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This study delves into the manufacturing strategies employed for fabricating tensile samples utilized in the mechanical characterization of material extrusion (MEX) components constructed with polyaryletherketone (PAEK) for aerospace applications. Two distinct methods were investigated for obtaining tensile test samples: direct cutting and extraction from a box. These methods were examined under both as-printed and annealing conditions. Quasistatic tensile tests were conducted along the building direction to evaluate the impact of processing conditions on the adhesion of overlying layers. The results unveiled significant disparities in mechanical behavior and crystallinity between directly printed samples and those derived from the box. The Young's modulus exhibited marginal influence; however, the tensile strength of directly printed samples measured at 30 MPa (prior to annealing), corresponding to 50% of the strength observed in samples cut from the box (60 MPa). Moreover, the elongation at rupture of directly printed samples was found to be less than 2%, while that of cut samples exceeded 8%. Notably, directly printed samples exhibited a significant degree of incipient crystallization (12.18%), contrasting with the lower level of crystallinity observed in samples cut from the box (3.27%). These findings underscore the importance of recognizing the limitations associated with direct sample printing, emphasizing its crucial role in accurately characterizing components destined for the aerospace industry. Furthermore, this understanding is pivotal for optimizing the performance and reliability of MEX-printed PAEK components in aerospace engineering applications. [ABSTRACT FROM AUTHOR]

In this research, a smart manufacturing approach was used to enhance the mechanical properties of aluminum (Al) for lightweight applications. The smart manufacturing involved cryomilling of Al powders with and without 5 wt.% magnesium (Mg) powders for varying durations followed by a high-pressure cold spray (HPCS) additive manufacturing process to prepare bulk components. The morphological changes, crystallite size, and composition of the cryomilled powders and cold sprayed (CS'ed) components were examined using scanning electron microscopy (SEM), x-ray diffraction (XRD), and transmission electron microscopy (TEM) techniques. The results showed that the crystallite size reduces with an increase in cryomilling time and the addition of Mg dopant. To test the mechanical properties of the bulk CS'ed components, microhardness tests were performed using a Vickers microhardness tester. Uniaxial tensile tests were also carried out to ascertain the material's tensile properties. The mechanical testing results showed great improvement in the hardness and tensile strength of CS'ed Al–Mg samples as compared to pure Al samples. Subsequently, fractography analysis of the tensile failed samples was carried out to determine the nature of the failure. The research article also discusses the inherent mechanisms for the improvement in mechanical properties of smart manufactured components as a result of Mg doping and cryomilling. [ABSTRACT FROM AUTHOR]

Highlights The off‐axis creep behavior of glass‐fiber reinforced polymer (GFRP) unidirectional lamina is crucial for engineering structural applications. A unified prediction model for time‐dependent off‐axis and on‐axis tensile creep strain in GFRP lamina is developed. The model, analogous in form to the one‐parameter plasticity model, accounts for off‐axis creep deformation separately for elastic and plastic response stages, incorporating a correction term to describe on‐axis creep deformation. The accuracy of the model is confirmed through tensile creep tests on unidirectional lamina at angles of 0, 15, 30, 45, 60, and 90 degrees. The model successfully predicts of creep deformation in the elastic and plastic response stages, respectively. The effects of creep stress, creep time, and off‐axis angle on the creep behavior are investigated. The optimal test angles for predicting off‐axis creep behavior using only two off‐axis angles' creep tests are analyzed. The dominant factors of creep behavior at various off‐axis angles are evaluated. The findings of the study include recommendations for lay‐up configuration and engineering applications of GFRP composites. A unified creep strain prediction model for GFRP lamina was developed. Creep strain was calculated separately in elastic and plastic response stages. The link between stress, time, angle and creep behavior was determined. The optimal test angles for predicting off‐axis creep behavior were evaluated. [ABSTRACT FROM AUTHOR]

This study investigates the microstructural behavior of laboratory-produced Al–Mg–Si(X)–Mn aluminum alloys, focusing on the influence of varying Si content during biaxial hot tensile testing. Alloys with Si contents of 0.7%, 0.9%, and 1.3% were subjected to biaxial deformation at temperatures of 200 °C, 300 °C, and 400 °C. Using digital image correlation analysis, the impact of Si content on microstructural evolution under biaxial tensile loading was analyzed. Force–displacement analysis revealed a consistent inverse relationship between temperature and the maximum force required to initiate strain. At the temperature of 200 °C, the Al–Mg–Si(1.3)–Mn alloy required a maximum force of 1500 N, while at the temperature of 400 °C this force decreased to 900 N. The degree of anisotropy varied, with higher Si alloys exhibiting increased resistance to deformation in the transverse direction. In particular, the Al–Mg–Si(1.3)–Mn alloy showed pronounced strain anisotropy, with large major true strain φ1 values reaching up to 0.32 at 400 °C, compared to 0.26 at 300 °C and 0.2 at 200 °C. Microstructural analysis using electron backscatter diffraction (EBSD) and energy dispersive X-ray spectrometry (EDS) showed minimal changes at low temperatures, while increased dislocation density and grain boundary distortion were observed at elevated temperatures. The β-Mg2Si precipitates, influenced by Si content and temperature, significantly affected the mechanical properties. In the Al–Mg–Si(0.7)–Mn alloy, precipitates were predominantly 1–3 µm in diameter, whereas in the Al–Mg–Si(1.3)–Mn alloy, precipitates grew to 4–8 µm at higher Si content. These findings provide critical insights into the mechanical response and deformation mechanisms of aluminum alloys under biaxial tensile conditions, essential for optimizing material performance in engineering applications. [ABSTRACT FROM AUTHOR]

Type I main‐chain polyrotaxanes (PRs) with multiple wheels threaded onto the axle are widely employed to design slide‐ring materials. However, Type II main‐chain PRs with axles threading into the macrocycles on the polymer backbones have rarely been studied, although they feature special topological structures and dynamic characteristics. Herein, we report the design and preparation of Type II main‐chain PR‐based mechanically interlocked networks (PRMINs), based on which the relationship between microscopic motion of mechanical bonds on the PRs and macroscopic mechanical performance of materials has been revealed. The representative PRMIN‐2 exhibits a robust feature in tensile tests with high stretchability (1680 %) and toughness (47.5 MJ/m3). Moreover, it also has good puncture performance with puncture energy of 22.0 mJ. Detailed rheological measurements and coarse‐grained molecular dynamics (CGMD) simulation reveal that the embedded multiple [2]rotaxane mechanical bonds on the PR backbones of PRMINs could undergo a synergistic long‐range sliding motion under external force, with the introduction of collective dangling chains into the network. As a result, the synchronized motions of coherent PR chains can be readily activated to accommodate network deformation and efficiently dissipate energy, thereby leading to enhanced mechanical performances of PRMINs. [ABSTRACT FROM AUTHOR]

Multi‐bolted composite laminates are popular in various fields. Under different working conditions, it is a serious problem to produce different kinds and extent of damage at the joints. Real‐time monitoring of it is a challenging task. The objective of this artical is to use ultrafiltration membrane/buckypaper sensor to monitor the health status of the structure at different positions in the tensile environment. Firstly, the aperture ratio is selected by tensile test, and the feasibility of ultrafiltration membrane/buckypaper sensor to monitor the bolt structure and the different response degree to different strains are verified. Then, ultrafiltration membrane/buckypaper sensor layout position is designed, and the signal response of the sensor at different positions is analyzed. The damage degree and form of different bolts are visualized by ΔR/R0 change, and the SEM scanning diagram is used for auxiliary verification. The results show that The sensor can monitor the damage condition and damage form at different positions of the double bolt structure laminate in real time. Based on this method, it can be used to study the damage behavior of more complex multi‐bolt structure under tensile environment. Highlights: Ultrafiltration membrane/buckypaper sensor was prepared by a simple and efficient process.The pore structure of the ultrafiltration membrane integrates the sensor with the double bolt structure.Monitor the different damage forms of double bolt structure caused by external load.Monitor the different degrees of strain and crack propagation stage of the double bolt structure. [ABSTRACT FROM AUTHOR]

In this work, Ti‐6Al‐4V alloy was joined by tungsten inert gas (TIG) welding and the plates were undergone through optical microscopy test, elemental study, tensile test, hardness test, and fractographic observation. Plate‐A, with low value of current input, possesses α + β bimodal structure at BM, acicular martensite at HAZ, and Widmanstätten structure with a low amount of martensite at the WZ. Plate‐B, with comparatively higher value of current during welding, possesses similar structure at the BM. The HAZ area was comparatively lesser with significant martensite formation, and the WZ contains considerable formation of Widmanstätten structure. The elemental composition of BM and WZ was established by EDS. The stress‐strain curves for both plates show that plate‐B has almost 3%, 8%, and 7% greater UTS, YS, and elongation, respectively, than plate‐A. The significant formation of Widmanstätten structure has made the WZ of plate‐B more ductile and tough, although the fractography analysis of both the plates has shown macrodimples and flowing sign of metal as indicators of good ductility. [ABSTRACT FROM AUTHOR]

In the present study, three fillers produced with carbon fiber powder (CFP) and rare earth elements were developed for low‐density polyethylene production. These fillers included CFP with a grain size of less than 400 microns and over 90% pure lanthanum and cerium oxides. Polyethylene was employed to ensure the thermoplasticity and homogeneity of the fillers. The fillers were mixed with the matrix material separately, first mechanically and then homogenously in the extruder, then the test bars were produced with an injection machine. In the mechanical tests, it was determined that the tensile strength of the test bars improved by ~20% and the elastic region increased due to the increasing amount of filler. Similarly, an improvement of about 40% in bending stress was realized. In addition, as the fluidity of the mixtures has improved, it has been possible to produce at lower temperatures and save energy in the production. Thermogravimetric analysis was conducted to determine the melting/crystallization temperatures and material losses in the compounds. The scanning electron microscope analysis showed that the fillers were irregularly distributed on the surface in parallel and perpendicular directions. In addition, x‐ray diffraction and energy dispersive spectroscopy analyses were performed on the surfaces. [ABSTRACT FROM AUTHOR]

Biological and mechanical mismatches between engineered scaffolds and native tissues poses widespread challenges for tissue restoration. Native‐like anisotropy is a critical characteristic for functional tissue replacements, yet it is an often‐overlooked aspect when designing new scaffolds. In this study, fiber‐reinforced tubular scaffolds are developed, mimicking the anisotropic characteristics of natural tissues, using native‐like silk fibroin. To predict the mechanical behavior of these innovative scaffolds, a mathematical model is employed, utilizing the properties of the scaffolds’ constituent materials, and experimentally validated through tensile testing. This approach addresses significant challenges in the design of new scaffold implants by enabling to efficiently predict the performance of several configurations, narrowing down the experimental research space. The proposed platform constitutes an appealing tool for the development of clinically relevant tissue‐equivalents. [ABSTRACT FROM AUTHOR]

Highlights Additive manufacturing for polylactic acid (PLA) reinforced with cellulose nanofibrils (CNF) could unlock fabrication of specialized and user‐specific biomedical devices. However, the process of combining PLA and CNF is challenging and proves complicated with possible irreversible CNF agglomeration and organic solvents leftover, particularly when involving solvent‐casting technique. Direct melt‐blending can mitigate these issues, but there are few reports of a single‐step melting and extrusion process to produce ready‐to‐use 3D printing filaments. This study compares the distribution of CNF fillers within the PLA matrix in PLA/CNF composites made by direct melt‐blending into filaments using a benchtop filament maker, and by solvent‐casting followed by extrusion into filaments. The filaments were 3D‐printed via fused deposition modeling (FDM), followed by tensile testing, morphology, and other characterizations. Uneven filament diameters were observed for the composite filaments prepared via solvent‐casting because of severe agglomeration, resulted in poor printability and tensile properties of filaments and 3D‐printed samples. Direct melt‐blended filament diameters were consistent, resulted in only slight decrease of tensile properties compared to pure PLA, contributing to the highest maximum tensile strength of 3D‐printed sample of 51.47 ± 1.73 MPa at 5% CNF loading. Morphology revealed good integration of CNF into PLA matrix starting at 3% CNF loading. Direct melt‐blending was comparable to the conventional methods, which enables simpler PLA/CNF composite preparation especially for 3D printing. Better dispersibility achieved by direct melt‐blending than by solvent‐casting. PLA/CNF filaments produced via solvent‐casting suffered severe agglomeration. Direct melt‐blended PLA/CNF5% yielded the highest maximum tensile strength. Morphology reveals good CNF‐PLA integration starting at 3% of CNF loading. Worsened agglomeration causing increased number of voids observed at 10% CNF. [ABSTRACT FROM AUTHOR]

ABSTRACT Bioplastics offer biodegradability and reduced environmental impact but often use nondegradable synthetic dyes. This study introduces a novel application of glow discharge plasma (GDP) technology to modify cassava starch‐based bioplastic sheets, specifically optimizing conditions to enhance their hydrophilicity and adhesion for natural dyes. This research systematically tailors plasma treatment parameters to maximize the interaction between bioplastics and eco‐friendly natural dyes. Optimal conditions, identified as 30 W for 3 min using oxygen, air, and nitrogen plasma treatments, demonstrate significant advancement in sustainable material development. Analyses (ATR‐FTIR, EDX, XPS) showed increased concentration of polar functional groups and oxygen content, with FE‐SEM and water contact angle measurements revealing improved surface roughness and wettability, respectively. Oxygen plasma treatment yielded the highest hydrophilicity and crystallinity of the polymer. Tensile tests indicated increased strength and decreased elongation. UV‐Vis spectroscopy confirmed enhanced dye retention and reduced leaching. This study demonstrates GDP's potential to incorporate eco‐friendly natural dyes into bioplastics, thereby contributing to the development of more sustainable materials. [ABSTRACT FROM AUTHOR]

The selection of an appropriate fabric for technical applications, such as protective masks, hinges on a thorough understanding of the fabric's physical and mechanical properties. This study addresses the challenge of selecting the optimal material structure for the upper layer of a protective mask, aiming to ensure adequate breathability while providing effective filtration against airborne particles and contaminants. We assessed and compared the physical–mechanical properties of five polymer spun-bond nonwoven fabrics from different suppliers. Our comprehensive evaluation included, as follows: a visual inspection; light permeability analysis; mass and thickness measurements; elongation and tensile strength tests; breathing resistance assessments; and filter penetration tests with paraffin oil. The results revealed significant variations in performance among the samples, with one fabric consistently outperforming the others across multiple parameters. Notably, this top-performing fabric met or exceeded the EN 149:2001+A1:2009 standard for breathing resistance and filtration efficiency and, in combination with additional filter layers, met the requirements or exceeded class FFP2 (filtering face piece). This study underscores the importance of meticulous material selection and quality control in optimizing PPE (personal protective equipment) performance and user safety, providing valuable insights for mask manufacturers and healthcare professionals. [ABSTRACT FROM AUTHOR]

This study investigates the degradation of six different types of absorbable surgical threads commonly used in clinical practice, focusing on their response to exposure to physiological fluids. The threads were subjected to hydrolytic and enzymatic degradation in physiological saline, bile, and pancreatic juice. Our findings demonstrate that bile and pancreatic juice, particularly when contaminated with bacterial strains such as Escherichia coli, Klebsiella spp., and Enterococcus faecalis, significantly accelerate the degradation process. Using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and tensile strength testing, we observed distinct differences in the chemical structure and mechanical integrity of the sutures. Principal component analysis (PCA) of the FTIR spectra revealed that PDS threads exhibited the highest resistance to degradation, maintaining their mechanical properties for a longer duration compared with Monocryl and Vicryl. These results highlight the critical role of thread selection in gastrointestinal surgeries, where prolonged exposure to bile and pancreatic juice can compromise the suture integrity and lead to postoperative complications. The insights gained from this study will contribute to improving the selection and application of absorbable threads in clinical settings. [ABSTRACT FROM AUTHOR]

This article contains an advanced analysis of the properties of solid wire electrical contacts produced by ultrasonic welding, both with and without varnish. The main disadvantage of ultrasonic welding of thin wires is the inability to achieve acceptable peel force and tensile strength, which is mainly due to the deformation and thinning of the wires. This study deals with ultrasonic welding using a ring of thin solid copper wires that minimises the deformation and thinning of the wires. The influence of welding parameters such as energy, pressure and amplitude were systematically analysed. Based on these parameters, the optimum welding programme and control method was determined to weld unvarnished and varnished wires. The investigations included electrical resistance tests, optical microscopy, micro-hardness measurements, peel tests and tensile tests, and the measurement of energy consumption. The results showed no significant differences in microstructure and hardness between varnished and unvarnished joints. Ultrasonic joints of varnished wires achieved lower electrical conductivity (by 38%), lower tensile strength (by 3%) and higher peel strength (by 7%), while the welding process was more sustainable in terms of energy (by 6.6%) and time consumption (without preprocessing). [ABSTRACT FROM AUTHOR]

Bonding is the key step in the fabrication of microfluidic devices. In the conventional approaches for the fabrication of polymer-based microfluidics, the substrate and cover plate were fabricated and then bonded to enclose the micro channels. Various methods have been invented for bonding polymer-based microfluidics, e.g. adhesive bonding, solvent bonding, thermal fusion, etc., materials with the same or different materials were bonded. The bonding quality of the polymer-based microfluidics is critical during use, leakage or even detachment is not allowed. The bonding quality of polymer-based microfluidic devices has been evaluated in different ways, some of the typical methods include the tensile test, shear test, and burst opening test, and each method has its own strengths and weaknesses. The standard procedure for bonding strength test hasn't been established yet. In this study, different evaluation methods for bonding quality were discussed and compared in detail, the application scenarios for each method are also discussed. An outlook for the future standardization trend of bonding test methods for microfluidic device is also provided in this study. [ABSTRACT FROM AUTHOR]

The current study investigates the tensile behavior of SiC/SiC minicomposites, focusing on the efficacy of epoxy encapsulation in extracting the intrinsic fiber bundle response. Three minicomposite types were examined: two with Hi‐Nicalon Type‐S fibers and one with Tyranno ZMI fibers. Tensile tests were performed on minicomposites and fiber tows, both bare and epoxy‐encapsulated, whereas interface properties were measured via fiber push‐in tests. The results demonstrate that epoxy encapsulation partially mitigates non‐uniform loading in minicomposites with discontinuous matrices. Theoretical limits on fiber bundle strength, estimated using micromechanical models based on weakest‐link statistics and shear lag theory, are similar to measured encapsulated tow strengths when failure occurs within the elastic regime of the epoxy. In some cases, microstructural defects such as fiber–fiber contacts and debonded coatings play important roles in limiting composite strengths relative to theoretical values. Although encapsulation does not always directly improve properties, it provides useful context for evaluating composite performance and exposing microstructural limitations unaccounted for in idealized models. [ABSTRACT FROM AUTHOR]

Highlights Present study comprehensively explores the phenomenon of in‐plane fiber waviness in glass/epoxy fiber reinforced polymer (GFRP) composites. Utilizing a pioneering technique that employs a semi‐circular bar to induce controlled fiber waviness, coupled with image processing using OpenCV library in Python coding for precise measurement and analysis of in‐plane fiber waviness. This defect is commonly found in components fabricated with fiber‐reinforced composites. During the process of manufacturing fibers may deviate from their intended orientation due to process variables or resin flow dynamics. Understanding in‐plane fiber waviness is crucial due to its impact on mechanical properties of composites. It is essential for optimizing manufacturing processes and ensuring enhanced structural performance in diverse engineering applications through analysis of strength and failure mechanism. A novel study was conducted by introducing a circular cutout within the fiber waviness region to investigate the combined effect of multiple defects. The experimental tensile test reveals that as waviness ratio (WR) increases a significant decrease in its tensile strength and vice versa. The study incorporates scanning electron microscopy (SEM) image analysis to examine composite failure. By advancing the understanding of in‐plane fiber waviness and its implications, this research significantly contributes to ongoing efforts in composite design and optimization. Adopting a cutting‐edge method to create controlled fiber waviness that makes use of a semi‐circular bar. Image processing with Python code that makes use of the OpenCV package to precisely measure and analyze in‐plane fiber waviness. A new investigation was carried out to examine the combined effect of multiple flaws by creating a circular cutout within the fiber waviness zone. [ABSTRACT FROM AUTHOR]

The presence of α casing in beta titanium can be detrimental to various forming applications and can be eliminated through chemical milling. The effect of the chemical milling process on the removal of alpha casing from the surface of beta titanium has been investigated extensively. Chemical milling is performed at different solution concentration ratios, and the specimens are characterized using Vickers hardness and surface roughness. The optimum results for chemical milling with a high material removal rate of 3.85 mm3/min are obtained with HF (10%) and HNO3 (10%). The effect of chemical milling on the mechanical strength of beta titanium is studied through tensile tests at room temperature and at increased temperature (200 °C). The maximum percentage of elongation obtained after chemical milling is around 24.4%, compared to 1.7% observed with the as-received specimen. Comprehensive analysis through optical microscopy, XRD, and EBSD confirmed the successful removal of the α casing from the β-Ti alloy at both 0.7- and 0.5-mm chemical milling depths. The effectiveness of the chemical milling process is further investigated through fractography analysis of the tensile-tested specimens. Chemical milling with the specified solution proves to be an effective method for enhancing α casing removal and mechanical performance of β-Ti alloys, making it a promising technique for various industrial applications. [ABSTRACT FROM AUTHOR]

The 3D printing technique has recently become more prevalent among researchers for the fabrication of nanocomposites. The low crystallinity of polylactic acid (PLA) leads to the poor mechanical and thermal properties of its 3D-printed products, which restrict their applications in many fields. To overcome the limitations of PLA, the present work aims to develop PLA-based bionanocomposite filaments with varying percentages (1, 3, and 5 wt%) of crystalline nanocellulose (CNC) through a single screw extruder. The filaments will be further utilized for the development of bionanocomposite samples to evaluate their properties. The effect of CNC reinforcement on the chemical structure of the filaments was analyzed by FTIR analysis. XRD analysis revealed that the crystallinity of the filaments was significantly improved due to the nucleating effect of CNC. The maximum crystallinity was observed in the filament containing 1 wt% CNC, which was 26% higher than the pure PLA filament. The thermal and mechanical performance of the filaments was also considerably improved after CNC reinforcement, which was confirmed by DSC-TGA and tensile test analysis. The maximum tensile strength and tensile modulus were observed to be 48.9 MPa and 1700 MPa, respectively, in the filament reinforced with 1 wt% CNC, which was 35.5% and 21.89%, respectively, higher than those of the pure PLA filament. Rheological analysis showed that the complex viscosity, storage modulus, and loss modulus of the filaments were significantly affected by the reinforcement of CNC. [ABSTRACT FROM AUTHOR]

Cribellate silks, produced by ancient spiders, are fascinating because they feature a highly sophisticated, 3D hierarchical structure consisting of filaments with different diameters and shapes. Here, the smallest and thinnest constituents of the cribellate silk are investigated: nanofibrils that form a dense mesh that is supported by larger fibers. Analysis of their structure via atomic force and transmission electron microscopies shows that they are flattened fibrils, only ≈5 nm thick — thinner than any other natural spider silk fibrils previously reported. In this work, the first mechanical tensile testing experiments on these fibrils are carried out, which reveals that the fibrils show an outstanding extensibility of at least 1100%, almost twice as much as the most stretchable spider silk previously reported. Based on these extraordinary findings, this work significantly expands the parameter space of materials properties attainable by spider silks and provides further insights into their nanomechanics. [ABSTRACT FROM AUTHOR]

AbstractInsufficient adhesion between ultrathin wearing courses (UTWCs) and substrate layers can result in pavement distress. Epoxy asphalt exhibits potential as a tack coat due to its high bonding strength and thermal stability. However, its rapid curing may pose challenges to construction schedules. This study aimed to optimize the formulations of epoxy asphalt tack coats (EATCs) to enhance the interfacial adhesion and working performance of UTWCs. The adhesion of EATCs was evaluated through rotational viscosity and tensile tests. Design parameters were optimized using analysis of variance and microscopic tests. Road performance was assessed via interlayer shear and tensile testing on three pavement structures. The results indicated that the curing agent strongly influenced the properties and curing kinetics of EATCs. Formulations containing complex polysebacic polyanhydride (CPSPA-EA) exhibited superior bonding while meeting construction schedules. Microscopic analysis of CPSPA-EA revealed a stable crosslinked network formed at 30% binder dosage. The amount of spraying significantly impacted the adhesion in UTWC structures. The optimal spraying amounts were 0.60 kg/m2 for asphalt concrete (AC-13), 0.55 kg/m2 for stone matrix asphalt (SMA-13), and 0.40 kg/m2 for cement concrete substrate layers. These findings presented an optimization framework for designing EATCs to enhance UTWCs working and long-term performance through balanced tack formulations and application parameters. [ABSTRACT FROM AUTHOR]

Reliable long‐term function is crucial for flexible and soft bioelectronics. Mechanical defects and permeation of water molecules across the various device layers are the prime drivers of failure, and particularly in applications requiring continuous contact with biofluids (i.e. for implantable applications). To address demanding needs of miniaturization, mechanical compliance and water impermeability, ultra‐thin high‐barrier encapsulations are a promising way to improve device reliability. In this work, the encapsulation properties of vapour phase infiltration (VPI) of inorganic Al2O3 layers deposited by atomic layer deposition (ALD), as bilayers with TiO2, onto polyimide and parylene C organic substrates are investigated. The layers are grown in a single reactor and the infiltration is performed in a single process, with a resulting nanometric infiltration depth. Mechanical integrity and hermeticity are characterized through tensile fragmentation tests and accelerated aging tests. Flexible Magnesium sensors monitor water vapor permeability in situ. A remarkable improvement in the crack onset strain (∽2.56 times), interfacial shear strength (∽2.1 times), water vapour transmission rate (∽5.2 times) and lifetime performance (∽7.1 times) is achieved, compared to the non‐infiltrated ALD coatings. Pluri‐infiltrated multilayers are proposed as alternatives to conventional coatings. This work is envisioned to accelerate research progress on hermetic packaging of flexible bioelectronics. [ABSTRACT FROM AUTHOR]

Highlights An image‐based fiber orientation analysis technique has been employed to study the effect of initial charge coverage and preferential fiber alignment on the flow‐induced fiber orientations in carbon fiber sheet molding compounds (SMCs). The initial charge coverage area exhibited minimal fiber reorientation while significant fiber alignment in the flow direction was observed in the regions of greatest flow. Novel subsurface analysis using the same full‐field orientation analysis technique also showed the presence of a skin‐core structure with greater flow‐induced fiber alignment at the mold surfaces, while the core retained more of the initial fiber orientation distribution. Edge effects were also revealed by this analysis at the mold walls. Tensile testing from two orthogonal directions showed that panels molded from lower charge coverage resulted in better mechanical performance and lower anisotropy. Moreover, by encouraging charge flow in the preform's preferential alignment direction, high tensile stiffness and strength in the preferred direction were achieved (56.7 GPa and 238.9 MPa, respectively) at 30% fiber volume fraction. This provides a practical demonstration of the value in controlling fiber orientation, with respect to charge positioning and mold flow, to maximize and tailor the composite performance of SMCs typically used for automotive applications. Low‐cost scanning technique is extended to assess internal fiber orientations Full‐field orientations are measured before and after molding Investigation of how charge size and shape can affect orientations Combining effects of flow and initial orientation to tailor SMC performance Circular statistics provides a thorough analysis of orientation distributions [ABSTRACT FROM AUTHOR]

AbstractIn the present investigation, the selective laser melting (SLM) technique has been utilized for the 3-dimensional printing (tensile test specimens) of SS316L steel powder at 00 (horizontal) and 900 (vertical) angles. Further, an experimental and finite element analysis approach has been made to analyse the effect of printed orientation or direction on the Hollomon power law parameters (strain hardening exponent (n) and strength coefficient (K)) and ductile damage parameters (fracture strain (εf), stress triaxiality (η) and strain rate (ε̇)). The influence of printing orientation on plastic deformation behavior has also been analysed. The results revealed that 00 angle 3D-printed specimens exhibited 11.05%, 21.97% and 9.50% more yield strength, tensile strength and elongation than 900 angle 3D-printed tensile test specimens. Further, the strain hardening exponent (n) and strength coefficient (K) (Hollomon power law hardening model parameters) for 00 angle 3D-printed specimens are 35.80% and 32.47% more than the 900 angle 3D-printed tensile test specimens respectively. The fracture strain for 00 angle 3D-printed specimens is 37.82% less than the 900 angle 3D-printed tensile test specimens. The percentage difference between FEA and experimental results is less than 5% which shows the good prediction capability of estimated Hollomon power law parameters and ductile damage model parameters with developed FEA model for 00 and 900 3D printed specimens. [ABSTRACT FROM AUTHOR]

Mg-9 Al-1 Si alloy was prepared by gravity casting of copper metal mo Id, and the microstructure of the alloy was controlled by ultrasonic treatment at different time before solidification. The evolution of microstructure and morphology and its effect on mechanical properties of Mg-9Al-1Si alloy under ditferent ultrasonic treatment time were characterized by means of OM, XRD, SEM and tensile test. The results show that without ultras-onic treatment, crMg matrix is coarse dendrite, coarse Chinese character-like Mg2Si phase has obvious agglomeration, β-Mg17Al12 phase is intermittently reticulated along the dendrite boundary, ultrasonic treatment can significantly refine the micro structure of the aloy, the grain size of c-Mg matrix changes from coarse dendritic to flocculent andthe Chinese character Mg2Si phase is refined into strip or thin line, and the distribution becomes uniform. The reticular trend of &#946-Mg17Al12 phase weakens, and a large number of lamellar &#946-Mg17Al2 phases appear at the boundary. With the increase of ultrasonic time, the effect of ultrasonic cavitation and sound flow can obviously improve the microstructure of the alloy, but the effect of ultrasonic cavitation and acoustic flow on microstructure refinement is weakened for too long. Therefore, the mechanical properties of Mg-9Al-1Si alloy were significantly improved after ultrasonic treatment, and increased at first and then decreased with ultrasonic treatment time, in which the improvement of ultrasonic treatment of 20 min was the highest, which was 72,74 MPa and 2. 31% higher than that of untreted aloy respecively. [ABSTRACT FROM AUTHOR]

Purpose: Additive lamination manufacturing (ALM), as a novel additive manufacturing technology, builds up the geometry via the lamination of fiber-reinforced polymer (FRP) fabric laterally, rendering it suitable for fabricating large-scale Stay-in-Place concrete formwork. This paper aims to investigate the control parameters and structure performance of ALM and assess its application for the fabrication of large-scale concrete formwork. Design/methodology/approach: Based on previous feasibility studies, this research systematically investigates the control and material parameters that influence horizontal and vertical extrusion speeds, as well as the overall quality of ALM. Once the system parameters are established, a series of prototypes are fabricated and tested to validate the tensile strength of the formwork and its reinforcement capabilities. In addition, this study assesses the potential geometric freedom and implementation constraints of ALM. Findings: This research identifies the essential control parameters for path planning in ALM and examines their impact on fabrication. In addition, this paper evaluates ALM's strengths and limitations in producing concrete formwork for large-scale concrete structures, comparing these to industry benchmarks. Originality/value: A critical challenge in additive manufacturing lies in its scalability and compatibility with existing construction processes. In comparison to concrete, FRP offers advantages such as being lighter, easier to handle and providing surface protection and reinforcement. These qualities make FRP superior for formwork and compatible with existing building standards. Despite its advantages and potential, the current path planning and control model in 3D printing do not apply to ALM due to its novel build-up process. Also, the performance of fabricated parts as part of integrated large-scale structures is yet to be studied. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to examine the impact of specific printing factors, such as layer height, line width and build orientation, on the overall quality of fused filament fabrication (FFF) 3D printed structures. The project also intends to use response surface methodology (RSM) to maximize ultimate tensile strength (UTS) while lowering surface roughness and printing time. Design/methodology/approach: This study used an FFF printer to fabricate samples of polylactic acid (PLA), which were then subjected to assessments of tensile strength and surface roughness. A tensile test was conducted under standardized conditions according to the ASTM D638 standard test method using the AG-50 kN Shimadzu Autograph. The Mitutoyo Surftest SJ-210, which utilizes a needle-tipped inductive method, was used to determine surface roughness. RSM was used for optimization. Findings: This work provides useful insights into how the printing parameters affect FFF 3D printed structures, which may be used to optimize the printing process and improve PLA-based 3D printed products' qualities. The determined optimal values for building orientation, layer height and line width were 0°, 0.1 mm and 0.6 mm, respectively. The total desirability value of 0.80 implies desirable outcomes, and good agreement between experimental and projected response values supports the suggested models. Originality/value: Previous RSM studies for 3D printing parameter optimization focused on mechanical properties or surface aspects, however, few examined multiple responses and their interactions. This study emphasizes the relevance of FFF parameters like line width, which are often overlooked but can dramatically impact printing quality. Mechanical properties, surface quality and printing time are integrated to comprehend optimization holistically. [ABSTRACT FROM AUTHOR]

This work uses finite elements to build and examine composite laminates constructed of carbon fiber reinforced polymer (CFRP). The great strength compared to weight of composite materials is an important characteristic. Using the finite element method and the ANSYS program, the optimal resistance model for tensile testing and compressive testing was chosen. This article will present hybrid 3D simulation models of woven materials reinforced with fibers, with the goal of optimizing the model by adjustment of the reinforcement angle. The Math-Cad and ANSYS software will be used to compare these reinforced models from different angles in addition to testing them under compressive and tensile loads. The results of the tensile testing of the models were illustrated using von Mises stress theory of failure. Of all the models, the tenth is the one that is least susceptible to failure. The resistance to breakdown is weaker (51.5%) when compared to the resistance to the fifth model's breakdown. The von Mises stress theory of failure was used to illustrate the findings of the compressive testing of the models. The third model is the one that has the lowest failure probability. The resistance to collapse is significantly lower (48%) than the resistance to the fifth model's disintegration. Additionally, the results show that the sixth model had the lowest shear stress (1.5686 MPa), whereas the tenth model had the highest shear stress (22.734 MPa). For resistance to stresses, strains, and deformations caused by the tensile test and compression test, the third model is the best selection. [ABSTRACT FROM AUTHOR]

This study explores the potential of Micronized Biomass Silica (MBS), a high-silica agricultural byproduct, as a partial substitute for cement in concrete mixtures. MBS can lead to a reduction in CO2 emissions associated with cement production, contributing to more sustainable concrete practices. The study explores the effects of replacing cement with MBS in varying percentages, ranging from 3% to 12% at intervals of 3%, to identify the optimal mix combination. Concrete samples, both with and without the addition of Micronized Biomass Silica (MBS), were subjected to compressive strength and split tensile strength tests. The results indicate that incorporating up to 6% MBS enhances the strength of concrete, while higher percentages lead to a decrease in strength. Additionally, a detailed microstructural analysis of the concrete with MBS was performed using Scanning Electron Microscopy (SEM), which provided insights into the mechanisms underlying the observed strength development. The optimal percentage of MBS for enhanced strength development is 6%, as it improves compressive and split tensile strength while enhancing the interfacial transition zone. The findings suggest that MBS can be effectively utilized to improve concrete performance at optimal replacement levels. [ABSTRACT FROM AUTHOR]

Mechanical properties and behaviors of bamboo joined by different connections were considered in this work. Makino bamboo (Phyllostachys makinoi) culms from Taiwan were used as the connection material to explore the form of cross-lap joints. Since the cross-lap joint is a common joint in bamboo structures, the mechanical properties of tension, slip, and rotation were evaluated for three types of joints: lashing joint, iron wire joint, and steel bracket joint, under different load conditions. The results showed that the ultimate load of bamboo culms under lateral partial compression has a positive correlation with the number of bamboo nodes and the relative distance to the base-section of the bamboo culms. The mid-sections and end-sections have similar uniaxial compressions in the transverse orientation. According to results of tensile testing, the tensile stiffness of the three joint types is as follows in descending order: iron wire joint, lashing joint, and steel bracket joint, with the reverse order for ultimate load testing. In terms of slip testing, the withstanding of ultimate loads and increases in slip stiffness can be attributed to bamboo nodes that assist in creating slip stiffness in lashing joint. However, ultimately, steel bracket joints hold the highest slip stiffness. Our findings for rotation stiffness value show the following tendency: steel bracket joint > lashing joint > iron wire joint. [ABSTRACT FROM AUTHOR]

For a hygiene paper such as tissue and towel, strength, softness, and absorbency are known as attributes that a user is looking for. It is proposed here that purchasing decisions are likely to be influenced by in-use experiences, which may be quite different from the physical properties measured with current standardized tests. There have been continuous efforts on developing physical test methods to replace subjective in-use tests because the benefits of the former are too significant to be overlooked. This paper considered some in-use test methods for paper towel products that can be carried out by panel members quickly in the course of sensory panel testing. In addition, laboratory tests were developed in an attempt to quantify such input. The sensory panel testing showed that (wet) strength and absorbency were the key contributions to the performance of paper towels. Softness did not show any significant contribution to it. Wet strength showed a high correlation with absorbency. The (wet) ball burst strength had the highest correlation with the in-use strength. Although both the tensile strength and the ball burst strength had a high correlation with preference, the ball burst tester is preferred because more reproducible and simpler to operate. [ABSTRACT FROM AUTHOR]

This research focuses on enhancing the machinability and formability of tool steels by applying different heat treatment scenarios. Machinability is the process of cutting metals with the least energy effort, while formability is the ability of a metal to be shaped into different forms without severe damage. Enhancing machinability and formability improves dimensional tolerance and surface finish and increases the lifetime and reliability of tool steels. This research will use two tool steel materials, "D2" and "O1," which are widely used in industry. They contain high percentages of carbon by weight (1.55% and 0.95%, respectively). The "O1" tool steel is used in blanking dies and room-temperature cutting tools, whereas the "D2" tool steel is used for carpentry cutting tools and gauges. The different heat treatment scenarios are based on the latest literature, which shows excellent results with other materials. The heat treatment plan is set to cover various scenarios to determine the most effective treatment for machinability and formability. The experimental work will include several mechanical tests: tensile tests, compression tests, hardness tests, and toughness tests. The conclusions regarding the different heat treatments will be based on the test results. [ABSTRACT FROM AUTHOR]

The mechanical properties of sclera play an important role in ocular functions, protection, and disease. Modulating the sclera's properties by exogenous crosslinking offers a way to expand the tissue's range of properties for study of the possible influences on the eye's behavior and diseases such as glaucoma and myopia. The focus of this work was to evaluate the effects of genipin crosslinking targeting the porcine perilimbal sclera (PLS) since the stiffness of this tissue was previously found in a number of studies to influence the eye's intraocular pressure (IOP). The work includes experiments on tensile test specimens and whole globes. The specimen tests showed decreased strain-rate dependence and increased relaxation stress due to the cross-linker. Whole globe perfusion experiments demonstrated that eyes treated with genipin in the perilimbal region had increased IOPs compared to the control globes. Migration of the cross-linker from the target tissue to other tissues is a confounding factor in whole globe, biomechanical measurements, with crosslinking. A novel quantitative genipin assay of the trabecular meshwork (TM) was developed to exclude globes where the TM was inadvertently crosslinked. The perfusion study, therefore, suggests that elevated stiffness of the PLS can significantly increase IOP apart from effects of the TM in the porcine eye. These results demonstrate the importance of PLS biomechanics in aqueous outflow regulation and support additional investigations into the distal outflow pathways as a key source of outflow resistance. [ABSTRACT FROM AUTHOR]

To solve the problem of the lack of physical properties of pedicels and the changing pattern for designing the end-effector of tomato harvesting robot and different harvesting modes, research was conducted on the physical properties of tomato pedicels and their change patterns. Using a Universal TA texture analyzer, tensile, three-point bending, and shearing tests were performed on tomato pedicels in the early firm-ripening stage. The tomato variety used was Syngenta Spectrum, cultivated seasonally with two crops per year. Spring crop tomatoes were used in this study. The experimental results provide a theoretical basis for designing tomato harvesting robots across three harvesting modes. Tensile tests measured the pull-off force and tensile strength of the abscission zone with varying diameters. These results are crucial for designing robots using a tensile harvesting mode. The location of the tomato pedicel significantly affects the shearing force. A one-way test was conducted on the shearing part. The results showed that the shearing force and energy required for the proximal pedicel are significantly greater than for the distal pedicel. To reduce the shearing force and energy needed by the end-effector's shearing mechanism on distal pedicels, a response surface test was conducted. Three factors were examined: shearing speed, angle, and distal pedicel diameter. Design–Expert software optimized these factors to minimize shearing energy and force, leading to the best shearing parameters for different distal pedicel diameters. From the three-point bending tests, the average maximum bending breaking force, bending modulus, and bending strength of the tomato abscission zone were determined. These findings offer a theoretical basis for designing tomato harvesting robots with a bending-type harvesting mode. [ABSTRACT FROM AUTHOR]

Most of the therapeutic systems developed for managing chronic skin wounds lack adequate mechanical and hydration properties, primarily because they rely on a single component. This study addresses this issue by combining organic and inorganic materials to obtain hybrid films with enhanced mechanical behavior, adhesion, and fluid absorption properties. To that aim, chitosan/hydrolyzed collagen blends were mixed with halloysite/antimicrobial nanohybrids at 10% and 20% (w/w) using glycerin or glycerin/polyethylene glycol-1500 as plasticizers. The films were characterized through the use of Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and electron microscopy. The mechanical properties were evaluated macroscopically using tensile tests, and at a nanoscale through atomic force microscopy (AFM) and nanoindentation. Thermodynamic studies were conducted to assess their hydrophilic or hydrophobic character. Additionally, in vitro cytocompatibility tests were performed on human keratinocytes. Results from FTIR, TGA, AFM and electron microscopy confirmed the hybrid nature of the films. Both tensile tests and nanomechanical measurements postulated that the nanohybrids improved the films' toughness and adhesion and optimized the nanoindentation properties. All nanohybrid-loaded films were hydrophilic and non-cytotoxic, showcasing their potential for skin wound applications given their enhanced performance at the macro- and nanoscale. [ABSTRACT FROM AUTHOR]

The aim of this study is to determine experimentally the higher material parameter g$g$ of a metamaterial with a triangular substructure and to verify a higher‐gradient elasticity model for beams with internal substructures or microstructures. The investigations of the higher‐gradient elasticity models of Bernoulli‐Euler and Timoshenko beams with a periodic triangular substructure in Khakalo et al. show that the bending stiffness strongly depends on the geometrical parameters of the lattice structure. To achieve this goal, beams with triangular substructures were additively manufactured using fused deposition modeling and stereolithography. They were experimentally investigated in tensile and bending tests. Three different types of beams with triangular substructures were produced, consisting of one, two and four layers of triangular beams, using two different materials: Polylactide and epoxy resin. The higher material parameter g was quantitatively determined based on the experimental results using inverse analysis. The results are valid for these specific variations of the substructure and can adequately represent the elastic size effects. In addition, this study investigates the relationship between the bending stiffness and the geometric parameters of the lattice structure as well as the influence of the curing time on the elastic properties of epoxy resin. The experiments involved testing the triangular beams under tensile and bending loads. The numerical and experimental results were compared using digital image correlation. Based on the experimental data, a higher gradient material parameter representing the geometric structure of the lattice was determined. [ABSTRACT FROM AUTHOR]

In this work, a micro-solid-phase extraction technique employing polylactic acid (PLA)/ZnO-chitosan bio-nanocomposites was developed to isolate selected triazines from aqueous environments. Subsequently, the isolated analytes were injected into gas chromatography–mass spectrometry instrument following solvent desorption. The PLA bio-nanocomposites, incorporating varying concentrations of synthesized ZnO-chitosan, were fabricated utilizing the solvent casting method. The PLA/ZnO-chitosan bio-nanocomposites and ZnO-chitosan hybrid nanoparticles were analytically characterized by the use of field emission scanning electron microscopy, Fourier-transform infrared spectroscopy, tensile testing, and X-ray diffraction. Tensile tests showed that adding ZnO-chitosan hybrid nanoparticles to PLA increased both its tensile strength and elongation at break. Key parameters of the extraction process involving PLA/ZnO-chitosan bio-nanocomposites such as nanoparticle concentration, ionic strength, sample pH, extraction duration, and solvent choice were meticulously examined and optimized. The refined extraction device exhibited high sensitivity and rapidity, achieving analytical parameters with a detection limit ranging from 0.85 to 2.5 ng L−1 and a quantification limit between 5 and 10 ng L−1. Equilibrium was attained within 20 min. Over a concentration range of 10–1000 ng L–1, the method showed linearity, with a correlation value higher than 0.9997. Having a relative standard deviation between 4 and 8%, repeatability was confirmed at 100 ng L−1. Ultimately, the proposed extraction device's effectiveness was confirmed by successfully recovering specific analytes from natural water samples, with relative recovery percentages ranging from 98 to 102%, indicative of negligible matrix interference. [ABSTRACT FROM AUTHOR]

This study investigates the comparative performance of Copper-Iron (CuFe) and Copper-Tin (CuSn) alloys in crimping processes, with a focus on their mechanical, electrical, and corrosion-resistance properties. Crimping is a critical method for creating reliable electrical and mechanical connections, particularly in environments subjected to significant mechanical stress and varying temperatures [1]. CuFe alloys, known for their superior mechanical strength and hardness, present challenges in crimping due to their increased resistivity and reduced ductility. Conversely, CuSn alloys offer a balance between electrical conductivity, ease of crimping, and corrosion resistance, making them a preferred choice in many industrial applications. This research aims to provide a comprehensive analysis of how the distinct properties of CuFe and CuSn alloys influence the crimping process, ultimately guiding material selection for optimized performance in various applications [2]. Experimental data will be drawn from tensile strength tests, electrical resistance measurements, and corrosion tests, providing a holistic understanding of the advantages and limitations of each alloy. [ABSTRACT FROM AUTHOR]

With the increasing focus on reducing carbon emissions, hydrogen has emerged as a promising alternative energy source. However, the safe transportation of hydrogen poses challenges due to its potential impact on the integrity of pipeline materials. This study aims to investigate the effect of hydrogen charging time on the plastic behavior and ductile fracture characteristics of API 5L X42 pipelines, which are commonly used for transporting hydrocarbons. Tensile tests were conducted on various types of hydrogen-charged specimens at room temperature to assess different fracture modes. Hydrogen was introduced into the specimens using a cathodic electrolytic method, and 24-h charging time durations were considered. Finite element analyses were performed on standard dog-bone and notched tension specimens to evaluate the plastic behavior, employing the Swift hardening law to model the flow stress. Numerical analyses were conducted to determine the loading path leading to fracture initiation. A damage framework based on the Hosford–Coulomb model was utilized to predict ductile fracture under non-proportional loading conditions. The findings of this study provide insights into the fracture behavior of pipelines under hydrogen exposure, aiding in the design and assessment of safe and reliable hydrogen transport systems. [ABSTRACT FROM AUTHOR]

The utilization of biofiber in recent years has significantly increased due to its advantages like being environmentally friendly, availability, and low costs. This paper investigates the physicochemical, mechanical, and morphological properties of the yucca fiber extracted by three methods such as water‐retting, traditional, and chemical methods. These analyses are designed to evaluate the extraction methodology and the hypothesis of the influence of harvesting location and growth conditions of the fiber. Various technologies are used, such as SEM, FTIR, XRD, and tensile tests. The fiber extracted by water retting is the strongest in the mechanical analysis with a strength of 690.48 MPa, followed by fiber extracted with the traditional method with 685.48 MPa, also 673.06, 657.94, 373.68 MPa for the fiber extracted by the chemical method using 3%, 5%, 10%NaOH respectively. The fiber obtained by the water retting method also has a higher chemical composition with 80.25% cellulose, 10.45% lignin, and 13.75% hemicellulose. The morphological characteristics are examined using Scanning Electron Microscopy. The crystallinity index ranged from 61.75% to 70.77%, and crystallite size from 1.73 to 2.04 nm is calculated from the XRD analysis. All these results confirm that yucca fiber can be a good sustainable choice for composite reinforcement. [ABSTRACT FROM AUTHOR]

Isaac Newton once contemplated the fall of an apple, setting in motion a revolution in the understanding of gravity. In a similar spirit of curiosity and inquiry, here a journey is embarked upon to explore the intricate world of viscoelastic damping for polydimethylsiloxanes (PDMS). Inspired by the notion that even the simplest of phenomena can yield profound insights, a novel approach to study damping in silicone elastomers through a simple ball drop test is introduced. This novel solution allowes for precise measuring and analyzing the material's damping characteristics under various conditions. By carefully controlling the release and monitoring, the response of the falling ball by simple video tracking, valuable insights into the key viscoelastic properties of silicone blends are extracted, including rebound resilience, Young's modulus, and complex modulus. Through the analysis of trajectory data generated during the sphere's interaction with the silicone damper, dynamic and static material parameters are determined. Remarkably, these outcomes closely align with results obtained from cost‐intensive and high‐maintenance industrial measurement setups such as dynamic thermomechanical analysis (DTMA) or tensile testing. This approach not only simplifies the complexity of the system but also offers a cost‐effective and efficient means of gaining essential knowledge in material science. [ABSTRACT FROM AUTHOR]

Recently, plaster has gained increasing attention as a mechanical and environmentally friendly option and is an effective alternative to traditional cement products. Additionally, polyester has an effective impact on the mechanical properties of materials, in addition to being one of the most environmentally friendly materials. However, studies are still ongoing to reach the best ratios of polyester resin, polyester hardener, and gypsum plaster that can improve mechanical properties. This research aims to investigate the impact of these components at various ratios (30%, 45%, and 60%) of gypsum plaster weight on the mechanical properties of plaster material. This study is carried out by conducting compression and tensile tests for three ratios, which are considered among the most important mechanical tests according to their applications. In addition, the environmental emissions resulting from the three different ratios of plaster are evaluated to determine their environmental impact. This study found that the largest ratio (30%) was the most effective from an economic and mechanical point of view, while achieving lower carbon emissions compared to the other ratios, which enhances the trend towards achieving the environmental goals of the Kingdom of Saudi Arabia's Vision 2030 to reach zero emissions. This study is highly significant both in terms of scientific research and practical application across a range of industries, since it integrates the enhancement of material performance with the achievement of environmental sustainability requirements. [ABSTRACT FROM AUTHOR]

In this paper, the mechanical properties and internal stress condition of the reinforcing bar sleeve connectors with ferro-tailed mineral sand cementitious grout as filler material were analyzed as research objects. Firstly, an experimental study was carried out on the reinforcing bar sleeve connectors of iron tailing sand grout with a 40% substitution rate of mechanism sand to analyze the mechanical properties of different grout types, age, and reinforcement diameters under unidirectional tensile, high stress, and large deformation of repeated tensile and compressive stresses. Next, five groups of sleeve joints with different anchorage lengths were set up for unidirectional tensile tests. The results show that, with the decrease of the diameter of the reinforcement, the grip force and bond strength of the iron tailing sand grout on the internal reinforcement gradually increase. Under conditions of large deformation and high stress due to repeated tensile loading, the residual deformation and total elongation of iron tailing sand grout sleeve joints are satisfactory. Additionally, the restraining anchorage effect of iron tailing sand grout in the end section is small. The utilization rate and integrity of iron tailing sand grout in the initial anchorage section are better. [ABSTRACT FROM AUTHOR]

This study examines the mechanical properties, specifically strength and stiffness, of technical hemp and flax fibers grown in Romania. Tensile testing was employed to determine stress–strain curves and the Young's modulus and to assess the failure strength of both fiber types. Although samples of various lengths were tested, no significant length-dependent variations were observed. However, a strong dependence on fiber diameter was noted, with the smallest diameters approaching the documented strength of elementary fibers. Due to the considerable variability in the experimental results pertaining to the characteristics of the reinforced fibers, a statistical analysis using a two-parameter Weibull distribution was employed. The analysis revealed three distinct stress–strain curve profiles, i.e., linear, bi-linear, and tri-linear patterns, with the average ultimate stress ranging from 412 to 566 MPa for hemp and 502 to 598 MPa for flax. [ABSTRACT FROM AUTHOR]

This research investigates the tensile strength and microstructural properties of stainless steel 316L, comparing samples fabricated using additive manufacturing (AM) to those produced via conventional manufacturing techniques such as forging and casting using stainless steel 316L for its mechanical performance and corrosion resistance. Tensile tests revealed that AM samples had an ultimate tensile strength (UTS) of 650 MPa, a yield strength of 550 MPa and an elongation at break of 20%, and conventionally manufactured samples achieved a UTS of 580 MPa, a yield strength of 450 MPa and a higher elongation at break of 35%. The reduced ductility of AM samples is offset by their higher strength. Scanning electron microscopy (SEM) analysis showed that AM samples had a refined grain structure, with grain sizes ranging from 1 to 5 µm, whereas conventionally produced samples exhibited larger grain sizes of 10 to 20 µm, contributing to their increased ductility. This shows that while AM processes can give a rather high strength, the ductility property is simpler to attain with casting. Further work is needed to investigate post-processing techniques like hot isotropic pressing (HIP) and heat treatments for enhancing the ductility of AM parts as well as mechanical properties. [ABSTRACT FROM AUTHOR]

Laser-welding is a promising technique for welding NiTi shape memory alloys with acceptable tensile strength and comparable corrosion performance for biomedical applications. The microstructural characteristics and localized corrosion behavior of NiTi alloys in a simulated body fluid (SBF) environment are evaluated. A microstructural examination indicated the presence of fine and equiaxed grains with a B2 austenite phase in the base metal (BM), while the weld metal (WM) had a coarse dendritic microstructure with intermetallic precipitates including Ti2Ni and Ni4Ti3. The hardness decreased from the BM to the WM, and the average hardness for the BM was 352 ± 5 HV, while it ranged between 275 and 307 HV and 265 and 287 HV for the HAZ and WM, respectively. Uni-axial tensile tests revealed a substantial decrease in the tensile strength of NiTi WM (481 ± 19 MPa), with a reduced joint efficiency of 34%. The localized corrosion performance of NiTi BM was superior to the WM, with electrochemical test responses indicating a pitting potential and low corrosion rate in SBF environments. The corrosion rate of the NiTi BM and WM was 0.048 ± 0.0018 mils per year (mpy) and 0.41 ± 0.019 mpy, respectively. During welding, NiTi's strength and biocompatibility properties changed due to the alteration in microstructure and formation of intermetallic phases as a result of Ti enrichment. The performance and safety of welded medical devices may be impacted during welding, and it is essential to preserve the biocompatibility of NiTi components for biomedical applications. [ABSTRACT FROM AUTHOR]

In this study, bentonite clay was modified through silane treatment and calcination to enhance its compatibility with basalt fiber (BF) and epoxy in multiscale composites. The as-received bentonite (ARB) was subjected to silane treatment using APTES, producing silane-modified bentonite (STB), while calcination yielded calcined bentonite (CB). The modified clays were incorporated into basalt fiber-reinforced epoxy (BFRP) composites, which were fabricated using the vacuum-assisted resin transfer method (VARTM). Analytical techniques, including X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) spectroscopy, confirmed the structural changes in the clays. BET surface area analysis revealed a 314% increase in the surface area of STB and a 176% increase for CB. The modified clays also demonstrated reduced hydrophilicity and swelling behavior. Thermogravimetric analysis (TGA) indicated a minimal improvement in thermal stability, with the degradation onset temperatures increasing by less than 3 °C. However, tensile tests showed significant gains, with CB- and STB-reinforced composites achieving 48% and 21% higher tensile strength than ARB-reinforced composites. Tribological tests revealed substantial reductions in wear, with CB- and STB-reinforced composites showing 90% and 84% decreases in the wear volume, respectively. These findings highlight the potential of modified bentonite clays to improve the mechanical and wear properties of basalt fiber–epoxy composites. [ABSTRACT FROM AUTHOR]

Lime stabilization is a sustainable technique due to its use of local materials, increased durability, reduced maintenance, and improved resistance to water action. This paper examines the impact of lime stabilization on the mechanical, microscopic, and mineralogical properties of a tropical soil. Two types of lime, calcitic and dolomitic, were tested at 3% and 5% by weight. Compressive, indirect tensile and flexural test results and statistical analysis revealed that calcitic lime mixtures had higher strength and stiffness, whereas dolomitic lime mixtures exhibited greater deformability with higher tensile strain at break. Scanning electron microscopy indicated that the soil's porous matrix closed within 7 days for both lime types due to flocculation, with increased matrix interlocking over time. The calcitic lime mixture developed a more closed matrix compared to the dolomitic lime, which showed weaker cementing. X-ray diffraction analysis indicated higher consumption of clay minerals and a notable reduction in calcium hydroxide peaks in the lime-treated soils. The study concludes that calcitic lime provides better pavement performance for stabilizing the soil, enhancing its engineering properties while also being sustainable by reducing the need for raw material extraction and improving resilience to climate-related issues such as floods. [ABSTRACT FROM AUTHOR]

Re‐anchoring during severing of historical tendons Prestressed concrete bridges are increasingly being dismantled in Germany. The problem here is usually the insufficient knowledge of the properties of the materials used. In particular, it is difficult to determine the condition of the tendons and the grouting. In the course of dismantling, the cutting through of tendons away from the coupling joints can be advantageous for construction‐related reasons. A prerequisite for ensuring the structural safety of the dismantling section is successful bond anchoring of the tendons with the surrounding grout, the duct, and the concrete. In addition to a good condition of the tendons and the grouting, sufficient knowledge of this bond behavior is therefore essential. However, information on the bond properties of the prestressing steel used in the Unterrieden viaduct could hardly be found in the literature. For this reason, investigations were carried out during the dismantling of the Unterrieden viaduct to determine the condition of the tendons. This included strain recovery measurements to determine the existing prestressing and tensile tests on prestressing bars, which were removed from the structure subsequent to the strain recovery measurements. Furthermore, bond specimens were taken from the bridge and tested in the laboratory in order to draw conclusions about the anchorage behavior of the tendons. These investigations are intended to verify the assumptions made in the dismantling planning. [ABSTRACT FROM AUTHOR]