Composite Strips Research Articles

Microstructure of interfacial diffusion layer of cross-layered silver–copper composite strip and its effect on resistivity

Microstructure of interfacial diffusion layer of cross-layered silver–copper composite strip and its effect on resistivity

Lateral performance of circular wooden columns reinforced with high-performance bamboo-based composite

This study researches the lateral performance of wooden columns strengthened with the non-damage reinforcement method, which used high-performance bamboo-based composite (HPBBC) materials and steel strips to form a hollow reinforcement system and then jacketed and reinforced the wooden columns. Six wooden columns strengthened by non-damage reinforcing methods were subjected to low cyclic loading tests under horizontal loads with a constant axial pressure ratio. The horizontal loads, displacements, and strain distributions of different locations at the column root were measured. The experimental results showed that the reinforcement method improved the lateral performance of wooden columns by about 4.96–58.54 %. Owing to the protective effect of the reinforcement system, the development of tensile damage to the wooden columns was delayed, but the breaking location was still the column root. In addition, the energy dissipation capacity and equivalent viscous damping coefficient of the reinforced wooden columns were significantly improved. The deformation of the strengthened column root conforms to the plane section assumption, while the deformation of the reinforcement system was lagged due to the absence of colloid and shear connectors between the wooden column and the reinforcement system. A bending capacity equation for the reinforced wood column was deduced based on the strain distribution in the damaged section. The error between the calculated and experimental results was within 13 %.

FABRICATION OF AA1100/Fl2O3 COMPOSITE STRIPS AND THE IMPROVEMENT OF THEIR ELECTROMAGNETIC, MECHANICAL AND FRACTURE PROPERTIES

In this study, forming limit diagrams (FLDs), fracture toughness (FT), mechanical, magnetic, and electro-physical properties of Al/Fe2O3 composites have been investigated experimentally. Accumulative-roll-bonding (ARB) process was used to manufacture composite samples. Then, Al/Fe2O3 composites have been produced at 300∘C up to eight ARB passes. Also, magnetic composites have been fabricated with 0, 5% and 10[Formula: see text]wt.% of particles. The interlayer bonding quality was improved at higher passes. By studying the SEM rapture morphology, it was shown that the rapture mode changed to shear ductile for samples with more passes. For composite samples fabricated at higher passes and in comparison with the annealed sample, elongated dimples were turned to shallow dimples. FLDs area as the main forming criterion dropped severely after pass one and then began to improve at higher passes. Fracture test results showed that after the 8th pass, the value of FT improved gradually to the maximum value of 34.3[Formula: see text]MPam[Formula: see text].

Structural behavior of S-UHPC-S composite wall strips with waved tie bars: Experiment, simulation, and design

In this paper, novel steel waved tie bar shear connectors were developed in conjunction with ultra-high-performance-concrete (UHPC) core to obtain lightweight, high-strength, and easy-construction steel-UHPC-Steel (S-UHPC-S) composite structures. To study the structural behavior of S-UHPC-S composite wall panels with waved tie bars subjected to out-of-plane loads, seven 1/2 scaled S-UHPC-S composite beams were extracted and tested under three-point bending. Test variables included longitudinal and transverse reinforcement ratios, and shear span ratio. Experimental results indicated that S-UHPC-S composite beams failed in flexure mode under the shear span ratios of 2.5 and 3.5 and in flexure-shear mode under the shear span ratio of 1.5. Increasing the longitudinal reinforcement ratio from 1.0 % to 1.5 % and 2.0 % increased the peak load capacity of the S-UHPC-S composite beams by 16.5 % and 43.6 %, respectively, but increasing the transverse reinforcement ratio had a marginal effect on the load resistance because the S-UHPC-S composite beams were dominated by flexure or flexure-shear failure mode. Full-scale models were built with the finite element (FE) software LS-DYNA. After being validated with the test results, the FE model is used to conduct extended studies. Numerical results indicate that the contribution proportion of each component to the bending moment capacity of the S-UHPC-S composite beam can be sorted in a descending order, namely, steel faceplates > UHPC > ribs > tie bars. A method was proposed to predict the failure mode of the S-UHPC-S composite beams in accordance with shear span ratios and mechanical reinforcement ratios. Finally, computation methods for flexure strength and the maximum stud spacing were developed.

Microstructure and tribological behavior of Al–TiC composite strips fabricated by a multi-step densification method

This study aims to enhance the tribological properties of automotive applications by examining the effects of TiC content on the microstructure, mechanical properties, and wear behavior. This study investigates the production of Al–TiC composite strips using a novel multi-step densification process combining mechanical alloying and hot rolling with TiC concentrations ranging from 0 to 12 vol%. The novelty of this work lies in its comprehensive approach to developing and analyzing Al–TiC composite strips using a multistep densification method. This study integrates microstructural analysis, mechanical property evaluation, and detailed tribological behavior assessment under different wear loads (5–25 N). A key innovation is the application of the Abbott Firestone method to analyze worn surfaces, providing insights into optimal wear conditions. The study reveals that increasing the TiC content to 12 vol% significantly improves densification, hardness (up to 268.8% increase), and wear resistance (up to 95% improvement at a 5N load). Dry ball-on-flat sliding wear tests at loads of 5–25N demonstrate that TiC particles hindered complete delamination wear in the composite strips. The Abbott Firestone method analysis of worn surfaces indicated an optimal exploitation zone in the Al-6 vol% TiC composite at both low and high wear loads. This comprehensive approach provides valuable insights into optimizing Al–TiC composites for enhanced performance in automotive components that require improved wear resistance.

Evaluating the Success of Preformed Resin Bonded Composite Strip Crowns for the Primary Central Incisor in Restoring Carious Primary Canine Teeth: A Retrospective Analysis.

Background Restoration of primary canine teeth in pediatric dentistry requires a balance of functional, biological, and esthetic factors. Stainless steel crowns, while effective for posterior restorations, often have patient acceptance issues due to esthetic limitations. Resin-bonded composite strip crowns have gained traction for anterior restorations due to their superior esthetic qualities and repairability. However, their long-term performance in primary canines characterized by unique morphological and functional demands has not been thoroughly evaluated. This study investigates the efficacy of resin-bonded incisor strip crowns in primary canines over three years, assessing their functional durability, biological integrity, and esthetic performance to provide a comprehensive evaluation of their long-term success in this application. Methods This retrospective observational study, conducted from September 2023 to December 2023 at the Department of Pediatric and Preventive Dentistry, Saveetha Dental College and Hospitals, Chennai, Tamil Nadu, India, received ethical approval from the Institutional Human Ethical Committee (IHEC/SDC/PEDO-2103/23/131). Dental records from January 2020 to December 2020 were reviewed by two investigators to identify children aged six years or younger who had undergone pulpectomy in primary canine teeth and were restored with resin-bonded incisor strip crowns. Exclusions included records with missing contact details or post-treatment radiographs. The purpose was to ensure a three-year review period when contacting patients in 2023. Eligible parents were contacted by phone, informed about the study, and invited for a review. Informed consent was obtained in person. Children with exfoliated primary canines and those whose parents did not sign the consent form were excluded. The restored crowns were evaluated using World Dental Federation (FDI) criteria across functional, biological, and esthetic domains by two calibrated examiners. Statistical analysis was conducted using IBMSPSSStatistics for Windows, Version 24 (Released 2016; IBM Corp., Armonk, New York, United States), with categorical variables expressed as n (%), inter-examiner reliability assessed by Cohen's kappa, and chi-square test used for goodness of fit, setting significance at 95%. Results Of the 92 primary canines restored with resin-bonded incisor strip crowns, 60 children were evaluated. The retention rate at the three-year follow-up was 50 (83.3%). Functional evaluation revealed that 48 (80%) of crowns maintained surface texture, 42 (70%) preserved form and contour, and 52 (86.6%) demonstrated acceptable occlusion and wear. Biologically, 55 (91.7%) of the crowns had no secondary caries, and 56 (93.4%) had no dental hard tissue defects at the margin. Esthetically, 48 (80%) of crowns retained surface texture, 46 (76.6%) had a satisfactory color match, and 45 (71.6%) exhibited minimal marginal staining. Statistical analysis confirmed significant results for all functional and esthetic parameters (p < 0.05). Conclusion The technique of placing incisor strip crowns in the place of primary canines can be recommended considering its maintenance of functional, biological, and esthetic properties.

Effect of ARB process on the plane stress fracture toughness, creep properties and forming limit diagram of Aluminum/BN/Copper composite strips

Abstract In the present study, Al/BN/Cu bimetal composite strips were fabricated via the accumulative roll bonding (ARB) process. Then, fracture toughness, mechanical properties, bonding strength, forming limit diagram (FLD), and creep properties have been studied via experimental techniques. The study of creep behavior and mechanical properties showed a formation of a 17 μm atomic diffusion layer at the interface during ARB under three creep loading conditions namely 35 MPa at 225 °C, 35 MPa at 275 °C, and 30 MPa at 225 °C. The tensile strength of samples improved to 144 MPa which was about 234% in comparison with the primary Al monolithic sample. It was observed by the SEM that the fracture types changed to shear kind after higher passes including prominent effects on the fracture morphology. FLD curve dropped severely after the first ARB pass and then began to enhance at higher passes. The fracture toughness value of 30 MPa m1/2 was achieved after ten ARB passes. An intermetallic composition was created near Al. The creep failure time did decline by 44% and the stress level decreased by 13% at a constant temperature. It can be concluded that applied temperature and stress effect on creep properties especially leads to increasing the slope of creep curves with higher stresses. This trend was opposite for the creep temperature at higher temperature levels. Moreover, dynamic recrystallization was observed through the crystalline structure of samples.

A variable kinematic multi-field model for lamb wave propagation analysis in smart composite panels

The study explores the propagation of symmetric and antisymmetric fundamental Lamb waves in laminated composite strips, employing multi-field piezo-elastic plate models. The findings indicate the necessity of employing higher-order kinematic models to enhance the accuracy of wave propagation assessments. To further optimize computational efficiency, node-dependent kinematic models are utilized. The research delves into the tradeoff between reducing computational costs and maintaining result accuracy demonstrating a reduction of up to 60% in computational expenses in simple models while keeping the error below 1%. Two-dimensional wave propagation in laminated composite plates was further considered, expanding the scope due to material orthotropy.

Moving crack caused by SH-wave propagating in a composite strip under distinct loading constraints

Moving crack caused by SH-wave propagating in a composite strip under distinct loading constraints

Effect of Surface Roughness on the Properties of Ag/Cu Composite Strips

Effect of Surface Roughness on the Properties of Ag/Cu Composite Strips

Piezoresistive properties for soft structures using hybrid CCB/CNT-based natural rubber latex composites

This study explores the development of flexible sensors for soft structures. Conductive carbon black (CCB) and carbon nanotubes (CNT) were incorporated into a natural rubber (NR) matrix using glutaraldehyde (GA) as a curing system. The sensor properties of latex-NR composites with 20 phr of CCB, including variations of CNT content (0.5 to 3 phr), were examined. Increasing CNT content beyond 0.5 phr decreased tensile strength and elongation at break, but improved sensitivity and gauge factor (GF). Additionally, applying a voltage over 5 V caused a joule heating of the latex-NR composite strip elements. When integrated onto a soft tendon-based TPU bending actuator, higher CNT content reduced electrical signal drift during cyclic bending, enhancing long-term monitoring. This research highlights the potential of CCB/CNT-based latex-NR composites for soft structure applications, including soft robotics and health monitoring.

Advanced feature extraction for the characterization of impact events on composites using multiresolution wavelet-based simulations

The detection and characterization of impact events on composite structures from the induced wave responses, involves many challenges. Coexisting guided waves of high dispersive nature propagate after impact, entailing continuous time variations in their wavenumber, frequency and group velocity content, which complicate the exact estimation of the time-of-flight and the extraction of impact characteristics. A multiresolution finite wavelet domain computational method, combined with appropriate contact laws, is presented to provide enhanced simulation and characterization capabilities of impact events. An explicit multiresolution time integration scheme involves a coarse solution, followed by finer solutions that are sequentially added to the coarse one, until convergence is achieved. The hierarchical character of the approach makes the impact simulation very fast and accurate. Moreover, due to the filtering properties of Daubechies wavelet functions, each resolution component effectively models and isolates specific wavenumber spectra, providing the capability to separate coexisting wave modes, and to overcome difficulties imposed by the dispersive nature of the resultant guided waves. It is demonstrated that the multiresolution simulation can reveal wave characteristics and time-of-flight features that no other traditional single-resolution method can do, and provides the basis for the development of powerful inverse methods that can localize the impact and characterize the impactor parameters. The method is first applied on impacted composite strips and the structural responses of each resolution component are assessed in order to obtain the desired features for impact location estimation and characterization. Finally, the method is implemented on an impacted composite plate structure and the various wave characteristics simulated by the fine components are presented, evincing the advanced features that the proposed method provides.

Numerical simulation of aluminum-steel clad strip production using horizontal single belt casting process

A 3-D steady-state turbulent flow and solidification model was developed to simulate melt flow in a Horizontal Single Belt Caster for the production of an Al-Steel composite strip. The steel substrate is attached to the moving belt and moves at the same speed as the belt while the aluminum melt is introduced onto the substrate via an extended nozzle melt delivery system. A finite volume method was used to numerically solve the governing equations. In order to model the turbulent flow, a low Reynolds k − ε turbulent model was adopted. The developed numerical model was further employed to investigate the effect of such parameters as clad thickness, casting speed, molten aluminum superheat, and heat extraction rate from the belt surface on fluid flow and temperature fields in the system. It was found that for a certain clad thickness, casting speed and cooling rate should be adjusted properly and outlet strip temperature is independent of Inlet melt superheat.

Magnetic polyurethane based composites as contactless valves in microfluidic applications

Magnetoactive polymer composites have garnered significant attention for their potential use in diverse applications, owing to their rapid and reversible response to external magnetic fields. By incorporating magnetic nanoparticles (MNPs) into an elastomeric matrix, these composites exhibit unique properties under static or alternating magnetic fields. In this context, thermo-polyurethane-based magnetic active composites are promising materials for developing microfluidic system components such as valves and peristaltic pumps. In the current study, we investigated the utilization of cobalt ferrite (CoFe2O4) magnetic nanoparticles in conjunction with a non-toxic synthesis method for polyurethane. It was explored the impact, on the overall success of the process, of cobalt ferrite nanoparticles incorporation at various stages of the thermo-polyurethane (TPU) synthesis reaction. Finally, the effects of different amounts of MNPs on the physicochemical properties of the resulting composites and their behavior as actuators under the influence of a magnetic field, was investigated. Our studies reveal that the actuator response of the composites increases proportionally with the percentage of MNPs present.Finally, the performance of a TPU/7.5% (V/V) CoFe2O4 composite strip as a flow control actuator within a microfluidic system was evaluated. This actuator responds to magnetic fields by bending, resulting in a 10% reduction in flow rate of microfluidic system. Reversing the magnetic field restores the flow rate to its initial value. Our cyclic tests illustrate the actuator's capacity to locally and temporarily modulate the microfluidic system's resistance. When combined with tailored TPU elasticity, these materials show significant potential for the fabrication of microfluidic valves and pumps.

Gingival health, plaque accumulation, and restoration outcomes in deciduous anterior teeth: evaluating zirconia crowns versus composite resin strip crowns.

Zirconia crowns, resembling crystals and with enamel-like aesthetics, are recent entrants in pediatric restorative dentistry. Despite growing use, their empirical efficacy remains under-explored. The aim of this study is to compare resin composite strip crowns and premanufactured zirconia crowns on primary maxillary incisors. In the Pediatric Dental Clinics, 240 primary maxillary incisors (69 patients) were treated with either zirconia (120 teeth) or composite strip crowns (120 teeth). Evaluations of gingival health, plaque, secondary caries, restoration failure, and opposing teeth wear occurred at 3, 6, and 12-month intervals. At 3 months, zirconia crowns showed less gum bleeding (P=0.006) and plaque. Through 6 and 12 months, zirconia crowns exhibited fewer failures but higher opposing teeth wear. Strip crowns indicated greater tooth material loss. Zirconia crowns demonstrated superior gingival health and durability over composite resin strip crowns but caused increased wear on opposing teeth.

Formation of High Hardness ZnO/Cu Nanocomposite by Thermal Oxidation from Cu-Zn Alloy Strips

Due to their superior thermal, electrical, and mechanical properties, brass and Cu-Zn alloys are widely used in a broad range of applications. In applications requiring greater durability, corrosion resistance, and wear resistance, however, the ZnO/Cu composite is preferable. Typically, ZnO/Cu composites are manufactured through powder metallurgy. In this article, brass strips are thermally oxidized in an oxygen atmosphere to produce ZnO/Cu composite strips. The optimal temperature and oxygen pressure are 600–650 °C and less than one atmosphere, respectively. The homogeneous distribution of nanoscale ZnO clusters in the Cu matrix can be attributed to the diffusion of both Zn and O in the matrix. In addition, the composite is substantially harder than brass, increasing from 70–90 HV to 200–240 HV. Therefore, thermal oxidation has been shown to be a simple and cost-effective process for producing ZnO/Cu composites with high hardness.

Enhanced Magnetoimpedance Effect in Co-Based Micron Composite CoFeNiSiB Ribbon Strips Coated by Carbon and FeCoGa Nanofilms for Sensing Applications.

Quenched Co-based ribbon strips are widely used in the fields of magnetic amplifier, magnetic head material, magnetic shield, electric reactor, inductance core, sensor core, anti-theft system label, and so on. In this study, Co-based composite CoFeNiSiB ribbon strips with a micron width were fabricated by micro-electro-mechanical systems (MEMS) technology. The carbon and FeCoGa nanofilms were deposited for surface modification. The effect of carbon and FeCoGa nanofilm coatings on the crystal structure, surface morphology, magnetic properties, and magnetoimpedance (MI) effect of composite ribbon strips were systematically investigated. The results show that the surface roughness and coercivity of the composite ribbon strips are minimum at a thickness of the carbon coating of 60 nm. The maximum value of MI effect is 41% at 2 MHz, which is approximately 2.4 times greater than plain ribbon and 1.6 times greater than FeCoGa-coated composite ribbon strip. The addition of a carbon layer provides a conductive path for high frequency currents, which effectively reduces the characteristic frequency of the composite ribbon strip. The FeCoGa coating is able to close the flux path and reduce the coercivity, which, in turn, increases the transverse permeability and improves the MI effect. The findings indicate that a successful combination of carbon layer and magnetostrictive FeCoGa nanofilm layer can improve the MI effect and magnetic field sensitivity of the ribbon strips, demonstrating the potential of the composite strips for local and micro area field sensing applications.

Stiffness of reinforced concrete structures under bending considering shear and axial forces (part 2)

The paper presents a physical and computational model for determining the parameters of limit states of reinforced concrete structures under complex stressed state - bending with axial and shear forces. Based on the adopted scheme of cross-section discretization and A.R. Rzhanitsyn's theorem of duality between force and deformation parameters, the forward and backward transfer for determining the coefficients of the stiffness matrix of reinforced concrete rod structures with inclined and normal cracks have been constructed. Stiffness of structures in the zone of inclined cracks is determined using the model of composite strips which separate the zone with inclined cracks. The hypothesis about the character of deformation distribution in a complex-stressed reinforced concrete element with inclined cracks is accepted.For this model the conditional shear modulus is obtained, which allows to determine the average relative linear and angular strains of concrete and reinforcement at the point adjacent to the shear joint between inclined cracks. Based on this model and using the experimentally obtained value of the relative shear in the inclined crack, the dowel forces in the reinforcing bar intersected by the inclined crack were determined. The application of the obtained analytical relationships in the practice of designing reinforced concrete structures allows not only to clarify significantly the definition of displacements and width of opening of inclined and normal cracks, but also to maximize the convergence of the design and physical model based on experimental data.

Definition of the stress-strain state of a glued laminated timber beam reinforced with composite strips using experimental method

The trend in the development of the construction industry worldwide requires increasing attention to ecological aspects, which means that materials with minimal negative impact on the environment are becoming increasingly popular. At the same time, these materials must possess high strength and durability against various external influences and loads. From this perspective, constructions made of wood and its derivatives are gaining the most popularity. Such constructions, made from renewable natural resources, exhibit relatively high strength at relatively low density, thus belonging to such materials. Although wood has its drawbacks, such as susceptibility to drying, rotting, and anisotropy of properties, these drawbacks can be completely mitigated in glued laminated timber structures. Glued laminated timber beams, which are the primary structural element of many buildings and structures, are the most widespread. Therefore, the issue of significantly increasing their rigidity and strength through reinforcement with composite materials is particularly relevant. This article proposes a methodology for determining the stress-strain state of a glued laminated timber beam reinforced with composite strips. The results include deformation parameters of the experimental model, actual elastic modules during bending, maximum longitudinal stresses at the center of the span, along the load application axis, and along the support axis. Additionally, maximum transverse and shear stresses along the load application axis and along the support axis are determined. The actual maximum load-bearing capacity of the experimental model reinforced with composite strips is established.

EVOLUTION OF WEAR AND CORROSION RESISTANCE OF Bi ALLOY-LAMINATED Al/TiO2 COMPOSITE STRIPS FABRICATED VIA APB PROCESS

In this study, Bi alloy AA1100/TiO2/AA5083 composites were produced by accumulative press bonding (APB) for the first time. In the first step, two bars of aluminum alloys 1100 and 5083 with 5[Formula: see text]wt.% of uniformly scattered TiO2 particles were stacked together and pressed with a 50% reduction ratio. Then, this process was continued up to six steps. Corrosion properties of composites were studied by potential dynamic polarization and electrochemical impedance spectroscopy measurement in 3.5[Formula: see text]wt.% NaCl solution. So, in this investigation and as its novelty, a considerable improvement was revealed in the main electrochemical parameters as a result of enhancing the influence of APB steps and the inert character of the particles. Moreover, using the wear test, the wear resistance of these bi alloy composites has been studied vs the APB steps. Also, the wear and electrochemical experiments showed that corrosion and wear resistance of samples were improved by the APB steps by 70% and 34%, respectively.