Single Form Research Articles

Charge Variants Characterization of Co-Formulated Antibodies by Three-Dimensional Liquid Chromatography-Mass Spectrometry.

Co-formulated antibodies can bring clinical benefits to patients by combining two or more antibodies in a single dosage form. However, the quality analysis of co-formulated antibodies raises additional challenges, compared to individual antibodies, due to the need for accurate analysis of multiple antibodies in one solution. It is extremely difficult to effectively separate the charge variants of the two co-formulated antibodies using one ion exchange chromatography (IEC) method because of their similar characteristics. In this study, a novel method was developed for the charge variants characterization of co-formulated antibodies using three-dimensional liquid chromatography-mass spectrometry (3D-LC-MS). Hydrophobic interaction chromatography (HIC) was used as the first dimension to separate and collect the two co-formulated antibodies. The two collections were then injected into the second-dimension IEC separately for charge variants separation and analysis. Subsequently, the separated charge variants underwent on-line desalting in the third-dimension reverse-phase chromatography (RPC) and subsequent mass spectroscopy analysis. The novel method could simultaneously provide a charge variants ratio and post-translational modification (PTM) data for the two co-formulated antibodies. Therefore, it could be used for release testing and stability studies of co-formulated antibodies, making up for the shortcomings of the existing approaches. It was the first time that charge variants of co-formulated antibodies were characterized by the 3D-LC-MS method, to the best of our knowledge.

Utilization of spent bleaching earth as green filler and plasticizer in the manufacture of rubber compounds for solid tire production

This study utilized spent bleaching earth (SBE) as a single form of filler and plasticizer in the manufacture of rubber components for solid tire vulcanizate. SBE, an underutilized byproduct of vegetable oil purification, is abundantly available globally and can be used as a filler and plasticizer in rubber compounds. This aligns with environmental sustainability principles, reduces disposal costs, and lowers raw material expenses in rubber manufacturing. In this research, the SBE was applied for each formula from SBE-02 to SBE-05 at ratios of 15–30 per hundred rubber (phr). As a comparison, carbon black (CB) filler (65 phr), CaCO3 (35 phr), and plasticizer derived from petroleum in the form of paraffinic oil (PO) (6 phr) were used. Rubber components were produced by masticating natural and synthetic rubber in an open mill, followed by the addition of filler, plasticizer, accelerator, co-activator, anti-degradant, and vulcanization agent. The resulting compounds were vulcanized at 150 °C and 10 MPa for 17 minutes. The test results demonstrated that incorporating SBE at a ratio of 15 phr (SBE-02) significantly reduced the cure time (t90) to 8 minutes and 20 seconds, the shortest among all tested formulations. The mechanical properties of the SBE-02 vulcanizate rubber met the requirements for solid wheelchair tire applications, with a hardness of 70 Shore A. However, its abrasion resistance test result of 189.1 g/cm³ was the lowest among the formulations tested. Furthermore, the scorch time (ts2) of the SBE-02 was determined to be 2 minutes and 35 seconds. Results from a 1000x magnification scanning electron microscope (SEM) reveal air gaps on all sample surfaces of different sizes. The elements C, O, Zn, Si, Ca, and Pb dominate the SEM-EDX results for all rubber vulcanizate samples from all three spectra, in varying weight percentages. The identification of functional groups with FTIR on all rubber vulcanizate samples shows Si–O–Si bending at 2, 4, and 5 and Si–O–Al stretching at 3, 5 on the wave number spectrum of 680–413 cm−1 Si–O–Si on the wave number spectrum 1100–1050 cm−1 from the infrared spectrum.

Structural and magnetic insights of the novel phosphate Ca2NiFe2(PO4)4

One of the primary goals of scientists in the field of materials chemistry is to explore new functional materials, the discovery of new crystal structures and the understanding of their structure-properties relationship. This paper outlines the synthesis of a novel orthophosphate, Ca2NiFe2(PO4)4, in the single crystal and powder forms. The crystallographic analysis reveals that this newly synthesized phosphate exhibits an orthorhombic crystal lattice with the Pbca space group. The crystal structure is composed of PO4 tetrahedra connected to Fe1O6, Fe2O5 and NiO5 polyhedra through shared vertices. This interconnection forms a three-dimensional framework that encloses cavities housing Ca2+ cations. A sol-gel technique was employed to obtain the pure powder. The Rietveld refinement indicates an excellent correlation between the calculated and observed X-ray diffraction patterns. This material was further characterized structurally using infrared and Raman spectroscopy, and morphologically by scanning electron microscopy. The magnetic measurements revealed two magnetic transitions at T1∼8.9 K and T2∼16.5 K suggesting the presence of magnetic frustration with overall dominant antiferromagnetic behavior.

Ultrahigh Sensitivity for Thermographic Human-Machine Interface via Precious Metals Atomic Layer Deposition on V-MXene: Computational and Experimental Exploration.

Global healthcare based on the Internet of Things system is rapidly transforming to measure precise physiological body parameters without visiting hospitals at remote patients and associated symptoms monitoring. 2D materials and the prevailing mood of current ever-expanding MXene-based sensing devices motivate to introduce first the novel iridium (Ir) precious metal incorporated vanadium (V)-MXene via industrially favored emerging atomic layer deposition (ALD) techniques. The current work contributes a precise control and delicate balance of Ir single atomic forms or clusters on the V-MXene to constitute a unique precious metal-MXene embedded heterostructure (Ir-ALD@V-MXene) in practical real-time sensing healthcare applications to thermography with human-machine interface for the first time. Ir-ALD@V-MXene delivers an ultrahigh durability and sensing performance of 2.4%°C-1 than pristine V-MXene (0.42%°C-1), outperforming several conventionally used MXenes, graphene, underscoring the importance of the Ir-ALD innovative process. Aberration-corrected advanced ultra-high-resolution transmission/scanning transmission electron microscopy confirms the presence of Ir atomic clusters on well-aligned 2D-layered V-MXene structure and their advanced heterostructure formation (Ir-ALD@V-MXene), enhanced sensing mechanism is investigated using density functional theory (DFT) computations. A rational design empowering the Ir-ALD process on least explored V-MXene can potentially unfold further precious metals ALD-process developments for next-generation wearable personal healthcare devices.

Investigating intermediate shapes for multi-stage forming of cranial implants

Single Point Incremental Forming (SPIF), a numerically controlled sheet forming technique, excels in adaptability and cost reduction for small-scale production and customized parts. This study explores multi-stage SPIF, focusing on applications in the medical domain, particularly the fabrication of personalized medical implants. Addressing critical challenges related to formability and accuracy, this study emphasizes the significance of multi-stage forming and the importance of the design of intermediate shapes. Forming a cranial implant using one intermediate stage is studied, preliminary in pure Zinc as a cost-effective alternative for heated Ti. The intermediate shape is generated using automatic geometry adaptations such as translating and scaling the CAD model. Nine different experiments are conducted and compared in terms of final geometric accuracy and thickness distributions. The study shows that the proposed intermediate shapes for multi-stage forming significantly improve the geometric accuracy from 1.08 mm mean absolute deviation in traditional single stage forming to 0.41–0.59 mm. However, the used intermediate shapes have a strong but varying effect on thickness distributions throughout the part, showing the importance and sensitivity of the exact intermediate geometry. These insights provide a valuable understanding of the process, shaping the pathway for enhanced utilization of SPIF and setting the stage for future improvements.

Evaluation of alternate form reliability for the 9-item versions of the interprofessional socialization and valuing scale (ISVS-9A/9B)

BackgroundThe Interprofessional Socialization and Valuing Scale (ISVS) was developed to measure interprofessional socialization as one adopts and integrates learning into practice. While items for the ISVS-9A and 9B were drawn from three subscales of the original 24-item tool, these parallel forms were validated as a unidimensional measure using Canadian health professional and student populations. ObjectivesThe aim was to investigate if the ISVS-9A and ISVS-9B forms are interchangeable and examine their internal structure. DesignStudents completed an 18-question survey that included the nine items from the ISVS-9A followed by the nine items for ISVS-9B. SettingsTwo U.S. academic health science centers provided longitudinal interprofessional education (IPE) in a classroom setting. Participants625 students representing 13 programs from one institution and 512 students representing 7 health professions programs from the second institution were included in the study. MethodsParticipants completed the ISVS-9A and 9B as a single form. Intraclass correlation coefficients (ICC) and corresponding 95 % confidence intervals were calculated to measure the absolute agreement between the scores from the ISVS-9A and 9B forms. A factor analysis considering the original tool's three subscales was conducted. Results592 responses from one institution and 500 responses from the second institution were analyzed. ICC for the ISVS total scores demonstrated good reliability (0.75–0.90). However, the internal structure of the three factors demonstrated moderate reliability (0.5–0.75) and may need further investigation. ConclusionsThis study confirms the use of the ISVS-9A and 9B total score to measure interprofessional socialization in health professional students attending U.S. institutions. Additional research is needed to determine potential reasons for mixed outcomes from studies using ISVS-9A and 9B parallel forms.

The Perfluoro-o-phenylene-mercury Trimer [Hg(o-C6F4)]3 - a Textbook Example of Phase-Dependent Structural Differences.

The geometric and electronic structure of [Hg(o-C6F4)]3 (1) in the gas phase, i. e. free of intermolecular interactions, was determined by a synchronous gas-phase electron diffraction/mass spectrometry experiment (GED/MS), complemented by quantum chemical calculations. 1 is stable up to 498 K and the gas phase contains a single molecular form: the trimer [Hg(o-C6F4)]3. It has a planar structure of D3h symmetry with a Hg-C distance of 2.075(5) Å and a Hg-Hg distance of 3.614(7) Å (both rh1). Structural differences between the crystalline and gaseous state have been analyzed. Different DFT functional-basis combinations were tested, demonstrating the importance to consider the relativistic effects of the mercury atoms. The combination PBE0/MWB(Hg),cc-pVTZ(C,F) turned out to be the most appropriate for the geometry optimization of such organomercurials. The electronic structure of 1, the nature of the chemical bonding in C-Hg-C fragments and the nature of the Hg⋅⋅⋅Hg interactions have been analyzed in terms of the Natural Bond Orbital (NBO) and Quantum Theory of Atoms in Molecules (QTAIM) approaches. The influence of the nature of halogen substitution on the structure of the molecules in the series [Hg(o-C6H4)]3, [Hg(o-C6F4)]3, [Hg(o-C6Cl4)]3, [Hg(o-C6Br4)]3 was also analyzed.

Harvesting of shear piezoelectricity in a molded multicomponent crystal disc

Biomolecular piezoelectrics, such as amino acids and peptides, exhibit significant shear piezoelectric responses in single crystal form. However, naturally occurring longitudinal piezoelectricity is rare and, when present, is dampened due to the multi-directional self-assembly in polycrystalline device layers. Here we utilise cocrystallisation to engineer a multicomponent crystalline salt hydrate of S(+)Mandelic Acid and LLysine, S-Mand•L-Lys•5H2O (1). This material exhibits a predicted single crystal longitudinal piezoelectric response of d33 = 3.5 pC/N. In polycrystalline form, 1 grows as an assembly of plates which increases the measured longitudinal piezoelectricity to 11 pC/N in its macroscopic solid-state. This is due to contributions from the shear piezoelectric response d36 = 10.8 pC/N, originating from the presence of plates oriented at acute angles relative to the surface. The brittleness of the crystals (E = 37 GPa) is overcome by reinforcing the substrate-free piezoelectric disc with a thin polymer coating to prevent flaking. Structural analysis confirms that the triclinic structure of 1 gives rise to this increased response due to the relative orientations of individual crystallites. Confined crystallisation of this multi-component form with a plate-like morphology, results in macroscopic self-assembly of an amino acid cocrystal that allows for the harvesting of higher shear piezoelectricity, but in a facile longitudinal configuration.

Ultrasonic vibration-assisted single point incremental forming of hemispherical shaped component using AA3003 material

ABSTRACT Ultrasonic vibration-assisted single point incremental forming is a recent hybrid process variant of the single point incremental forming process. In this process, longitudinal ultrasonic vibration is used as an assistance in the conventional forming process. In this paper, the effect of amplitude of vibration in the ultrasonic vibration assisted single point incremental forming process have been researched. For the same, experimental work has been carried out by forming the hemispherical shaped components using multistage forming strategy. Moreover, numerical simulation work has been carried out using the LSDYNA solver and the results have been discussed in the light of depth of forming and strain distribution. The experimental fracture forming line is also developed for the AA3003 material for single point incremental forming process. High amplitude of vibration of 12 micron with 20 kHz frequency leads to poor formability; however, the lower amplitude of vibration of 8 micron with 30 kHz frequency leads to good formability.

The time course of semantic ambiguity in visual word recognition: behavioral and ERP evidence for the lexical-semantic effect.

Homonyms are words with multiple, unrelated meanings that share a single form and pronunciation. These words provide valuable insights into how semantic representation is retrieved and selected independently of orthography and phonology. This study aims to investigate the temporal dynamics of lexical and semantic processing in the visual recognition of Korean words. Specifically, we examine how homonyms and unambiguous words are processed differently during a lexical decision task (LDT) with EEG recording, considering the effects of word frequency and the number of meanings (NOMs). Participants performed a lexical decision task where they were required to determine if a visually presented stimulus was a valid Korean word. We compared the behavioral responses and event-related potentials (ERPs) evoked by homonyms and unambiguous words, each possessing either high or low word frequency. Both subjective and objective NOMs were measured and manipulated, while controlling for the subjective balance of individual frequencies of meanings to control for confounding from the relatedness of meaning (ROM). For ERP analysis, a non-parametric cluster-based permutation test was employed in addition to the two time windows of interest (i.e., N400 and P600). Behavioral results indicated a marginally significant interaction between word frequency and semantic ambiguity along with a main effect of word frequency, showing faster and more accurate responses for high-frequency words. An ambiguity advantage was observed only for low-frequency words, with no significant effect found for high-frequency words. ERP results revealed that lexical-semantic interactions were reflected in the modulations of the N400 and P600 components. High-frequency homonyms elicited an enhanced N400 amplitude, while low-frequency homonyms showed a reduced P600 amplitude. The findings suggest that the activation of semantic information occurs simultaneously with lexical processing, rather than during post-lexical or decision-making processes. Furthermore, considering balanced homonyms were employed in this study, inhibitory competition may arise from the high-frequency individual meanings of high-frequency words. In contrast, in low-frequency words, a facilitative effect may arise from gains in global semantic activation or semantic feedback to the orthographic level.

Impact of Urban Morphology on High-Density Commercial Block Energy Consumption in Severe Cold Regions

In sustainable city development, urban form plays an important role in block energy consumption, and as different environmental contexts and block functions create differences in energy use, it is necessary to study the relationship between morphology and energy consumption under the dual constraints of special environments and special block functions. Urban high-density blocks have concentrated energy consumption, high energy intensity, and complex morphological layout, but the influencing mechanism of the block’s morphology on its energy consumption remains unclear. Accordingly, this study focuses on the mechanism and evaluation method of the influence of morphology on the energy consumption of high-density commercial blocks in severe cold regions. Through Grasshopper model extraction, EnergyPlus performance simulation, Pearson correlation analysis, and linear regression analysis, this study extracts and classifies high-density commercial blocks in Harbin, China, into six basic layout types (Courtyard, Courtyard-T, Slab, Slab-T, Point, Point-T) according to their horizontal and vertical morphology, analyzes the energy consumption characteristics of each basic type, examines the relationships between energy use intensity (EUI) and building density (BD) and between floor area ratio (FAR) and building height standard deviation (BHSD), and constructs theoretical models by controlling variables to study the effect of a single form parameter on block EUI. The research findings are as follows: (1) The annual energy consumption of Point and Slab blocks is relatively low, whereas that of Courtyard and Courtyard-T blocks is higher due to the lack of open space in Courtyards and the poor ventilation in summer. (2) FAR is significantly correlated with the energy consumption of high-density commercial blocks in severe cold regions, while the effects of BD and BHSD are weaker than those of FAR. For every 0.1 increase in BD, every 1 increase in FAR, and every 1(m) increase in BHSD, the Winter Daily EUI of the Slab block changes by +0.87, −2.26, and −0.22 (kWh/m2), respectively, whereas that of the Slab-T block changes by −0.38, +0.68, and +0.08 (kWh/m2), respectively. (3) Controlling other variables, a large BD is theoretically beneficial to energy performance in the blocks, and increasing BD in the range of 0.4–0.55 has a significant effect on lowering energy consumption in Point blocks. EUI increases with the increase in FAR, while the change depends on different block types with the increase in BHSD. This study provides design strategies for high-density commercial blocks in severe cold regions. Under different layout types, though EUI shows different relationships with BD, FAR, and BHSD, Slab-T and Point-T blocks can achieve excellent energy performance by appropriately increasing BD and decreasing FAR, whereas Slab blocks need to decrease BD while increasing FAR. The patterns found in this paper can provide strategic help for policymaking and early urban design.

Lupus nephritis and thrombotic microangiopathy: A review

Lupus nephritis (LN) is one of the most common organ-specific manifestations of systemic lupus erythematosus (SLE). Various clinical signs of LN develop in at least 50% of patients with SLE. In addition to LN, the spectrum of renal lesions associated with SLE also includes vascular pathology. One of the variants of renal microvascular injury is thrombotic microangiopathy (TMA), the mechanisms of which are diverse. The review focuses on the main forms of TMA, including antiphospholipid syndrome and nephropathy associated with antiphospholipid syndrome, TMA caused by complement system regulation disorders and deficiency of ADAMTS13. In most cases, these forms of TMA are combined with LN. However, they may also exist as a single form of kidney damage. This article discusses the TMA pathogenesis, the impact on kidney prognosis, and treatment options.

The Effects of Lithium, Metformin and Everolimus Substances on Cell Growth in 2D and 3D Ishikawa Endometrial Carcinoma Cell Culture

Purpose: Our aim is to study the effects of the single and combined treatments of Everolimus, Metformin, and Lithium Chloride in two-dimensional (2D, monolayer) and three-dimensional (3D, spheroid) cell cultures of Ishikawa cells, which comprise the endometrial cancer cell line. Materials and methods: As part of the study, the effects of single and combined forms of Everolimus, Metformin, and Lithium Chloride were determined on cell viability, invasion, colony formation and apoptosis, and PI3K/AKT/mTOR pathway. Cell viability was assessed using XTT assay. CASP3, CASP8, CASP9, FASL, FADD, TNF, TRADD, BAX, P53, PI3KCA, PI3KCB, PTEN, MTOR, AKT1 genes were evaluated with RT-PCR, apoptosis was evaluated by flow cytometry and 3D spheroid results were evaluated with invert microscope analysis. Results: Everolimus, metformin, and lithium's IC50 levels were found at 48 hours to be 37.46 nM, 48.59 mM, and 100 µM, respectively. It was determined that the invasive capacities of Ishikawa cells in treatment groups, as well as cell colony formation were significantly reduced. In addition, Ishikawa spheroid cells were significantly suppressed compared with the control groups. RT-PCR results revealed that substances and their combinations affect genes associated with PI3K/AKT/mTOR pathway and apoptosis. Flow cytometry results showed notably increased apoptosis by single and combined treatments. Conclusion: As a result, the single and combination forms of everolimus, metformin, and lithium have reduced cell proliferation, induced apoptosis, and decreased mTOR activation through various mechanisms in Ishikawa cells.

Manufacture of tunnel-shaped sheet metal parts with improved accuracy using novel toolpath strategies for single point incremental forming

Manufacture of tunnel-shaped sheet metal parts with improved accuracy using novel toolpath strategies for single point incremental forming

Class Symbolic Regression: Gotta Fit ’Em All

We introduce “Class Symbolic Regression” (Class SR), the first framework for automatically finding a single analytical functional form that accurately fits multiple data sets—each realization being governed by its own (possibly) unique set of fitting parameters. This hierarchical framework leverages the common constraint that all the members of a single class of physical phenomena follow a common governing law. Our approach extends the capabilities of our earlier Physical Symbolic Optimization (Φ-SO) framework for symbolic regression, which integrates dimensional analysis constraints and deep reinforcement learning for unsupervised symbolic analytical function discovery from data. Additionally, we introduce the first Class SR benchmark, comprising a series of synthetic physical challenges specifically designed to evaluate such algorithms. We demonstrate the efficacy of our novel approach by applying it to these benchmark challenges and showcase its practical utility for astrophysics by successfully extracting an analytic galaxy potential from a set of simulated orbits approximating stellar streams.

Lower subjective social status is associated with increased adiposity and self-reported eating in the absence of hunger due to negative affect among children reporting teasing distress.

Low social standing and teasing are independently associated with increased body mass index (BMI) and overeating in children. However, children with low social status may be vulnerable to teasing. We tested the statistical interaction of subjective social status (SSS) and subjective socioeconomic status (SSES) and teasing distress on BMI, fat mass index (FMI), and eating in the absence of hunger (EAH) in children (Mage = 13.09 years, SD = 2.50 years; 27.8% overweight/obese). Multiple linear regressions identified the main effects of self-reported SSS (compared to peers in school), distress due to teasing, and their interaction on BMI (n = 115), FMI (n = 114), and child- (n = 100) and parent-reported (n = 97) EAH. Teasing distress was associated with greater BMI, FMI, and child-reported EAH due to negative affect (a subscale of EAH) and total EAH scores. There were no associations of SSS with these outcomes. However, there was an interaction between SSS and teasing distress for BMI, FMI, and EAH from negative affect such that lower SSS was associated with higher BMI, FMI, and EAH from negative affect in the presence of teasing distress. However, there were no main effects or interactions (with teasing distress) of SSES on the outcomes. These findings suggest that the relationship between lower SSS and increased adiposity and overeating behaviors may be exacerbated by other threats to social standing, such as teasing. Children exposed to multiple social threats may be more susceptible to eating beyond physiological need and obesity than those who experience a single form of perceived social disadvantage.

CGKPN: Cross-Graph Knowledge Propagation Network with Adaptive Connection for Reasoning-Based Machine Reading Comprehension

The task of machine reading comprehension (MRC) is to enable machine to read and understand a piece of text and then answer the corresponding question correctly. This task requires machine to not only be able to perform semantic understanding but also possess logical reasoning capabilities. Just like human reading, it involves thinking about the text from two interacting perspectives of semantics and logic. However, previous methods based on reading comprehension either consider only the logical structure of the text or only the semantic structure of the text and cannot simultaneously balance semantic understanding and logical reasoning. This single form of reasoning cannot make the machine fully understand the meaning of the text. Additionally, the issue of sparsity in composition presents a significant challenge for models that rely on graph-based reasoning. To this end, a cross-graph knowledge propagation network (CGKPN) with adaptive connection is presented to address the above issues. The model first performs self-view node embedding on the constructed logical graph and semantic graph to update the representations of the graphs. Specifically, a relevance matrix between nodes is introduced to adaptively adjust node connections in response to the challenge posed by sparse graph. Subsequently, CGKPN conducts cross-graph knowledge propagation on nodes that are identical in both graphs, effectively resolving conflicts arising from identical nodes in different views, and enabling the model to better integrate the logical and semantic relationships of the text through efficient interaction. Experiments on the two MRC datasets ReClor and LogiQA indicate the superior performance of our proposed model CGKPN compared to other existing baselines.

Correction: The contribution of energy systems during 30-second lower body Wingate anaerobic test in combat sports athletes: Intermittent versus single forms and gender comparison

Correction: The contribution of energy systems during 30-second lower body Wingate anaerobic test in combat sports athletes: Intermittent versus single forms and gender comparison

Ammonothermal Crystal Growth of Functional Nitrides for Semiconductor Devices: Status and Potential.

The state-of-the-art ammonothermal method for the growth of nitrides is reviewed here, with an emphasis on binary and ternary nitrides beyond GaN. A wide range of relevant aspects are covered, from fundamental autoclave technology, to reactivity and solubility of elements, to synthesized crystalline nitride materials and their properties. Initially, the potential of emerging and novel nitrides is discussed, motivating their synthesis in single crystal form. This is followed by a summary of our current understanding of the reactivity/solubility of species and the state-of-the-art single crystal synthesis for GaN, AlN, AlGaN, BN, InN, and, more generally, ternary and higher order nitrides. Investigation of the synthesized materials is presented, with a focus on point defects (impurities, native defects including hydrogenated vacancies) based on GaN and potential pathways for their mitigation or circumvention for achieving a wide range of controllable functional and structural material properties. Lastly, recent developments in autoclave technology are reviewed, based on GaN, with a focus on advances in development of in situ technologies, including in situ temperature measurements, optical absorption via UV/Vis spectroscopy, imaging of the solution and crystals via optical (visible, X-ray), along with use of X-ray computed tomography and diffraction. While time intensive to develop, these technologies are now capable of offering unprecedented insight into the autoclave and, hence, facilitating the rapid exploration of novel nitride synthesis using the ammonothermal method.

Thermo-Mechanical Numerical Simulation of Friction Stir Rotation-Assisted Single Point Incremental Forming of Commercially Pure Titanium Sheets.

Single point incremental forming (SPIF) is becoming more and more widely used in the metal industry due to its high production flexibility and the possibility of obtaining larger material deformations than during conventional sheet metal forming processes. This paper presents the results of the numerical modeling of friction stir rotation-assisted SPIF of commercially pure 0.4 mm-thick titanium sheets. The aim of this research was to build a reliable finite element-based thermo-mechanical model of the warm forming process of titanium sheets. Finite element-based simulations were conducted in Abaqus/Explicit software (version 2019). The formability of sheet metal when forming conical cones with a slope angle of 45° was analyzed. The numerical model assumes complex thermal interactions between the forming tool, the sheet metal and the surroundings. The heat generation capability was used to heat generation caused by frictional sliding. Mesh sensitivity analysis showed that a 1 mm mesh provides the best agreement with the experimental results of total forming force (prediction error 3%). It was observed that the higher the size of finite elements (2 mm and 4 mm), the greater the fluctuation of the total forming force. The maximum temperature recorded in the contact zone using the FLIR T400 infrared camera was 157 °C, while the FE-based model predicted this value with an error of 1.3%. The thinning detected by measuring the drawpiece with the ARGUS non-contact strain measuring system and predicted by the FEM model showed a uniform thickness in the drawpiece wall zone. The FE-based model overestimated the minimum and maximum wall thicknesses by 3.7 and 5.9%, respectively.