaptive BPE algorithms. Our algorithm is of promising applications in various practical quantum sensors such as atomic clocks and quantum magnetometers.
On orthogonal bases in the Hilbert-Schmidt space of matrices
Authors: Siewert Jens 
Published: May 2022

Abstract
Decomposition of (finite-dimensional) operators in terms of orthogonal bases of matrices has been a standard method in quantum physics for decades. In recent years, it has become increasingly popular because of various methodologies applied in quantum information, such as the graph state formalism and the theory of quantum error correcting codes, but also due to the intensified research on the Bloch representation of quantum states. In this contribution we collect various interesting facts and identities that hold for finite-dimensional orthogonal matrix bases.
Citizens with Benefits
Authors: Stemplowska Zofia 
Published: May 2022

Abstract
Can states permissibly enforce mandatory participation in the provision of public goods? Usual justifications of state action here appeal to the fact that such goods are very good for people. Arthur Ripstein argues that states can compel provision of public goods, but that the best explanation of this is grounded, not in the costs and benefits of the provision to the compelled parties, but in the parties’ moral status as independent agents. I argue that Ripstein’s alternative account poses more problems than it solves. Our best hope in grounding mandatory cooperation is to do so with reference to the duties that we have to serve people’s interests, including interests in autonomy, welfare, and being respected on account of one’s moral status.