The “321” prefabricated highway steel truss bridge is widely used for highway rescue, disaster relief, and emergency traffic. This paper uses a 33 m double-row monolayer “321” prefabricated highway steel truss bridge to analyze its mechanical properties and component stability. The actual traffic flow capacity of a total weight of 53.32 tons is used in this study. The results show that the maximum internal force in the truss chord (including the stiffening chord) occurs in the middle span section when a centrally distributed load is applied. Meanwhile, the maximum internal force of truss diagonal members and truss vertical bars appears at the fulcrum section. Under the eccentrically distributed load, the maximum internal forces of truss chords (including stiffening chords) appear in the middle span section, which is closest to the vehicle load, while the maximum internal forces of truss diagonal members and truss vertical bars appear in the fulcrum section, which is closest to the vehicle load. While the maximum internal forces under the eccentrically distributed load are greater than the maximum internal forces under the centered-layout load, under the vehicle load, truss chords (including stiffening chords) are prone to buckling instability, and the buckling mode is mainly reverse out-of-plane buckling. The inclined members of the truss are prone to buckling instability, and the buckling mode is mainly the combination of out-of-plane bending and two-way out-of-plane bending. Truss vertical bars have good stability and are not easy to buckle. The main conclusions of this paper can provide references for the optimal design and operation safety of prefabricated highway steel truss bridges. Full article

The resolution of conventional optical microscopy is restricted by the diffraction limit. Light waves containing higher-frequency information about the sample are bound to the sample surface and cannot be collected by far-field optical microscopy. To break the resolution limit, researchers have proposed various far-field super-resolution (SR) microscopy imaging methods using evanescent waves to transfer the high-frequency information of samples to the low-frequency passband of optical microscopy. Optimization algorithms are developed to reconstruct a SR image of the sample by utilizing the high-frequency information. These techniques can be collectively referred to as spatial-frequency-shift (SFS) SR microscopy. This review aims to summarize the basic principle of SR microscopy using evanescent illumination and introduce the advances in this research area. Some current challenges and possible directions are also discussed. Full article

The management of urban flood disasters is a systematic engineering project that requires a great amount of manpower, material resources, and financial resources, and the interaction and coordination degrees of various elements in the system deeply affect the efficiency of the final governance. According to the theories of synergy, composite systems, and sustainable development, this research first established an evaluation index system to determine the synergy degree of urban flood disaster emergency management from the four dimensions of prevention and preparation, monitoring and early warning, response and rescue, and recovery and reconstruction. Then, the synergy degree was explored by using the developed composite system synergy degree model on the basis of the panel data of 18 prefecture-level cities in Henan Province from 2013 to 2021, and synergy level change characteristics were analyzed from the perspectives of time and space. Finally, the obstacle degree model was applied to explore the obstacle factors affecting synergy degree development. The results showed that the overall level of the urban flood disaster emergency management coordination degree in Henan Province was relatively low, and there were significant differences in synergy among cities. Among them, 12 cities presented mild synergy, and 6 cities showed mild nonsynergy. The spatial correlation of the synergy degree was not stable, which revealed a lack of mature coordination mechanisms for flood disaster emergency management among cities. The analysis of obstacle factors showed that recovery and reconstruction subsystems were the main obstacle systems that affected the synergy degree. Full article

Cucumbers are a popular vegetable consumed worldwide and are known for their nutritional value, containing carbohydrates, antioxidants, vitamin C, etc. The abundance of a high moisture content is correlated to cucumber perishability, which encourages investigation into ways to maintain its quality and increase shelf-life. This study was carried out to determine the effect of a moringa oil–beeswax coating on the quality of fresh cucumber at different storage temperatures for 27 days of storage. Freshly harvested cucumbers were divided into two groups: the first group was coated with the moringa oil–beeswax edible coating, while the other one was not coated (control). Each group was divided into three other subgroups, for storage at 4, 10, and 22 °C. Different quality parameters, including weight loss, color change, firmness, total soluble solid (TSS), vitamin C, and pH, were evaluated. The findings showed that the weight loss of cucumber was highly increased in non-coated samples stored at high temperature. After 27 days of storage, the highest and lowest weight reduction % were recorded for non-coated cucumbers stored at 22 °C (38.09%) and moringa oil–beeswax-coated cucumbers stored at 10 °C (12.35%), respectively. Color analysis revealed that coating had a significant impact on color values, with distinct patterns in lightness, redness-greenness, and yellowness values for both treatments at various temperatures and days. The lightness values showed minimal fluctuations and stabilized at 13.65 at both 4 °C and 10 °C. Temperature and coating had a significant impact on pH levels, with the coating potentially exhibiting a protective effect on pH stability, particularly at lower temperatures (4 °C). Additionally, both groups’ total acidity levels held steady over time and at various temperatures, with the coating having a highly significant effect on total acidity levels. The amount of vitamin C varied significantly with temperature and storage period, but the coating did not affect vitamin C content. At 22 °C, there were notable variations in the vitamin C content over the storage period, with a final value of 37.7 mg/L on coated samples. Temperature and the duration of storage (p < 0.05) had a significant impact on the levels of total soluble solids (TSS), whereas firmness values changed significantly over the storage period only. Moringa oil–beeswax edible coating has the potential to preserve the nutritional value and quality attributes of cucumber. Full article

For the past two decades, researchers have been exploring the potential benefits of combining shape-memory polymers (SMP) with carbon nanotubes (CNT). By incorporating CNT as reinforcement in SMP, they have aimed to enhance the mechanical properties and improve shape fixity. However, the remarkable intrinsic properties of CNT have also opened up new paths for actuation mechanisms, including electro- and photo-thermal responses. This opens up possibilities for developing soft actuators that could lead to technological advancements in areas such as tissue engineering and soft robotics. SMP/CNT composites offer numerous advantages, including fast actuation, remote control, performance in challenging environments, complex shape deformations, and multifunctionality. This review provides an in-depth overview of the research conducted over the past few years on the production of SMP/CNT composites with both thermoset and thermoplastic matrices, with a focus on the unique contributions of CNT to the nanocomposite’s response to external stimuli. Full article

This study leverages the efficacy of Voronoi diagram theory within a mixed-methods approach to thoroughly examine the spatial distribution, service coverage, and optimal locations for expanding electric vehicle (EV) charging infrastructure in Bangkok. Drawing on data from field surveys and public data providers, our analysis unfolds in four key stages. Firstly, we delve into the spatial distribution of charging stations, scrutinizing density, proximity to various road types, and land use through the lens of Voronoi diagrams. Secondly, the application of Voronoi diagrams informs the evaluation of service boundaries. Thirdly, utilizing this effective tool, we assess population density per parking slot or charging head to anticipate future EV adoption. Finally, the study introduces an approach to identify suitable locations for new charging stations through the application of overlapping Voronoi circles. Findings reveal a clustered distribution of charging stations along roads, particularly in the central business district, showcasing the efficiency of Voronoi diagrams in spatial analysis. Residential areas and urban commercial zones also host significant charging station concentrations. Notably, service coverage in inner Bangkok surpasses that of middle and outer areas, highlighting underserved regions. Prospective areas for new charging stations, identified through Voronoi analysis, include Bang Khae, Phra Khanong, Min Buri, and Huai Khwang. This research, rooted in the application of Voronoi diagram theory, offers vital insights for various stakeholders involved in urban infrastructure planning. By employing Voronoi diagrams within Geographic Information Systems (GIS), the study contributes to strategically placing charging stations, optimizing spatial understanding, and enhancing resource allocation. This GIS-based approach not only supports the rise of electric vehicles but also promotes sustainable urban development practices through the efficient utilization of spatial data and analysis techniques. Full article

Currently, SARS-CoV-2 has evolved into various variants, including the numerous highly mutated Omicron sub-lineages, significantly increasing immune evasion ability. The development raises concerns about the possibly diminished effectiveness of available vaccines and antibody-based therapeutics. Here, we describe those representative categories of broadly neutralizing antibodies (bnAbs) that retain prominent effectiveness against emerging variants including Omicron sub-lineages. The molecular characteristics, epitope conservation, and resistance mechanisms of these antibodies are further detailed, aiming to offer suggestion or direction for the development of therapeutic antibodies, and facilitate the design of vaccines with broad-spectrum potential. Full article

Understanding the dynamics of volcanic activity is crucial for volcano observatories in their efforts to forecast volcanic hazards. Satellite imager data hold promise in offering crucial insights into the thermal behavior of active volcanoes worldwide, facilitating the assessment of volcanic activity levels and identifying significant changes during periods of volcano unrest. The Moderate Resolution Imaging Spectroradiometer (MODIS) sensor, aboard NASA’s Terra and Aqua satellites, provides invaluable data with high temporal and spectral resolution, enabling comprehensive thermal monitoring of eruptive activity. The accuracy of volcanic activity characterization depends on the quality of models used to relate the relationship between volcanic phenomena and target variables such as temperature. Under these circumstances, machine learning (ML) techniques such as decision trees can be employed to develop reliable models without necessarily offering any particular or explicit insights. Here, we present a ML approach for quantifying volcanic thermal activity levels in near real time using thermal infrared satellite data. We develop an unsupervised Isolation Forest machine learning algorithm, fully implemented in Google Colab using Google Earth Engine (GEE) which utilizes MODIS Land Surface Temperature (LST) data to automatically retrieve information on the thermal state of volcanoes. We evaluate the algorithm on various volcanoes worldwide characterized by different levels of volcanic activity. Full article

Khat leaves, indigenous to eastern Africa, have been chewed for centuries for their stimulant effects, attributed to alkaloids such as cathinone and cathine. Although associated with gastric disorders like gastritis and gastro-oesophageal reflux disease, the underlying molecular mechanisms remain unclear. This study aimed to examine the morpho-anatomy of khat leaves using light microscopy and histochemistry and to assess the effects of leaf extracts and alkaloids on human gastric epithelial cells (GES-1). The study identified specific cells in the palisade–spongy transition zone as storage sites for psychoactive alkaloids. Leaf extracts were prepared by mimicking the chewing process, including a prolonged salivary phase followed by a gastric phase. Cytotoxicity and cell viability were evaluated using LDH and MTT assays, respectively. Additionally, the impact on IL-8 secretion, a key chemokine in gastric inflammation, was analysed under normal and TNF-α-stimulated conditions. The results showed no increase in cytotoxicity up to 250 µg/mL. However, there was a significant decrease in cell metabolism and a reduction in both basal and TNF-α-induced IL-8 secretion, but cathinone and cathine were inactive. These findings suggest that khat may not directly cause the gastric issues reported in the literature, which would rather be attributed to other confounding factors, highlighting the need for further research to clarify its biological impacts. Full article

Oscillating Water Column (OWC) systems harness wave energy using a partially submerged chamber with an underwater opening. The Savonius turbine, a vertical-axis wind turbine, is well-suited for this purpose due to its efficiency at low speeds and self-starting capability, making it an ideal power take-off (PTO) mechanism in OWC systems. This study tested an OWC device with a Savonius turbine in an air duct to evaluate its performance under varying flow directions and loads. An innovative aspect was assessing the influence of power augmenters (PAs) positioned upstream and downstream of the turbine. The experimental setup included load cells, Pitot tubes, differential pressure sensors and rotational speed sensors. Data obtained were used to calculate pressure differentials across the turbine and torque. The primary goal of using PA is to increase the C_P–λ curve area without modifying the turbine geometry, potentially enabling interventions on existing turbines without rotor dismantling. Additionally, another novelty is the implementation of a regression Machine-Learning algorithm based on decision trees to analyze the influence of various features on predicting pressure differences, thereby broadening the scope for further testing beyond physical experimentation. Full article

This paper proposes a new toggle-style negative stiffness viscous damper (TNVD), and evaluates the performance of the TNVD with the displacement amplification factor (f_d) and the energy dissipation factor (f_E). Firstly, the composition and characteristics of the TNVD are introduced. Subsequently, the displacement amplification factor is introduced to evaluate the displacement amplification ability of the TNVD, and it is decomposed into a geometric amplification factor and an effective displacement coefficient. Then, based on the geometric amplification factor and effective displacement coefficient, the correlation between the TNVD’s displacement amplification ability and inter-story deformation is studied, and an improved TNVD is proposed. By the comparison of the finite element calculation results, it is found that the improved TNVD can utilize the assumption of small structural deformation. After that, the impacts of plentiful aspects, such as the length of the lower connecting rod, the horizontal inclination angle of the lower connecting rod, the inter-story deformation limit, the cross-sectional area of the connecting rod, the damping coefficient, and the negative stiffness on the f_d and f_E of the improved TNVD, are expounded. The research results show that when the length of the TNVD’s lower connecting rod remains unchanged, the f_d and f_E present a trend of increasing first and then decreasing with the increase in the horizontal inclination angle of the lower connecting rod. When the inter-story deformation is fixed, there exists an optimal lower connecting rod’s length that satisfies a specific relationship to achieve the optimal geometric amplification factor of the TNVD. By adjusting the damping parameters of the TNVD, we can obtain a better effective displacement coefficient greater than 0.95 in the proposed target region. Meanwhile, the f_d and f_E increase with the decrease in the negative stiffness. An optimization strategy for the improved TNVD has been proposed to ensure that the TNVD has the characteristics of operational safety, ideal displacement amplification capability, and energy dissipation capability. Furthermore, a multi-objective control design method with an additional improved TNVD structure is proposed. The vibration reduction effect of the structure with the improved TNVD and the effectiveness of the optimization strategy are verified through examples. Full article

Research on evaluating sustainable transport policies is predominantly focused on their urban effects, often overlooking similar challenges in suburban and rural mobility. Therefore, the development of regionally integrated sustainable transport strategies becomes essential to comprehensively address these concerns. This study aims to bridge this gap by introducing a GIS-supported methodology that combines multiple linear regressions with hazard ratio models to quantify and map the impacts of environmentally driven regional transport policies on air pollution and human health. The main findings of an illustrative case study highlighted the importance of stronger efforts to promote the transition to shared and active transport and address the articulation between urban and rural mobility. This study offers a novel contribution to transport researchers and policymakers by proposing a methodology that (1) forecasts the impacts of regional transport policies using open data and software, ensuring its applicability for diverse regional settings, (2) provides the results in quantitative and visual formats, facilitating output analysis and visualisation and, consequently, decision-making and public consultation on proposed sustainable transport policies, and (3) sets the groundwork for including future transport-related dimensions. Full article

Estrogen (17β-estradiol) deficiency post-menopause alters bone homeostasis whereby bone resorption by osteoclasts exceeds bone formation by osteoblasts, leading to osteoporosis in females. We established an in vitro model to examine the consequences of estrogen withdrawal (E2-WD) on osteoclasts derived from the mouse macrophage RAW 264.7 cell line and utilized it to investigate the mechanism behind the enhanced osteoclast activity post-menopause. We found that a greater population of osteoclasts that underwent E2-WD contained a podosome belt necessary for osteoclasts to adhere and resorb bone and possessed elevated resorptive activity compared to osteoclasts exposed to estrogen (E2) continuously. Our results show that compared to osteoclasts that received E2 continuously, those that underwent E2-WD had a faster rate of microtubule (MT) growth, reduced RhoA activation, and shorter podosome lifespan. Thus, altered podosome and MT dynamics induced by the withdrawal of estrogen supports podosome belt assembly/stability in osteoclasts, which may explain their enhanced bone resorption activity. Full article

With the worldwide awareness of sustainability, biomass-derived carbon electrode materials for supercapacitors have attracted growing attention. In this research, for the first time, we explored the feasibility of making use of the carbon byproduct from hydrothermal liquefaction (HTL) of microalgae, termed herein as algae-derived carbon (ADC), to prepare sustainable carbon electrode materials for high-performance supercapacitor development. Specifically, we investigated carbon activation with a variety of activating reagents as well as N- and Fe-doping of the obtained ADC with the intention to enhance its electrochemical performance. We characterized the structure of the activated and doped ADCs using scanning electron microscope (SEM), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and BET surface area and pore analysis, and correlated the ADCs’ structure with their electrochemical performance as evaluated using cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), impedance, and cycle stability through an assembled symmetric two-electrode cell with 1 M H₂SO₄ as electrolyte. It was found that the ADC that is activated using KOH (KOH-ADC) showed the best electrochemical performance, and its specific capacitance was 14.1-fold larger with respect to that of the raw ADC and reached 234.5 F/g in the GCD test at a current density of 0.5 A/g. The KOH-ADC also demonstrated excellent capacitance retention (97% after 10,000 cycles at a high current density of 10 A/g) for stable long-term operations. This research pointed out a promising direction to develop sustainable electrode materials for supercapacitors from the carbon byproduct produced after HTL processing of algae. Full article

AMELX mutations cause X-linked amelogenesis imperfecta (AI), known as AI types IE, IIB, and IIC in Witkop’s classification, characterized by hypoplastic (reduced thickness) and/or hypomaturation (reduced hardness) enamel defects. In this study, we conducted whole exome analyses to unravel the disease-causing mutations for six AI families. Splicing assays, immunoblotting, and quantitative RT-PCR were conducted to investigate the molecular and cellular effects of the mutations. Four AMELX pathogenic variants (NM_182680.1:c.2T>C; c.29T>C; c.77del; c.145-1G>A) and a whole gene deletion (NG_012494.2:g.307534_403773del) were identified. The affected individuals exhibited enamel malformations, ranging from thin, poorly mineralized enamel with a “snow-capped” appearance to severe hypoplastic defects with minimal enamel. The c.145-1G>A mutation caused a -1 frameshift (NP_001133.1:p.Val35Cysfs*5). Overexpression of c.2T>C and c.29T>C AMELX demonstrated that mutant amelogenin proteins failed to be secreted, causing elevated endoplasmic reticulum stress and potential cell apoptosis. This study reveals a genotype–phenotype relationship for AMELX-associated AI: While amorphic mutations, including large deletions and 5′ truncations, of AMELX cause hypoplastic-hypomaturation enamel with snow-capped teeth (AI types IIB and IIC) due to a complete loss of gene function, neomorphic variants, including signal peptide defects and 3′ truncations, lead to severe hypoplastic/aplastic enamel (AI type IE) probably caused by “toxic” cellular effects of the mutant proteins. Full article

Fresh (raw, non-dried) walnuts (kernel moisture > 17%) have unique sensory and nutritional attributes but a narrow time availability due to their rapid deterioration during storage. In the present study, the storage (1 °C, 90% RH) potential of fresh walnuts for 20 and 40 days was assessed in relation to cultivar (Chandler, Hartley, Ioli) and the form of exposure to storage (shelled or in-shell). The effect of low-temperature exposure (at 1 °C for 0, 10 and 20 days) before nut drying was also examined. Fresh walnuts from different cultivars showed diverse quality (size, color) and physiological (respiration, weight loss) traits. Using a very low storage temperature (1 °C) was feasible to store fresh walnuts marginally up to 40 days without losing the ‘fresh’ character. The form of in-shell storage compared with shelled ones helped to determine the retention of kernel moisture and had a mild protective role in the prevention of kernel browning. The storage of fresh walnuts at 1 °C resulted in increased total phenolics (TP, by 26% in average) and antioxidant capacity (by 46%, in average) of the kernels, supporting the improvement of nutritional value due to low temperatures. The dried kernels after this short cold storage showed increased TP levels by 35–40% in comparison with conventional dried ones. Therefore, the 10 d cold exposure could be proposed as a sustainable step for incorporation in the regular postharvest handling chain for the natural enrichment of fresh and dried kernels in antioxidants. Full article

Chronic medical conditions (i.e., chronic widespread pain) may contribute to accelerated/accentuated aging, such that middle-aged individuals with comorbidities may actually show increased declines in physical, cognitive, and mental health compared to normal aging adults. We examined perceived stress, life stressors, and depression in adults with and without fibromyalgia, a chronic pain condition. Ninety-four participants (52% with fibromyalgia, 78% female) aged 50 to 93 were administered the Perceived Stress Scale, Social Readjustment Rating Scale, and Beck Depression Inventory. Hierarchical regression analyses were conducted: the predictor variables were age, gender, fibromyalgia status, depression, and fibromyalgia–depression interaction. The interaction term significantly predicted perceived stress, but not life stressors. Depression significantly predicted stress for Social Readjustment Rating Scale measures after controlling for covariates. Significant associations were found between perceived stress and life stressors in all participants. In addition, those with fibromyalgia were significantly more likely to report higher levels of stress above standardized scores on both the Perceived Stress Scale and the Social Readjustment Rating Scale. Finally, depressive symptoms played a more significant role than fibromyalgia status in predicting life stressors. Conclusions: These findings emphasize the importance of assessing different types of stress and stressors in individuals with chronic widespread pain and/or depression in mid-life and beyond to better treat individuals with these conditions. Full article

With the increasing implementation of sustainable development strategies, recycled concrete (RC) has garnered attention in research circles due to its substantial environmental and economic advantages. The presence and properties of various interface transition zones (ITZs) in RC play a vital role in its mechanical properties. This research uses a combination of multiphase inclusion theory and finite element numerical simulation to investigate and compare the impact of ITZs on concrete’s mechanical properties. The multiphase inclusion theory offers a theoretical framework for understanding ITZ behavior in concrete, categorizing it into new mortar, old mortar, new ITZ, old ITZ, and natural aggregate based on meso-structure. With simplified RC at the mesoscale, the study accurately predicts the mechanical properties of RC by adjusting the elastic modulus, Poisson’s ratio, and thickness of new and old ITZ models. Through finite element simulation and theoretical validation, the study achieves a minimal error of 6.24% in predicting the elastic modulus and 1.75% in predicting Poisson’s ratio. These results highlight the effectiveness of multiphase inclusion theory in capturing the meso-structure characteristics of RC and forecasting its macroscopic mechanical behavior while comprehensively considering the complexity of ITZs. Full article

Background and Objectives: This study aimed to determine the relationship between non-simultaneous contralateral hip fractures, urban and rural differences, fracture localization, time between fractures, physiotherapy applications, comorbidity, and the second fracture outcomes. Materials and Methods: We retrospectively analyzed 107 patients aged 65 and older with proximal femur fractures (PFFs) who underwent surgery at Düzce University Medical Faculty between January 2010 and December 2022. High-energy fractures, pathological fractures, and patients with a history of old fractures were excluded. Results: The study included 66 females (61.7%) and 41 males (38.3%), with a mean age of 83.76 years. The mean interval between two fractures was 28.3 months. There was no statistical difference between the localization of the first and second fractures (p = 0.107). However, there was a significant difference in the first PFF localizations of patients living in rural areas (p = 0.023). Patients with heart failure, respiratory failure, osteoporosis, and cognitive impairment had shorter intervals between fractures (p < 0.001). Conclusions: This study shows that age, female gender, place of residence, comorbid diseases, and whether physical therapy is received after the first fracture are significant risk factors for a second hip fracture in patients over 65 years of age. Full article

For orthogonal frequency division multiplexing (OFDM) systems in high-mobility scenarios, the estimation of time-varying multipath channels not only has a large error, which affects system performance, but also requires plenty of pilots, resulting in low spectral efficiency. To address these issues, we propose a time-varying multipath channel estimation method based on distributed compressed sensing and a multi-symbol complex exponential basis expansion model (MS-CE-BEM) by exploiting the temporal correlation and the joint delay sparsity of wideband wireless channels within the duration of multiple OFDM symbols. Furthermore, in the proposed method, a sparse pilot pattern with the self-cancellation of pilot intercarrier interference (ICI) is adopted to reduce the input parameter error of the MS-CE-BEM, and a symmetrical extension technique is introduced to reduce the modeling error. Simulation results show that, compared with existing methods, this proposed method has superior performances in channel estimation and spectrum utilization for sparse time-varying channels. Full article

Neurocognitive disorders (NCDs) are progressive conditions that severely impact cognitive function and daily living. Understanding the transition from mild to major NCD is crucial for personalized early intervention and effective management. Predictive models incorporating demographic variables, clinical data, and scores on neuropsychological and emotional tests can significantly enhance early detection and intervention strategies in primary healthcare settings. We aimed to develop and validate predictive models for the progression from mild NCD to major NCD using demographic, clinical, and neuropsychological data from 132 participants over a two-year period. Generalized Estimating Equations were employed for data analysis. Our final model achieved an accuracy of 83.7%. A higher body mass index and alcohol drinking increased the risk of progression from mild NCD to major NCD, while female sex, higher praxis abilities, and a higher score on the Geriatric Depression Scale reduced the risk. Here, we show that integrating multiple factors—ones that can be easily examined in clinical settings—into predictive models can improve early diagnosis of major NCD. This approach could facilitate timely interventions, potentially mitigating the progression of cognitive decline and improving patient outcomes in primary healthcare settings. Further research should focus on validating these models across diverse populations and exploring their implementation in various clinical contexts. Full article

This study investigates multiple cyclic loading scenarios of non-oriented electrical steel sheets through both experimental and numerical approaches. The numerical simulations were conducted using Representative Volume Elements generated with DRAGen. DRAGen allowed for the generation of Representative Volume Elements with a non-cubic shape to cover the complete sheet thickness and enough grains to represent the material’s texture. The experimental results, on the other hand, are utilized to calibrate and validate a prediction model, highlighting the significance of accumulated plastic slip as a suitable parameter correlated with fatigue life. Using the accumulated plastic slip from the simulations, a fatigue fracture locus is introduced, which describes a 3D surface dependent on the maximum stress, fatigue life, and the fatigue stress ratio. The study shows reliable results for the fatigue life prediction using the calibrated fatigue fracture locus. While substantial progress has been made in predicting the fatigue life at multiple fatigue stress ratios, notable disparities between experimental and simulation results suggest the need for further investigations regarding the influence of the surface quality. This observation motivates ongoing research efforts aimed at refining simulation methodologies to better incorporate surface roughness effects. In summary, this study presents a validated model for predicting fatigue life in non-oriented electrical steel sheets, offering valuable insights into material behavior at different loading scenarios and informing future research directions for enhanced structural performance and durability. Full article