Strength Materials Research Articles

Impact of Strength Parameters and Material Structure of Bone Plates on Displacement of Bone Fragments in the Injured Area

The study is a metallographic analysis of commercial bone plates used for stabilizing long bones. The plates examined were delivered to the hospital in different years, and the course of treatment of patients with similar goniometric and anthropometric parameters varied dramatically. To determine the characteristics of displacement of bony fragments in the area of the simulated fracture and relate it to the strength parameters of the bone plate, experimental tests were carried out on composite femurs loaded according to the biomechanical loading model at known values of forces acting on the femoral head. In order to assess the influence of material parameters of the plate on the biomechanics of the bone–bone plate system, microstructural and strength tests were performed, i.e., three-point bending tests, chemical composition and hardness assessments, as well as evaluation of the state of internal stresses in the tested materials. The research conducted allowed us to develop guidelines for companies producing bone fixations and orthopedic surgeons who use bone plates to stabilize bones after mechanical trauma, allowing the plates to be tailored to individual patient characteristics.

Boron nitride nanotubes induced strengthening in aluminum 7075 composite via cryomilling and spark plasma sintering

Al7075 is among the strongest commercial aluminum alloys with low density, making it a standout choice for structural metals. However, the never-ending quest for higher strength and low-density materials demands structural metals stronger than Al7075. In this study, high-strength and chemically inert one-dimensional boron nitride nanotubes (BNNTs) are used to reinforce Al7075 alloy, making ultra-high strength aluminum matrix composite. Al7075-BNNT composite is fabricated using a multi-step process involving ultrasonication, cryomilling, and spark plasma sintering (SPS). Ultra-fine grains were efficiently achieved in 2 h of milling, resulting in an impressive ultimate strength of ~ 636.8 ± 18.9 MPa and elongation up to necking of 10.1 ± 0.5% in heat-treated Al7075-BNNT composite. The obtained strength is 1.3 times higher than SPS Al7075 and 2.9 times higher than cast Al7075 alloy. The cryomilling facilitated a homogeneous dispersion of BNNTs, fostering effective interfacial bonding, albeit leading to variations in BNNT length ranging from 1–50 µm. The interplay between BNNT lengths and their impact on mechanical properties is explored, showcasing a synergistic improvement in strength and elongation. The comprehensive understanding of the resulting strengthening mechanisms encompasses Hall–Petch, Orowan, dislocation-induced strengthening, and dominant load transfer mechanisms. These findings offer valuable insights into fabricating high-performance aluminum matrix composites surpassing conventional strength. The Al7075-BNNT composite's unprecedented mechanical strength could further extend the use of aluminum alloys to more demanding aerospace applications, such as spacecraft structures and next-generation vehicles, as well as racing and automotive parts where the need for ultra-lightweight yet ultra-strong materials is paramount for fuel efficiency and performance under extreme conditions.

Lightweight Aluminum Alloy for Energy Saving Green Vehicle

This study is devoted to the development of lightweight Aluminum alloy to reduce energy consumption and environment pollution in automobile sector. Aluminum alloy shows impressive strength though they are lightweight. The effect of Cu on Al-5.5Zn-2.5Mg-xCu alloy has been studied and improvement in mechanical properties within a range has been observed. The optical microstructure confirmed the formation of Cu enriched brittle phase by solid solution strengthening and it accelerates the hardness and tensile strength. After certain limit strength followed the opposite trend so the material can be used as high strength material when the Cu content will be in a certain limit. In automobile sector vehicle parts made with this alloy material has less weight than commonly used steel. The total weight reduction of a vehicle will reduce the energy consumption which will ultimately eliminate the emission of environment pollutant gas

Experimental Study on Flexural Behaviour of Prefabricated Steel-Concrete Composite I-Beams Under Negative Bending Moment: Comparative Study.

The issues of numerous steel beam components and the tendency for deck cracking under negative bending moment zones have long been challenges faced by traditional composite I-beams with flat steel webs. This study introduces an optimized approach by modifying the structural design and material selection, specifically substituting flat steel webs with corrugated steel webs and using ultra-high-performance concrete for the deck in the negative bending moment zone. Three sets of model tests were conducted to compare and investigate the influence of deck material and web forms on the bending and crack resistance of steel-concrete composite I-beams under a negative bending moment zone. The findings indicate that, compared to a conventional steel-normal concrete composite I-beam, incorporating ultra-high performance concrete into the negative bending zone enhances the cracking load by 98%, resulting in finer and denser cracks, and improves the ultimate bearing capacity by approximately 10%. In comparison to the composite I-beam with flat steel webs, the longitudinal stiffness of the composite I-beam with corrugated steel webs is smaller, which can further enhance the bridge deck's resistance to cracking in the negative bending moment zone, and maximize the steel-strengthening effect of the lower flange of the steel I-beam. Based on the findings of this study, it is recommended to use steel ultra-high-performance concrete composite I-beams with corrugated steel webs due to their superior crack resistance, bending strength, and efficient material utilization.

Life as a Design Element of Hardened Urban Shorelines

Armored urban shorelines have historically impoverished life on the waterfront. Materials and forms were chosen to discourage the settlement of marine communities and human access. This has weakened shoreline habitats and adjacent terrestrial and aquatic ecosystems and diminished urban human experiences by reducing links to nature. Augmentation of existing structures and new waterfront designs for specific ecological goals such as salmon habitat improvement are reversing these trends. With the integration of advances in ecology, social science, engineering, architecture, and regulation, urban shorelines can be designed and built to enrich human experience and natural resources through connections rather than through separation and can then be considered “living shorelines.” Such a holistic approach should extend from the subtidal to the terrestrial vegetated and built environment. As with traditional soft sediment living shorelines, life can be included from the outset and be applied as an integral design element providing many functions as well as ecosystem services and social well-being benefits. We present challenges and recommend solutions for broad incorporation of this new vision for urban shorelines. We need data on biological recruitment processes, a better understanding of human social engagement with the urban shore, and continued development of materials for strength, customizability, ecosystem compatibility, and reduced carbon footprint. Measuring and tracing impacts or contributions will be difficult. Improved assessments of investment risk and reward for urban areas are needed to fund these efforts, and regulatory adaptability is needed to allow the transformation of urban shores into living shores.

Experimental and numerical analysis of pGFRP and wood cross-arm in latticed tower: a comprehensive study of mechanical deformation and flexural creep

The adoption of pultruded glass fibre-reinforced polymer (pGFRP) composites as a substitute for traditional wooden cross-arms in high transmission towers represents a relatively novel approach. These materials were selected for their high strength-to-weight ratio and lightweight properties. Despite various studies focusing on structures improvement, there still have a significant gap in understanding the deformation characteristics of full-scale cross-arms under actual operational loads. Existing study often concentrate on small coupon scale and laboratory condition, leaving a gap in understanding how the cross-arm behavior in full-scale acting on actual weather condition. This study aims to investigate the load-deflection and long-term creep behavior of a pGFRP cross-arm installed in a 132 kV transmission tower. The pGFRP cross-arm was load-tested on a customized rig in an open environment. Using the cantilever beam concept, deflection was analyzed and compared to wood cross-arms. Finite element analysis validated results, and long-term deformation under high-stress loads was assessed. The pGFRP cross-arms showed lower deflection at working loads compared to Balau wood, due to the latter’s higher elastic modulus and flexibility specifically at Point Y3, the critical issues necessitated reinforcement strategies. pGFRP cross-arms withstood higher bending stress, showing 32% less deflection under normal conditions and 15% less under broken wire conditions than Balau wood. Additionally, the creep strength of wood was 34% lower than that of pGFRP cross-arms. Besides that, the pGFRP cross-arm have highest elastic modulus than Balau-wood, shows that the composite cross-arm have better structural strength, resisting deformation and higher flexibility materials. Finite element analysis (FEA) confirmed these results with the relative error between them less than 1%. Consequently, the investigation into pGFRP cross-arm deformation behavior in this paper serves as a foundational framework for future research endeavors specifically for high transmission tower and other structural application.

EUROPEAN CONCRETE ROAD STANDARDS AND PRACTICES

The scientific article "European Concrete Road Standards and Practices" by Raymond Sharp provides a comprehensive overview of the current standards and practices in the construction of concrete roads across Europe, focusing on twelve countries: Austria, Belgium, Czechoslovakia, Denmark, France, Great Britain, Italy, the Netherlands, Spain, Sweden, Switzerland, and West Germany. The research synthesizes data from the Permanent International Association of Road Congresses (PIARC) and the European Cement Association, including detailed synoptic tables prepared for previous European symposia on concrete roads. This study delves into the various factors influencing pavement design, including traffic levels, sub-grade strength, and pavement materials, discussing the complexities of predicting future traffic and the insensitivity of pavement costs to small traffic variations. It examines the philosophical and economic decisions that guide pavement thickness and highlights the standardization in pavement design across different nations, emphasizing the small changes in design thickness due to the proven success and economic efficiency of existing systems. Furthermore, the paper explores the influence of non-technical factors such as governmental policies and competition between construction methods on pavement design. It also discusses the impact of local material availability and construction practices on the cost and quality of road construction. The research concludes that while concrete pavements generally perform well and offer long life spans, there are multiple viable approaches to pavement design influenced by local conditions and historical practices. It suggests that imposing a uniform design approach across different environments and traditions is impractical, advocating for flexible, context-specific solutions in pavement engineering. (Abstract generated by AI tool ChatGPT 4)

Analyzing the inelastic response of wind-excited steel tall buildings through a reduced-order model incorporating strength and stiffness degradation along with P-Delta effects

Analyzing the inelastic response of wind-excited steel tall buildings through a reduced-order model incorporating strength and stiffness degradation along with P-Delta effects

Fabrication of superporous cryogels with amidoxime chelation sites and customizable 3D printing for targeted palladium recovery from secondary resources

Recovering precious metals such as palladium from secondary resources faces significant challenges, including the scarcity of efficient adsorbents capable of withstanding harsh acidic conditions and needing materials with high selectivity, mechanical stability, and scalability. In response to these challenges, we developed highly porous cryogels functionalized with sulfonic and amidoxime groups, achieving a unique combination of hydrophilicity, flexibility, and selectivity for Pd(II) ions. Using a redox cryopolymerization method, these cryogels attained a gel fraction of 100% and a maximum adsorption capacity of 425.3mgg-1 at 318K, as the Langmuir isotherm model fitted. This work also combined 3D printing technology with cryopolymerization to create a highly selective, high mechanical strength and customizable shape adsorption material, overcoming traditional adsorption materials' limitations in acid conditions. This innovative combination fills the gap in selective palladium recovery in customizable super macroporous materials, offering a sustainable solution for precious metal recovery and setting a foundation for broader applications in adsorption separation.

Enhancement of 316 L stainless steel mechanical properties through TiC particle introduction via metal powder injection molding

Abstract Metal powder injection molding (MIM) has been a popular technique in production of alloy materials. Through this technique, near-net-shape alloy products can be molded with one-step production. Stainless steel 316 L (SS 316 L) is an important material in aerospace and marine industry for its excellent material strength and resistance to corrosion. As the industry grows with upgraded techniques, the standard for next generation material strength has improved tremendously. Here we present a practical method strengthening SS 316 L via MIM technique, which might provide a pathway for exploration of high strength materials. TiC was introduced into SS 316 matrix with polyoxymethylene (POM) binder. The metallography indicates that the introduction of TiC facilitates the refinement of the 316 L grain. As the TiC content increases from 0 wt% to 3 wt%, the material properties improve significantly, including a rise in hardness from 151 HV to 301 HV, tensile strength from 689 MPa to 792 MPa, and yield strength from 221 MPa to 339 MPa. Additionally, there is a noticeable reduction in the coefficient of friction and the wear cross-section.

Preparing controlled low strength materials with cement-treated construction waste clay improved by sodium hexametaphosphate.

To solve the disposal of large quantities of construction waste clay, this study proposes a new method for preparing controlled low strength materials (CLSM). Flow tests, unconfined compressive strength (UCS) tests, hydraulic conductivity tests and scanning electron microscope (SEM) analyses were performed on cement-treated construction waste clay with different additive content (e.g. sodium hexametaphosphate (SHMP), water glass, and phosphogypsum (PG)). The influence of additive content on the mechanical and microstructural properties of cement-treated clay-based CLSM was analyzed. The results indicated that the SHMP greatly enhanced the flowability of samples, adding 1%SHMP increased the fluidity of the sample by more than 80%, whereas 5% water glass had negligible effect. Additionally, the 10% PG improved the flowability retention, making it have higher flowability after 30 mins (more than 200 mm). SHMP interacted with Ca2+, significantly influencing the cement hydration; notably, 1% content resulted a notable reduction of samples from 167.5 kPa to 21.5 kPa at 1 day. Although increasing SHMP content improved the early strength, it led to a decrease in later strength, with the maximum late strength observed at 2% SHMP. Both PG and water glass also contributed to late strength enhancement, though higher SHMP levels diminished their effects. While SHMP markedly improved permeability resistance (less than 8 × 10-8 cm/s after 28d), hydraulic conductivity showed minimal variation with increased dosage. The combination of SHMP, PG and water glass effectively enhances the flowability and strength of clay-based CLSM at low water content, solving the contradiction between fluidity and strength. This promotes the sustainable development of green building materials.

The effect of SiC and Y2O3 inclusion on microstructure and mechanical properties of Al 5052 composite fabricated through Friction Stir Process.

A consistent research attempt to develop newer lightweight-high strength materials facilitates the automobile sector to excel in product efficiency. The present research is another endeavour to anchor the automobile industries by exploring novel composite. The different earth elements SiC and Y2O3 are utilised for the hybrid reinforcement of Al 5052 alloy in four different weight proportions. Friction Stir Processing (FSP) is employed to fabricate composites. The microstructure analysis conducted through the optical microscope reveals the formation of fine grain size at the nugget zone. The effect of dynamic recrystallization and particulate strengthening is reflected in the inflated tensile strength of Al-3SiC-1Yo. The microhardness test results manifest the higher hardness at the nugget zone and descending to the Heat Affected Zone (HAZ) through the Thermo Mechanically affected zone (TMAZ). The post-tensile fracture morphological observation through Scanning Electron Microscopy (SEM) explores the particulate strengthening mechanisms offered by the piled-up dislocation densities. The hybrid hard particle inclusion in the matrix helps to achieve 63.87 %, 50 % and 35 % improvement in tensile strength, hardness and impact toughness of SiC and Y2O3 reinforced FSPed Al alloy. Further, a higher level of inclusion of Y2O3 beyond 0.5 % is found to dent the properties due to the agglomeration effect of Y2O3 particles.

A Review on Selecting material suitable for a statically loaded thermal conductor using the TOPSIS Method

It is crucial to choose the right material for a permanently attached heat conductor since it has an impact on the performance, security, and efficacy of thermal management platforms. Key ideas and the significance of the research are highlighted in this description of the selecting process. Determine the suitability of a material by taking into account its thermal conductivity, mechanical strength, temperature resistance, corrosion resistance, cost-effectiveness, ease of manufacture, and environmental impact. Effective heat transfer is guaranteed by optimal thermal conductivity, while structural integrity under consistent stresses is guaranteed by mechanical strength. The substance must be corrosion-resistant in the required conditions and tolerate the anticipated temperature range. Decision-making is also influenced by factors including cost, production requirements, and environmental sustainability. Thermal conductivity, mechanical strength, and overall material efficiency can all be improved through research and material optimisation. The focus of research is on enhancing productivity, security, innovation, and sustainability across a range of businesses that depend on efficient thermal management.

Multiplane vs. Single-Plane FDM Printing: A Study on Mechanical and Physical Properties of the PET-G

The dynamic landscape of additive manufacturing is rapidly evolving, with the fusion of fused deposition modelling (FDM) and multiplane printing emerging as a transformative technique for creating intricate 3D PET-G components. Utilizing a cutting-edge gantry-style FDM apparatus, this comprehensive research endeavour centred on the fabrication and subsequent meticulous evaluation of multiplane samples. These were contrasted against their single-plane counterparts, focusing on pivotal metrics such as tensile strength, flexural resilience, and inherent material density. The findings were enlightening: Multiplane samples exhibited marked superiority in tensile attributes, whereas the single-plane samples displayed pronounced advantages in flexural strength and overall density. Such distinct variations offer profound insights into the overarching influence of multiplane printing techniques within FDM processes. This investigative foray not only underscores the vast potentialities of multiplane printing but also signals its instrumental role in heralding future innovations within the expansive and multifaceted domain of additive manufacturing.

Controlled low strength material modified with lignosulfonate

Controlled low-strength materials (CLSM) have been used for conventional backfilling and structural filling owing to their flowability, self-consolidating, and self-leveling features. This study investigates the rheological, mechanical, and dynamic characteristics of lignosulfonate-modified CLSM. The elemental analysis of lignosulfonate reveals the presence of various elements and an irregular morphology, as observed using a scanning electron microscope. A series of tests, including flow tests, Vicat needle tests, uniaxial compression tests, and shear wave monitoring, are conducted to evaluate the flowability, setting time, strength, and shear wave velocity of lignosulfonate-modified CLSM. The experimental results show that the flowability and initial and final setting times of the CLSM mixtures increase with increasing lignosulfonate content (LC), which improves workability in the field but results in a slight strength loss. Regarding the uniaxial compressive strength, CLSM mixtures with lower LC exhibit a rapid increase in strength during the early stages, while those with higher LC show higher performance on the 14th day of curing. In contrast, an LC of 0.21% led to a slight reduction in the strength on the 28th day. The current study also shows an exponential correlation between the uniaxial compressive strength and shear wave velocity.

UTILIZATION OF ALUMINA AND STEEL INDUSTRIAL WASTE FOR THE DEVELOPMENT OF CONTROLLED LOW STRENGTH MATERIALS

The study aimed at incorporating Red Mud, a byproduct of bauxite ore extraction, and Ground Granulated Blast Furnace Slag (GGBS), a byproduct of the steel industry, into Controlled Low Strength Materials (CLSM). These materials were combined with M Sand and cement to develop a sustainable and cost-effective construction material. Utilizing Red Mud and GGBS addresses waste disposal challenges while enhancing CLSM properties, making it a more environmentally friendly option. By converting industrial byproducts into valuable construction components, the research contributes to sustainable development and the circular economy. The research methodology involves creating five different dry mix combinations, varying the proportions of Red Mud, GGBS, M Sand, and cement. Each combination was tested with four different water contents to evaluate their engineering and dynamic properties. This methodical approach was focused to identify the optimal mix that balances strength and workability. By analyzing these properties, the study provided a valuable insight into the behavior of CLSM under various conditions, contributing to the advancement of more efficient construction materials. The systematic testing ensured that the developed CLSM mixes met the necessary performance criteria for practical applications. The primary objective of the study was to develop a phenomenological model based on the obtained strength and flow values. This model will serve as a predictive tool for future research, aiding in the design of CLSM mixtures with desired characteristics. By demonstrating the feasibility of using Red Mud in CLSM, the research underscores its potential to offer cost-effective and sustainable solutions for various engineering applications. This innovative approach not only promotes waste utilization but also opens new possibilities for improving construction practices. The developed model will help engineers and researchers predict the performance of new CLSM formulations, streamlining the development process for future projects.

The use of normative models under combined compression and bending for verification of concrete-filled steel tubes with high strength materials

Buildings have been demanding increasingly slender pillars from projects, consequently increasing the demand for efficient and economical solutions. One of the solutions adopted is the use of high-strength concrete and steel and the optimization of sections for filled mixed tubular pillars, which has been widespread in European, American, and Asian countries; however, there is little application in Brazil's constructions. Verification of mixed pillars under flexo-compression can be done by simplified methods or analytical methods such as the method of deformation compatibility. The draft revision of ABNT NBR 8800:2023 introduces three simplified calculation models for flexo-compression verification, with limitations in its application for concrete with characteristic compression strength below 50 MPa and steel profile with yield strength below 450 MPa, as well as proposing polygonal lines to trace interaction curves. In this article, the simplified calculation models from the draft revision of ABNT NBR 8800:2023 are compared with experimental results from the literature of prototypes of circular tubular filled mixed pillar sections with concrete strength above 50 MPa and steel profile with yield strength above 450 MPa. For this purpose, a computational tool was developed in MATLAB that traces the interaction curves of the draft revision project of ABNT NBR 8800:2023. The suitability and conservatism of simplified methods were verified when using high-strength materials outside the normative range.

Mechanical, machinability and water absorption properties of novel kenaf fiber, glass fiber and graphene composites reinforced with epoxy

This paper aims to fabricate a novel kenaf fiber, glass fiber, graphene composite reinforced with epoxy, and to study its water absorption, mechanical and machining properties. Natural fiber composites seek numerous applications nowadays due to its high strength is to weight ratio, high impact resistance, thermal stability, and recyclability. The literature study on natural fiber composites indicates lack of research on Kenaf fibers reinforced with E-glass fibers in conjunction with 0.5% and 1.0% of graphene. Hence, this research focuses on Kenaf fiber with percentage composition of graphene was varied as 0.5%, and 1.0%, by weight of the holding matrix and with/without incorporation of glass fiber. Suitable surface modifications were done by treating natural fibres by 0.5% NaOH for better adhesion of fibre and epoxy resin. Sonication and Cetyl trimethyl ammonium bromide (CTAB) treatments were also done to realize the fine scattering of graphene in the epoxy matrix in order to achieve better mechanical behaviour. Moulds were prepared as per D-638 ASTM standards. The treated fibres were then arranged in the mould by the conventional hand layup technique. The main objectives of this study are to conduct tensile, flexural, Impact, water absorption, machinability, and FTIR test. Result shows that the incorporation of graphene in natural fiber composites showed an increase in tensile strength, flexural strength, and water absorption properties by 27.7%, 53%, and 15% on average, respectively. The composites used in this research find their use in potential applications such as defence, biomedical aids, automobiles, packaging, actuators, etc. These often generate great interest, whenever there is a demand for fabricating lightweight and high strength material.

Development and Characterization of Sustainable Cement-Free Controlled Low Strength Material Using Titanium Gypsum and Construction Waste Soil.

This study investigates the utilization of titanium gypsum (TG) and construction waste soil (CWS) for the development of sustainable, cement-free Controlled Low Strength Material (CLSM). TG, combined with ground granulated blast furnace slag, fly ash, and quicklime, serves as the binder, while CWS replaces natural sand. Testing thirteen mixtures revealed that a CWS replacement rate of over 40% controls bleeding below 5%, with a water-to-solid ratio between 0.40 and 0.46, ensuring flowability. Higher TG content reduces flowability but is crucial for strength due to its role in forming a crystalline network. Compressive strength decreases with higher TG and water-to-solid ratio, while 3-5% quicklime provides a 56 day strength below 2.1 MPa. Higher CWS reduces expansion, and TG content between 60% and 70% minimizes volume changes. XRD and SEM analyses underscore the importance of controlling TG and quicklime content to optimize CLSM's mechanical properties, highlighting the potential of TG and CWS in creating low carbon CLSM.

Advantages and feasibility of prefabricated PEEK crowns for aesthetic restoration in primary teeth

Objectives The main purpose of this study is to evaluate the efficacy of polyetheretherketone (PEEK) as a material for prefabricated crown restorations in pediatric dentistry, particularly for restoring primary tooth structure defects. Materials and methods This study analyzed the effects of three surface treatment modalities on PEEK’s surface morphology, wettability (as measured by contact angle), and shear bond strength. These treatments included alumina (Al2O3) sandblasting alone, and in conjunction with a 98% sulfuric acid pretreatment. Subsequently, an evaluation was conducted to assess the compressive and fatigue properties of self-fabricated PEEK preformed crowns, preformed metal crowns, and preformed zirconia crowns. Results Al2O3 sandblasting followed by sulfuric acid pretreatment significantly enhanced the bond strength of PEEK. PEEK crowns, when compared with stainless steel and zirconia crowns, showed similar compressive and fatigue strengths to zirconia crowns but lower than metal alternatives. Additionally, PEEK crowns required less extensive modification of dental abutments compared to zirconia crowns. Conclusions The study concludes that PEEK prefabricated crown, especially after alumina (Al2O3) sandblasting in conjunction with a 98% sulfuric acid pretreatment, exhibits improved bond strength and favorable material characteristics for use in pediatric dental restorations. Clinical relevance The findings highlight the potential of PEEK prefabricated crowns in pediatric dentistry as a viable option for the aesthetic restoration of primary teeth, offering benefits over traditional materials like stainless steel and zirconia in terms of preferable compressive and fatigue strengths and ideal reduction of dental abutments.