bluuebunny/crossref_metadata_2025 huggingface dataset:
The Therapeutic Application of Hydrogen in Cancer: The Potential and
Challenges
Authors: Khiji Morteza Nazari , Arghidash Faezeh , Tanha Ghazaleh Khalili , Zadeh Rasoul Hossein , Ghorbani Elnaz , Khazaei Majid , Hassanian Seyed Mahdi , Gataa Ibrahim Saeed , Lam Alfred King-Yin , Giovannetti Elisa , Ferns Gordon A. , Nazari Elham , Avan Amir
Published: April 2024

Hydrogen therapy has emerged as a possible approach for both preventing and treating cancer. Cancers
are often associated with oxidative stress and chronic inflammation. Hydrogen, with its unique physiological
functions and characteristics, exhibits antioxidant, anti-inflammatory, and anti-apoptotic properties, making
it an attractive candidate for cancer treatment. Through its ability to mitigate oxidative damage, modulate
inflammatory responses, and sustain cellular viability, hydrogen demonstrates significant potential in preventing
cancer recurrence and improving treatment outcomes. Preclinical studies have shown the efficacy of hydrogen
therapy in several cancer types, highlighting its ability to enhance the effectiveness of conventional treatments
while reducing associated side effects. Furthermore, hydrogen therapy has been found to be safe and
well-tolerated in clinical settings. Nonetheless, additional investigations are necessary to improve a comprehensive
understanding of the mechanisms underlying hydrogen's therapeutic potential and refine the administration
and dosage protocols. However, further clinical trials are still needed to explore its safety profile and capacity.
In aggregate, hydrogen therapy represents an innovative and promising treatment for several malignancies.
Aloe-emodin: Progress in Pharmacological Activity, Safety, and
Pharmaceutical Formulation Applications
Authors: Luo Haimeng , Ji Xiaoyun , Zhang Mengyu , Ren Yaoyao , Tan Rui , Jiang Hezhong , Wu Xiaoqing
Published: April 2024

Aloe-emodin (AE) is an anthraquinone derivative and a biologically active component
sourced from various plants, including Rheum palmatum L. and Aloe vera. Known chemically as
1,8-dihydroxy-3-hydroxymethyl-anthraquinone, AE has a rich history in traditional medicine and is
esteemed for its accessibility, safety, affordability, and effectiveness. AE boasts multiple biochemical
and pharmacological properties, such as strong antibacterial, antioxidant, and antitumor effects.
Despite its array of benefits, AE's identity as an anthraquinone derivative raises concerns about its
potential for liver and kidney toxicity. Nevertheless, AE is considered a promising drug candidate
due to its significant bioactivities and cost efficiency. Recent research has highlighted that nanoformulated
AE may enhance drug delivery, biocompatibility, and pharmacological benefits, offering
a novel approach to drug design. This review delves into AE's pharmacological impacts, mechanisms,
pharmacokinetics, and safety profile, incorporating insights from studies on its nanoformulations.
The goal is to outline the burgeoning research in this area and to support the ongoing development
and utilization of AE-based therapies.
Evaluation of Moringa Oleifera Leaf Extract for its In vitro Antibacterial Properties, Mechanism of Action, and In vivo Corneal Ulcer Healing Effects in Rabbits’ Eyes
Authors: Bibi Ayesha , Dhanawat Meenakshi , Aman Shahbaz , Chauhan Samrat , Chalotra Rishabh , Mujwar Somdutt , Kaur Narinder , Maivagna Chamasse Homary , Gupta Sumeet
Published: April 2024

Background:

M. oleifera is the most adapted tree species in different medicinal eco-systems
and has resilience against climate changes. This multiple-use tree provides healthy foods,
snacks, honey, and fuel. Besides this, it has immense promising applications by offering antimicrobial
and antibacterial activities for targeted uses. This validates the court of Hippocrates that let
food be the medicine and medicine be the food for which moringa qualifies.

Objective:

The objective of this study is to assess the antioxidant properties of M. oleifera, in
vitro antibacterial activity of hydro-ethanolic extract, and further investigate in vivo healing potential
of M. oleifera for corneal ulcers and in silico analysis.

Methods:

To evaluate the antioxidant and in vitro antibacterial potency of the hydro-ethanolic extract
of M. oleifera on clinically isolated multidrug-resistant strains of Staphylococcus aureus using
agar well diffusion assay. Furthermore, in vivo, healing response of M. oleifera extract was
analysed on corneal ulcers induced in rabbit eyes infected with methicillin-resistant Staphylococcus
aureus.

Results:

The M. oleifera extract exhibited exponential antioxidant activity. In-vitro antibacterial
activity was evaluated by agar well diffusion assay showing zone of inhibition ranging from 11.05
± 0.36 to 20 ± 0.40 mm at concentrations of 20, 40, 80, and 160 mg/ml, whereas, in our finding,
no zone of inhibition was observed below 20 mg/ml concentration, which indicated that there is
threshold limit below which the antibacterial activity of M. oleifera extract is not observed. Furthermore,
continuous application of 3% and 5% M. oleifera extract (eye drop) four times a day for
14 consecutive days showed a significant healing response of the eyes of rabbits with corneal ulcers.

Conclusion:

These results suggest that M. oleifera extract could be a viable alternative or in combination
could be used in existing antibacterial therapies for corneal ulcers. Additionally, there is a
possibility of commercial formulation of M. oleifera extract in the form of deliverable pharmaceutical
products; therefore, it should be explored further.
Outcomes of Total Hip Arthroplasty Performed for HIV-Associated
Osteonecrosis in China: A Retrospective Cohort Study
Authors: Li Kangpeng , Ma Rui , Zhao Rugang , Zhang Qiang
Published: April 2024

Background:

In the post-epidemic era, Acquired Immune Deficiency Syndrome (AIDS)
remains one of the most prevalent and detrimental infectious diseases worldwide. The incidence
of osteonecrosis of the femoral head (ONFH) in AIDS patients is 100 times higher than that
in healthy individuals. Although Total Hip Arthroplasty (THA) is ultimately necessary for most
patients, there is still a dearth of evidence regarding its safety and efficacy in Chinese AIDS patients.

Methods:

The clinical data of 49 patients who met the inclusion and exclusion criteria were retrospectively
analyzed. Simultaneously, we categorized patients whose hemoglobin and albumin met
a specific threshold as the optimized group and performed group comparisons.

Results:

There are statistical differences in Harris score and VAS score pre- and post-operation,
with a low overall complication rate. Notably, no disparities were observed between the optimized
group and the partial optimized group in terms of overall conditions, laboratory examination
indicators, severity of ONFH, surgical outcomes, surgical complications, pain perception or
functional limitations. Furthermore, no correlation was found between CD4+ T lymphocytes and
hemoglobin levels, albumin levels, white blood cell count, or platelet count.

Conclusion:

THA is safe and effective in Chinese AIDS patients with ONFH. However, optimal
treatment has limited efficacy in AIDS patients undergoing THA for ONFH. The reconsideration
and evaluation of the predictive value of CD4+ T lymphocytes for postoperative complications in
joint replacement procedures is warranted.
Xanthone Derivatives: A Pharmacological Panorama of Versatility
Authors: Mehra Anuradha , Sangwan Rekha , Owusu Emmanuel
Published: April 2024

Xanthones are a class of naturally occurring compounds found in various plant
sources. Over the years, studies have revealed therapeutic impending xanthones in treating and
managing several ailments, including cancer, inflammation, and microbial infections. Xanthones
exert their therapeutic effects through various mechanisms, such as anti-inflammatory, antioxidant,
and anti-proliferative activities. It has also been found that xanthones induce apoptosis, inhibit
cell proliferation, and arrest cell cycles by modulating several signaling pathways. This review
objective is to deliver an inclusive overview of the therapeutic essence of xanthones and
their potential use as a natural remedy for managing and treating various diseases.
Examining the Sensing Technology in Microfluidic Sensors with Material
for Various Microfluidic Applications: A Review
Authors: Saxena Ankur , Kakde Bhagwat , Mishra Ajay Kumar
Published: April 2024

Microfluidic sensors have garnered significant attention over the past decade due to
the growing need for microsystem automation and their applications in biology and optical control.
This review paper explores the extensive use of microfluidic applications across diverse sectors,
including medical, optical, and automation. The study examines various types of microfluidic
sensors tailored for specific applications and analyzes the materials employed in microfluidic
chips, including their respective advantages and disadvantages. Additionally, it delves into specific
microfluidic pressure sensors, elucidating their underlying principles and methods for detecting
parameters. This paper explores the concept of microfluidics sensing mechanisms with
biomedical applications, flow sensor application to measure the pressure of a fluid, thermal sensor
application to measure the cell temperature, and chemical sensor application to measure the
concentration of chemicals such as glucose and cocaine. This material is utilized to design the
sensor and fabricate the device to measure the fluid properties and effect of fluid in the channel.
The paper also explores the need for microfluidic pressure sensors in different categories of applications.
In conclusion, the research highlights the existing research gaps within the realm of
microfluidic sensors.
Breaking Down the Blockchain Architecture: Components, Characteristics
and Future Trends
Authors: Goel Aarti , Mishra Anurag , Yadav Vikash
Published: April 2024

Blockchain, the revolutionary technology behind the existence of cryptocurrencies has
received enormous recognition worldwide due to its immutable system which allows transactions
to take place in a decentralized manner ensuring security and accountability. In a trustless environment,
blockchain systems work consistently, where each block’s data is distributed across a
dense peer-to-peer (P2P) network. In this type of network, each node acts as a backup because all
transactions are stored in every node. It follows a set of validation criteria that provide transparency,
trust, and data security. Blockchain primarily works on a P2P network which is generally
more secure, prohibiting any attack or failure at a single point that might be encountered in the
case of a centralized network. All nodes present in it work in association with a consensus algorithm
to provide services in a synchronized manner, which makes the working of blockchain robust
and much more resilient.
A blockchain network is defined as the interconnection of many nodes, and each node holds a
copy of the ledger. It can be observed as a continuously growing chain of blocks, and blocks are
interconnected with the support of a hash function. Block-chain-based solutions are used in financial
services, healthcare, the Internet of Things, and so on. However, this technology holds
the potential to overcome many obstacles such as technical issues, rapid change, and lack of acceptance
on a global level that it is currently facing. This chapter deals with blockchain Architecture,
various consensus algorithms used in different blockchains, and future trends of this technology.
It also explains its key components and characteristics that would help us understand the
topic in greater depth.
Thermo-Acoustic Behaviour of K2CrO4 and K4 [Fe(CN)6] in Aqueous Dimethylformamide at Different Temperatures
Authors: Panda Rajalaxmi , Panda Subhraraj , Biswal Susanta Kumar
Published: April 2024

Introduction:

Acoustic parameters can help us understand how temperature and
concentration affect the behaviour of potassium ferrocyanide and potassium chromate electrolytes
in the aqueous solvent Dimethylformamide.

Methods:

The solution's density (ρ), viscosity (η), and ultrasonic speed (u) were measured
at various concentrations and temperatures (ranging from 293 K to 313 K) using a pycnometer,
an Ostwald viscometer, and an ultrasonic interferometer at frequencies of 1MHz,
respectively. Based on these measurements, other acoustic parameters were calculated,
such as free length (Lr), internal pressure (πi), adiabatic compressibility (β), acoustic impedance
(Z), relaxation time (τ), and Gibbs free energy (ΔG).

Results:

These acoustic and thermodynamic parameters were used to explore various interactions,
molecular motion, and interaction modes, as well as their effects, which were influenced
by the size of the pure component and the mixtures. The analysis showed that
changes in temperature and concentration led to specific parameter differences, which affected
the interactions between the solute and solvent.

Conclusions:

This study demonstrated that increasing the concentration of the mixture increased
the density, viscosity, and ultrasonic velocity due to the interaction between the
solute and solvent, indicating molecular interaction in the mixture.
Estimation of Radiation Dose Parameters of High-Resolution Computed
Tomography Chest Examination for COVID-19 Patients: A Retrospective
Study
Authors: Bhatt Mahesh Chandra , Upmanyu Arun , Bansal Subhash Chand , Dogra Ayush
Published: April 2024

Background::

During the COVID-19 pandemic, high-resolution computed tomography
chest examination was widely used to diagnose the coronavirus disease. Thus, radiation dose optimization
is an essential requirement to decrease the risk of radiation hazards.

Objective::

This study aimed to estimate the radiation dose parameters of high-resolution computed
tomography chest examination of COVID-19 patients using automatic tube current modulation technique
and compare the values with various standard diagnostic reference levels (DRLs) available in
the literature.

Materials and Methods::

It is a retrospective study conducted on 205 patients with COVID-19, including
144 males and 61 females with a median age of 49 years. All patients with clinical and positive
laboratory findings were confirmed by an RT-PCR test. The data were collected from the Department
of Radiodiagnosis Government Base Hospital Almora (Uttarakhand) from September 2020
to May 2021. All patients underwent high-resolution computed tomography chest examination with
an automatic tube current modulation technique. Radiation dose parameters, such as Volume Computed
Tomography Dose Index (CTDIvol) and Dose Length Product (DLP), were extracted from the
dose report, and Effective dose (ED) was calculated.

Results::

The mean volume computed tomography dose index, dose length product, and effective
dose were 4.36 mGy, 136.29 mGy.cm, and 1.8mSv respectively.

Conclusion::

Volume computed tomography dose index and dose length product values at the 75th
percentile were well below the various DRLs, which confirmed the usefulness of the automatic tube
current modulation technique in high-resolution computed tomography (HRCT) of the chest for dose
optimization at 120 kV.
Experimental evaluation of the maximal force before debonding a part from the build platform of an AM printer
Authors: SPITAELS L.
Published: April 2024

Abstract. Hybrid manufacturing relies on the combination of different processes to overcome their own limitations. Combining additive manufacturing such as material extrusion (MEX) and subtractive conventional processes such as milling enables the production of complex design parts with smooth surface and tight tolerances to be foreseen. However, finishing a part directly in the printer by milling operations brings new questions as the maximal force the part can withstand before debonding from the build platform. This paper proposes an experimental method to determine this force by studying the influence of several parameters: the adhesion strategy, the infill pattern and density, the zone of the part where the force is applied as well as the influence of the part design. The method was successfully tested with Polylactic Acid (PLA) parts on a standard MEX printer: the Ultimaker 2+. In the best configuration: no brim, cubic infill of 95% and a force applied on an entire part face, the parts resisted to a force of 50.59 N ± 1.97 N.
A novel method to characterize low-temperature brittle failure at various pre-strains
Authors: BECHLER Jan
Published: April 2024

Abstract. A new characterization method for the determination of the pre-strain dependent ductile-to-brittle-transition-temperature (DBTT) of steel is presented in this paper. From four different types of mild steel circular cups were deep drawn. Out of these cups, rings were cut, which were used as Charpy impact test specimens. The Charpy-notch was placed at two different positions along the circumference of the ring: due to the steel anisotropy (rolling direction) the side walls of the cup have variations in strain, hence, notches are placed at areas with high, or low level of forming pre-strains. Using the ring samples, Charpy impact tests have been carried out at various temperature levels and the absorbed energy was measured as a function of temperature. The test results have been processed into material-specific DBTT values, including the dependency of pre-strain. As a result: high pre-strains generally raise the DBTT and therefore increase the risk of brittle failure in a low-temperature impact load. The pre-strain dependency of the DBTT varies for different types of mild steels – this is likely due to differences in the chemical composition and microstructure. Interstitial free steel with a near zero amount carbon and no added boron is most sensitive to forming pre-strain. The addition of boron in general shifts the DBTT to lower temperatures and reduces the pre-strain sensitivity.
Parametric failure limit detection for the sheet metal forming of a floating photovoltaic (FPV) aluminum alloy structure
Authors: TVEIT Sigbjørn
Published: April 2024

Abstract. The sheet metal forming process of a floating photovoltaic (FPV) structure is simulated in LS-DYNA. An anisotropic yield criterion and a two-term Voce hardening law are used to model the plastic behavior of AA5083-H111 sheets. The numerical model incorporates thickness variations to trigger local necking and uses a critical thickness strain as a fracture criterion. To establish a methodology that can be expanded for further studies, the research explores the relationship between cup depth and drawbead distance by proposing an algorithm to distinguish between successful and unsuccessful sheet metal forming operations.
Insights from crystal-plasticity-based predictions on deformation of an Mg-10Gd extrudate
Authors: STEGLICH Dirk
Published: April 2024

Abstract. The mechanical behaviour of an extruded magnesium alloy was quantified in tension and compression along the extrusion direction. With the aid of EBSD measurements the material symmetry was examined, and discrete grain orientations were used to predict the multiaxial plastic behaviour along orientations perpendicular to the extrusion direction by means of the EVPSC formalism. It was found that the material is transversely isotropic, shows a small amount of distortional hardening and modest differences in hardening between the extrusion direction and the tangential direction. A phenomenological plasticity law was calibrated based on the predictions, which allowed performing the finite-element analysis of the expansion process of a vascular stent.
Measurement and analysis of the strength differential effect of 6000-series aluminum alloy sheet
Authors: AKIYAMA Kaisei
Published: April 2024

Abstract. The tension-compression asymmetry (TCA, referred to as the strength differential effect, SDE, for annealed materials) of a 1.1-mm-thick 6000-series aluminum alloy sheet, A6116-T4, which is 3-months age hardened is measured using a uniaxial tensile test and an in-plane compression test. It is found that the in-plane compressive flow stress is 1-7 % higher than the uniaxial tensile flow stress; therefore, the material exhibits the SDE. Moreover, a stacked compression test in the normal (through-thickness) direction (ND) of the test sample is also performed to measure the hydrostatic stress dependence of the yield stress. It is found that the uniaxial compressive flow stress in the ND is 4-9 % higher than the equibiaxial tensile flow stress measured using a cruciform equibiaxial tension test (ISO 16842); therefore, the hydrostatic stress dependence of the yield stress is confirmed. Hence, it is concluded that the SDE observed in A6116-T4 is caused by the hydrostatic stress dependence of the yield stress.
Plasticity experiments on heavy gauge S700 steel
Authors: COPPIETERS S.
Published: April 2024

Abstract. High Strength Steel grades are indispensable for the development of heavy-duty constructions and components with high specific strength. In these applications, a profound understanding of the plastic material behavior up to fracture is required to assess the structural integrity through numerical simulations. In this paper, we investigate the plastic behavior of S700 with a nominal thickness of 12 mm. The steel production process of a hot rolled, heavy gauge material inherently results in a through-thickness variation of the mechanical properties: i) solidification of the continuously cast slab starts from the outer surface, causing a gradient of the chemical composition across the thickness, ii) subsequent thermomechanical controlled rolling results in a variation of microstructure and texture over the thickness. To enhance the predictive accuracy of numerical simulations, we are examining the manifestation of this inhomogeneity across a range of plasticity experiments.
The experimental full-field method (EFFM) for parameter calibration applied on an anisotropic constitutive model
Authors: ILG Christian
Published: April 2024

Abstract. Accurate characterization of material models is essential to ensure a higher prediction quality in Finite Element Analysis (FEA) under general loading conditions in sheet metal forming. Achieving accurate material model data frequently involves intricate inverse analysis techniques and numerous experimental tests. To overcome the complexities associated with calibration processes, the adoption of optical measuring systems like Digital Image Correlation (DIC) is widespread in material model calibration. The rich information obtained from DIC measurements is often used by material model calibration strategies to calibrate the values of material or model parameters, such as extrapolation of stress-strain curves or Lankford parameters that are not necessarily constant over the entire range of plastic deformation. This study presents the Experimental Full-Field Method (EFFM) as an innovative iterative approach for the calibration of material properties. As a special implementation of Finite Element Model Update (FEMU) [1], the EFFM uses the whole deformation field gained from DIC as boundary conditions [2]. This is then used in an inverse optimization procedure to determine parameters of complex material models. In this research, the EFFM is applied to an anisotropic constitutive model [3] to optimize three flow curves in 0°, 45° and 90° directions w.r.t. the rolling direction and the yield surface exponent, which reflects the polycrystal structure of the sheet material, to define the shape of the evolving yield locus in stress space. This is achieved by a modified tensile test specimen with L-shaped cut-outs which allows a distribution of higher strain values over a wider range of triaxiality values. With the direct use of the experimental deformation field in the FE simulation, displacements and strains are not any more objects of the optimization but only stresses. This also eliminates the step of mapping between experiments and simulations. Moreover, by using implicit time integration the inversion of the stiffness matrix becomes redundant, as positions of all nodes are already predetermined at each time step. These aspects make EFFM faster and more accurate than conventional FEMU.
Warm forming of AA7075-T6: optimizing the heating time to maintain T6 condition
Authors: LAURENT Hervé
Published: April 2024

Abstract. Warm forming at 200°C is an interesting way of improving the formability of AA7075-T6. The T6 condition offers the highest ultimate and yield strengths of this aluminium alloy. It is therefore important to maintain these excellent mechanical properties at the end of the forming process. With the hot forming process at temperature above 450°C, it is necessary to add a heat recovery treatment obtained during paint baking to keep this T6 state, which is costly in terms of time and energy. In warm forming process, it is possible to maintain the T6 condition by controlling the heating time to avoid precipitation changes. The objective of this study is to find these optimal heating time conditions to maintain the T6 state during warm forming multi-step process. Different heating times were reproduced using a Gleeble 3500 machine. Electrical conductivity and hardness were measured after these different conditions to make the link with the evolutions of precipitates of AA7075-T6. Tensile tests were also performed to characterize the mechanical behavior at the end of these heating cycles. A holding time of less than 10 seconds is determined to maintain the T6 state at 200◦C. Two multi-step warm forming devices (a cylindrical cup in two steps and a U-channel part) were finally tested to validate these optimal time forming conditions.
Analysis of oxidized hot working tool steel tribological behavior in tube piercing
Authors: MURILLO-MARRODÁN A.
Published: April 2024

Abstract. In this paper the tribological behavior of the oxide layer present on the mandrel used in rotary piercing tube manufacturing operations has been analyzed. A hot upsetting sliding test campaign has been carried out in order to analyze the hot working steel oxide layer under different contact conditions. Optical microscopy, profilometry and XRD have been used to establish the type of contact and oxides generated, respectively. Results show abrasive sliding contact between mandrel and tube materials. Oxide transfer from the tube material to the mandrel material occurs in all the tested conditions. Regarding friction, the coefficient of friction COF is reduced by the presence of the oxide layer, confirming its lubricity. It has been observed how COF decreases with the increase of contact pressure and relative velocity. The value of COF is reduced from 0.42 to 0.18 if the contact pressure is increased from 165 to 200 MPa and the relative velocity is increased from 200 to 450 mm/s.
Effect of process parameters on friction in aluminum sheet forming
Authors: JALALI MOGHADAS Farshid
Published: April 2024

Abstract. The bending under tension (BUT) test is used to mimic aluminum sheet forming process and study the effect of friction on drawing force. Multidraw Drylube E1 was used to lubricate the samples. Experiments were designed and executed to study the effects of rolling direction, lubricant amount, roll temperature and contact pressure on the drawing force. Strain in the sample was measured using digital image correlation (DIC) technique. Real area of contact is calculated using height distribution histograms of the surface in contact. Apart from the back force, variations in drawing force results from changes in bending and unbending force and friction force. The results imply that the friction force will not necessarily increase with increasing the back force and it depends on the contact pressure.
A novel method to investigate tribological behaviors under transient temperatures using Pin-on-Cylinder tribometer and IR-thermography in glass forming
Authors: VU Anh Tuan
Published: April 2024

Abstract. In high-temperature material forming, achieving high precision demands a nuanced understanding of thermal and mechanical interactions at the contact interface. Conventional methods, often involving separate measurements of friction and heat transfer coefficients, encounter challenges as the growing number of influencing factors amplifies experimental complexity. This research introduces an innovative approach enabling the simultaneous determination of both coefficients in a single experimental run. A specially designed pin-on-cylinder tribometer enables the measurement of transient friction forces resulting from temperature variations at the interface, recorded by an infrared thermographic camera. Inverse methods are developed to derive the friction and heat transfer coefficients from the acquired transient force and temperature data. The method expedites the determination of contact coefficients, providing an efficient avenue for numerical and analytical studies in hot forming processes.
Shear cutting: Model-based prediction of material parameters based on synthetic process force signals
Authors: RIEMER Matthias
Published: April 2024

Abstract. Data-driven process monitoring is an approach in the field of forming technology for increasing process efficiency. In shear cutting processes surrogate models based on process force signals can be used for process monitoring. Currently, the data basis for developing such models has to be generated within experiments. The generation of synthetic training data using numerical methods seems to be a more efficient alternative approach. In this work, it is investigated whether virtual training data for the prediction of material properties can be generated by numerical methods. An FE model of the investigated shear cutting process has been designed and validated based on experiments. It is shown that especially the consideration of the tool stiffness has a significant influence on the simulated process force signal. The validated FE model is used to generate synthetic training data. Based on this data, different prediction models are trained to predict the material model parameters based on the force signals. Different model types are compared and the hyperparameters are optimized for the preferred model.
An experimental study of effect of printed thickness on the mechanical properties of LPBF produced AlSi10Mg
Authors: FAHIMI Pouya
Published: April 2024

Abstract. Additive manufacturing process allows fabrication of parts with a broad range of sizes with high resolution. This size variation introduces new mechanical properties within the printed component, which creates a significant challenge for the qualification of additively manufactured parts. This unresolved issue hinders the implementation of additive manufacturing in high performance engineering applications. To attain optimal performance of additive components, it is imperative to gain a comprehensive understanding of the size effect. While many studies have explored the mechanical properties and microstructure of additively manufactured AlSi10Mg, the size effect remains relatively undefined. To gain more knowledge on this matter, AlSi10Mg samples with four different thicknesses were fabricated using a selective laser melting machine and tensile tests were performed to characterize the material behavior. Stress-strain curves were derived with consideration of nominal and measured cross section and the resulting diagram showed a considerable difference for the samples with minimum thickness, which was 0.5 mm. Comparing the results between the 2 mm and 0.5 mm thick specimens demonstrated more than 50 percent decrease in tensile properties including ultimate tensile strength and elongation at fracture. Also, the study of strain rate indicated no significant strain rate sensitivity for either thickness. These findings contribute to better understanding the size effects on behavior of printed AlSi10Mg, promoting further commercial adoption of this material.
Sensor integration for process control in deep drawing
Authors: JUNG Robert Oliver
Published: April 2024

Abstract. In the context of increasing resource efficiency and profitability, deep drawing can be improved using a digital twin and closed-loop process control. Cyber-physical production systems (CPPS) enable data capture and analysis for an autonomous optimization of the manufacturing process. In this work reference sensor signals are used to control the force and material flow with hydraulic actuators between the blank holder and the die. A novel model-based optimization method is proposed to determine the best sensor location, allowing for standardized evaluation and reduced integration time. FE simulations and forming trials are conducted for validation. The findings indicate time and resource savings through an efficient sensor implementation in deep drawing tools for process control.
Material-data-driven prediction of sheared surface tears of fine blanked parts
Authors: ORTJOHANN Lucia
Published: April 2024

Abstract. Fine blanking is a cost-effective manufacturing technology for mass-producing sheet-metal components with high sheared surface quality. For steels with higher carbon content, the quality of fine blanking products is significantly influenced by microstructural characteristics, such as the morphology and distribution of carbides, which can be controlled through heat treatment [1]. Precisely, there is a relationship between spheroidization of carbides and the occurrence of tears at the sheared surface of fine blanked parts especially at the tip of a gear [2]. Furthermore, material characteristics can vary both along a sheet-metal coil and from coil to coil despite tight tolerances [3] leading to unpredictable tearing. To monitor the fluctuation of material characteristics at regular intervals along sheet-metal, non-destructive testing (NDT) is used before the process providing information about the microstructure. While in the state of the art, the data from NDT was used to calculate the mechanical properties and to optimize the process based on these properties [4], in this paper, NDT data is used to predict the sheared surface tears of fine blanked parts, without the reduction of the content-rich data to mechanical properties. For this purpose, an experiment was conducted on the fine blanking of the steel 42CrMo4+A to produce components resembling a gear shape. Prior to the manufacturing process, the material was measured using an eddy current sensor, and subsequently the tearing of the fine blanked parts was evaluated. For the prediction of sheared surface tears, linear regression methods were used, and a feature selection was done to find the excitation frequencies of the eddy current sensor with the highest impact on the tearing. It was shown that the eddy current measurements along the coil contain valuable information about the tearing of the fine blanked part.
Improving the flow forming process by a novel closed-loop control
Authors: KERSTING L.
Published: April 2024

Abstract. The incremental flow forming process is currently enhanced in research context by special closed-loop property control concepts to increase the productivity and to control the product properties making invisible property structures like a magnetic barcode possible. However, it is preferred to establish property control concepts on single roller machines instead of conventional machines with three roller actuation due to the better machine accessibility. For those single roller machines, rather poor surface qualities of flow formed workpieces were observed in the past especially for hydraulic actuators. Thus, a new actuator closed-loop position control concept is developed in this paper using model-based control design methods and taking the flow forming forces as a load into account. The novel closed-loop control is validated during workpiece production at the actual single roller flow forming machine. An analysis of the manufactured workpieces show that the surface quality is significantly enhanced by the new control to a roughness level almost similar to conventional three roller flow forming. Thus, a sincere added value to the flow forming process is offered by the novel actuator closed-loop position control.
Predicting fine blanking process signals from sheet metal thickness
Authors: MOON Jiyoung
Published: April 2024

Abstract. In sheet metal forming and blanking processes, the direct assessment of process conditions and product quality poses a challenge due to high production rates and the inaccessibility of the tool. In this context, the process signals generated by the manufacturing process, such as force and acoustic emissions, have the potential to serve as a valuable source of information, containing important insights into the quality of the final product as well as the complexity of the process itself. To date, it is not yet fully understood how these process signals depend on different influencing factors, such as process parameters. However, knowing how process signals, which reflect the process state, change with influencing factors is relevant to put observed signals into context and make informed decisions with respect to parameter adjustments. Conditional generative AI models, such as conditional generative adversarial networks (CGANs) offer a promising approach to the aforementioned issue by generating probable process signals based on specified conditions. In this study, thin metal sheets with three different thicknesses were provided into a fine blanking process, and corresponding punching force signals were measured. With these signals, a conditional-deep convolutional GAN (C-DCGAN), a model that combines the principles of both CGAN and deep convolutional GAN (DCGAN), is trained with sheet metal thickness specified as a condition. The trained generator is employed to predict process signals for different sheet thickness values. The presented model is evaluated with respect to thickness values that were known during training time as well as with thickness values that were not presented to the model during training.
Neural network-based estimation and compensation of friction for enhanced deep drawing process control
Authors: THIERY Sebastian
Published: April 2024

Abstract. Fluctuating process conditions, such as lubrication, can disturb the production process and lead to faulty components that have cracks or wrinkles. Real-time identification of process parameters can detect deviations in sheet forming operations and enable the process parameters to be adjusted. To increase process robustness, closed-loop control is often used to monitor and influence the material draw-in, which corresponds to the material flow and can be measured by camera systems inside the deep-drawing press. The aim of this work is to develop a control concept that can predict the optimum blank holder force by estimating the coefficient of friction based on the material draw-in of the last stroke. Using a cross-die geometry, it is shown how the material draw-in can be determined experimentally by means of a camera system and numerically by FE simulations. Finally, artificial neural network-based models are trained through simulations and are subsequently tested on a numerical case study in which the coefficient of friction is changed as a disturbance variable and must be compensated for. The widely applicable control concept has the potential to incorporate additional softsensors, for example to determine material properties, and other target variables, such as the punch force, into the optimization algorithm.
Study on the effects of tool design and process parameters on the robustness of deep drawing
Authors: HEINZEL Christine
Published: April 2024

Abstract. In metal forming manufacturing processes, parameter fluctuations and an incomplete understanding of the process can lead to an undesirable deviation of the product properties from the required specifications and, therefore, affect the robustness of the process. In deep drawing, defects such as cracks and wrinkling can be linked to uncertainties within the process- and tool design parameters. To investigate the combined effects of these parameters on the quality of the finished product, simulation models are used to study the effects of parameter changes on the product quality. With the purpose of studying the effects of significant process and tool design parameters on the deep drawing process, a numerical parameter study is carried out based on a modular tool which allows for an investigation of process parameter variations within an adjustable parameter range of tool radii. While the material draw-in and the maximum punch force are used as quality indicators of the deep-drawing process, it could be shown that the elongation of the absolute length of the finished part can be used as an additional indicator for material thinning when observing the effects of the punch shoulder and die shoulder radii on the process robustness.
Spindle speed effect on the ISF processing of materials with different thermal conductivities
Authors: QIN Zhenyuan
Published: April 2024

Abstract. Incremental sheet forming (ISF) is an advanced forming technology with high flexibility and excellent adaptability. However, conventional ISF encounters challenges in processing of hard-to-deformed materials at room temperature. To address this problem, friction stir incremental forming (FSIF) has been introduced to improve material formability at high temperatures. The aim of this work is to investigate the spindle speed effect on the forming quality for materials with different thermal conductivities by using an experimental and FE simulation. The experimental results presented the combined effect of spindle speed and conductivity on the springback and surface finish of AA1050 and CP Ti Grade 1. A good agreement was obtained in the temperature increase and distribution from experimental testing and FE simulation.
Numerical investigation of rotational friction welding for C22.8 - 41Cr4 joints using a substitute model
Authors: MOHNFELD Norman
Published: April 2024

Abstract. Rotational friction welding (RFW) is a solid-state joining process that enables the joining of similar and dissimilar materials such as metal-metal or metal-ceramic joints. Due to its high application flexibility, this process has great potential for the production of hybrid components. In order to be able to realise this potential for the production of hybrid components, the development of an improved process design is required. Due to the complexity of the process, the Finite Element Method (FEM) can be used to solve complex problems and is therefore an established tool for the design of joining processes. This work focuses on the development of an FE model to represent the RFW process of C22.8 and 41Cr4 joints. The material data required for the numerical representation of the RFW were obtained from isothermal cylinder compression tests. The frictional heat which is generated during RFW is calculated using a substitute model, which mainly depends on the Y-factor. The Y-factor indicates what percentage of the calculated frictional energy is introduced into the process. The Y-factor was determined and then verified using experimental data. A general validity of the determined Y-factors with changed process parameters could not be achieved.
In-situ CT of the clinching process – Influence of settling effects due to process interruptions
Authors: Köhler D.
Published: April 2024

Abstract. In lightweight constructions, clinching represents a cost-effective solution, in which joints are produced by local cold forming of the joining parts. Clinching phenomena are typically evaluated using destructive testing methods. While these methods influence the clinch point’s state, in-situ computed tomography (in-situ CT) is able to explore the clinching process with a specimen under load. Here, the path-controlled clinching process is interrupted at certain displacement levels and the specimen is scanned by CT while remaining in a stationary state. These interruptions are always accompanied by settling effects reducing the reaction force. Therefore, in this work, the influence of these interruptions on the force-displacement behavior during clinching and on the final clinch point’s geometric properties is investigated.
Flexible self-pierce riveting and clinching with a single joining system using the same unified joining tools
Authors: Uhe B.
Published: April 2024

Abstract. Self-pierce riveting and clinching are well-established joining techniques in car body manufacturing. For these two techniques C-frames with drives, which are mounted on industrial robots, are used to realise the joining process. Punch, die and blank holder, which build the joining tools, are characteristic for the mentioned techniques. Even though the joining tools of self-pierce riveting and clinching are similar, joining with the same unified tools is not implemented in car body manufacturing until now. Within this paper, the challenges and requirements of joining with unified joining tools are described. At the beginning of the examination, reference joints are produced experimentally with conventional joining tools. After that, unified joining tools are elaborated, using numerical simulation. At the end, the feasibility of the approach is demonstrated by experimental joining tests with the newly elaborated joining tools.
Development of new strategies for the mechanical joining of components made of aluminum die casting
Authors: KRAUS Christian
Published: April 2024

Abstract. Structures made of aluminum die casting are being used in increasing quantities as well as component sizes for various applications. Due to the size of the components, heat treatment of the cast parts following the casting process is omitted in order to meet dimensional accuracy requirements and reduce production costs. From such an approach, challenges arise with regard to the mechanical joining of these aluminum die-cast structures. On one hand, the absence of heat treatment results in a general decrease in ductility. On the other hand, the increasing size of the components introduces process-related tolerances regarding the quality of the casting, including the presence of air or gas inclusions, and significant variations in ductility within the component. These factors present challenges for mechanical joining technologies, such as the potential risk of crack-related defects during the joining process. For the robust mechanical joining of such materials, the development and validation of suitable joining strategies for aluminum die cast components is presented in this paper. A preparatory step involving localized heat treatment in the joining area is implemented to enhance the suitability of the casting material for mechanical joining. The objective is to generate an improved ductility state in the aluminum die casting material, enabling crack-free joining through self-pierce riveting. Additionally, the formability of the aluminum die casting material is characterized using a specially developed ductility testing method. This allows the prediction of potential crack-related defects during mechanical joining. The methods described are developed using the AlSi10MnMg material in its as-cast state and applied to the self-pierce riveting process.
Experimental investigation of heterogeneous mechanical tests
Authors: GONÇALVES M.
Published: April 2024

Abstract. The virtualization of sheet metal forming processes requires a precise numerical model with an accurate description of the material behavior that is classically obtained by carrying out quasi-homogeneous mechanical tests. However, several alternatives to this time-consuming task are under study. Heterogeneous tests can provide a large quantity of mechanical information in a single experiment and, therefore, their potential needs to be investigated. This work aims to present an advanced mechanical test designed by topology optimization under experimental investigation. A numerical design methodology is described, leading to a specimen geometry that is subjected experimentally to uniaxial tensile loading up to rupture. A dual-phase DP600 steel is used. During the test, the strain field is extracted from the specimen surface using a stereo digital image correlation system, and the richness of the mechanical information is further analyzed.