Pub Date : 2022-01-01DOI: 10.3934/matersci.2022010
M. M. A. Filho, P. Piloto, Carlos Balsa
Composite slabs with steel deck combine the load-bearing resistance of the steel deck and rebar with the compressive resistance of the concrete (components). Unprotected composite slabs may be exposed to natural fire conditions from below, and steel reduces its load-bearing capacity during the heating stage. In short fire events, with limited deformations, the composite slabs can recover the load-bearing capacity during the cooling stage. This research presents the validation of the numerical model and the development of a parametric study, to evaluate the load-bearing capacity during the fire event. This method includes a time step procedure, based on the average temperature calculation for each component, including the reduction coefficients applied to the design strength of each material. A new proposal is also presented to evaluate the residual load-bearing capacity. In some circumstances, the residual load-bearing can be reduced by more than 20%. The results showed that the highest variation in the load-bearing resistance of composite slabs occurs when the steel temperatures are between 20 and 600 ℃, after this temperature, the steel has already lost most of its mechanical strength. Moreover, it was observed that different heating rates and different cooling rates influence the rate of the reduction and recovery of the load-bearing capacity. It was also noticed that the lowest load-bearing capacity of the composite slabs was reached after the end of the heating phase, showing that the stability of the element during the heating phase does not guarantee fire safety during the cooling phase.
{"title":"The load-bearing of composite slabs with steel deck under natural fires","authors":"M. M. A. Filho, P. Piloto, Carlos Balsa","doi":"10.3934/matersci.2022010","DOIUrl":"https://doi.org/10.3934/matersci.2022010","url":null,"abstract":"Composite slabs with steel deck combine the load-bearing resistance of the steel deck and rebar with the compressive resistance of the concrete (components). Unprotected composite slabs may be exposed to natural fire conditions from below, and steel reduces its load-bearing capacity during the heating stage. In short fire events, with limited deformations, the composite slabs can recover the load-bearing capacity during the cooling stage. This research presents the validation of the numerical model and the development of a parametric study, to evaluate the load-bearing capacity during the fire event. This method includes a time step procedure, based on the average temperature calculation for each component, including the reduction coefficients applied to the design strength of each material. A new proposal is also presented to evaluate the residual load-bearing capacity. In some circumstances, the residual load-bearing can be reduced by more than 20%. The results showed that the highest variation in the load-bearing resistance of composite slabs occurs when the steel temperatures are between 20 and 600 ℃, after this temperature, the steel has already lost most of its mechanical strength. Moreover, it was observed that different heating rates and different cooling rates influence the rate of the reduction and recovery of the load-bearing capacity. It was also noticed that the lowest load-bearing capacity of the composite slabs was reached after the end of the heating phase, showing that the stability of the element during the heating phase does not guarantee fire safety during the cooling phase.","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70087880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.3934/matersci.2022041
S. Chattopadhyay, U. N
This paper focuses on the investigation of the flexural behaviour of steel-concrete composite beams through non-linear finite element analysis. Both geometries, as well as material non-linearity, are considered. Steel-concrete composite beams are typically made consisting of a hot-rolled I-section steel beam and a concrete slab that is connected monolithically by using a shear connector. A shear connector is one of the key elements for developing the composite action used in steel-concrete composite structures. This paper deals with the flexible shear connectors such as studs and channels designed as per the Indian standards 11384. Initially, the FE models are validated by making comparisons with the experimental test results obtained by previous researchers, as available in the literature. In the present study, thirty three-dimensional simply supported composite beams are created and analysed using finite element commercial software package ANSYS15 workbench version subjected to two-point loads. The degree of shear connection, the strength of steel section and the geometry of stud and channel connectors are the primary parameters considered for the present research work, and the results are compared. The overall flexural response is provided, including failure modes, load-central deformation behaviour, and interface slip, as well as the effects of yield strength of steel, the geometry of the stud and channel shear connector along with the degree of shear interaction, are evaluated. The results show that the degree of interaction, the geometry of shear connectors and steel yield strength have significant influence. Subjected to flexure, steel-concrete composite beam section with channel connector is less evaluated so far; therefore, in the present research work, channel shear connector is taken into account to evaluate the flexural behaviour with the consideration of varying grades of steel section along with the degree of interaction and to compare the results with a different section of shear connectors.
{"title":"Numerical investigation of steel-concrete composite beams using flexible shear connectors","authors":"S. Chattopadhyay, U. N","doi":"10.3934/matersci.2022041","DOIUrl":"https://doi.org/10.3934/matersci.2022041","url":null,"abstract":"This paper focuses on the investigation of the flexural behaviour of steel-concrete composite beams through non-linear finite element analysis. Both geometries, as well as material non-linearity, are considered. Steel-concrete composite beams are typically made consisting of a hot-rolled I-section steel beam and a concrete slab that is connected monolithically by using a shear connector. A shear connector is one of the key elements for developing the composite action used in steel-concrete composite structures. This paper deals with the flexible shear connectors such as studs and channels designed as per the Indian standards 11384. Initially, the FE models are validated by making comparisons with the experimental test results obtained by previous researchers, as available in the literature. In the present study, thirty three-dimensional simply supported composite beams are created and analysed using finite element commercial software package ANSYS15 workbench version subjected to two-point loads. The degree of shear connection, the strength of steel section and the geometry of stud and channel connectors are the primary parameters considered for the present research work, and the results are compared. The overall flexural response is provided, including failure modes, load-central deformation behaviour, and interface slip, as well as the effects of yield strength of steel, the geometry of the stud and channel shear connector along with the degree of shear interaction, are evaluated. The results show that the degree of interaction, the geometry of shear connectors and steel yield strength have significant influence. Subjected to flexure, steel-concrete composite beam section with channel connector is less evaluated so far; therefore, in the present research work, channel shear connector is taken into account to evaluate the flexural behaviour with the consideration of varying grades of steel section along with the degree of interaction and to compare the results with a different section of shear connectors.","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70089282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.3934/matersci.2022053
Ehsan Harati, P. Kah
The trend is shifting from internal combustion engines (ICEs) to battery electric vehicles (BEVs). One of the important battery joints is battery tabs to the busbar connection. Aluminum (Al) and copper (Cu) are among the common materials for busbar and battery tab manufacturing. A wide range of research shows that the laser welding of busbar to battery tabs is a very promising technique. It can enhance the battery module's safety and reliability owing to its unique properties. The desired strength, ductility, fatigue life as well as electrical resistivity are crucial to attain in laser welding of dissimilar materials aluminum and copper in busbar to battery tab in BEVs. Therefore, an adequate understating of the principal factors influencing the Al–Cu busbar to battery tabs joint properties are of prime importance. The current review paper provides information on laser welding and laser brazing of dissimilar Al–Cu with thin thicknesses. Also, the common defects, the effect of materials properties on laser joining, and laser-materials interaction during the laser welding process are discussed. Laser process parameters adjustment (e.g., laser power or speed), laser operational mode, and proper choice of materials (e.g., base metals, alloying elements, filler metals, etc.) may enhance the joint properties in terms of mechanical and electrical properties.
{"title":"Laser welding of aluminum battery tab to variable Al/Cu busbars in Li-ion battery joint","authors":"Ehsan Harati, P. Kah","doi":"10.3934/matersci.2022053","DOIUrl":"https://doi.org/10.3934/matersci.2022053","url":null,"abstract":"The trend is shifting from internal combustion engines (ICEs) to battery electric vehicles (BEVs). One of the important battery joints is battery tabs to the busbar connection. Aluminum (Al) and copper (Cu) are among the common materials for busbar and battery tab manufacturing. A wide range of research shows that the laser welding of busbar to battery tabs is a very promising technique. It can enhance the battery module's safety and reliability owing to its unique properties. The desired strength, ductility, fatigue life as well as electrical resistivity are crucial to attain in laser welding of dissimilar materials aluminum and copper in busbar to battery tab in BEVs. Therefore, an adequate understating of the principal factors influencing the Al–Cu busbar to battery tabs joint properties are of prime importance. The current review paper provides information on laser welding and laser brazing of dissimilar Al–Cu with thin thicknesses. Also, the common defects, the effect of materials properties on laser joining, and laser-materials interaction during the laser welding process are discussed. Laser process parameters adjustment (e.g., laser power or speed), laser operational mode, and proper choice of materials (e.g., base metals, alloying elements, filler metals, etc.) may enhance the joint properties in terms of mechanical and electrical properties.","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70089300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.3934/matersci.2022043
H. Altenbach, O. Larin, K. Naumenko, O. Sukhanova, M. Würkner
The aim of this paper is to compare the classical continuum mechanics and the peridynamic models in the structural analysis of a monolithic glass plate subjected to ball drop. Governing equations are recalled in order to highlight the differences and basic features of both approaches. In this study the behavior of glass is assumed to be linear-elastic and damage processes are ignored. The generalized Hooke's law is assumed within the classical theory, while the linear peridynamic solid constitutive model is applied within the peridynamic analysis. Mechanical models for the ball drop simulation are discussed in detail. An emphasis is placed on the discretization including finite element mesh, peridynamic node lattice and time stepping, as well as appropriate constraints and contact conditions in both finite element and non-local peridynamics models. Deflections of the plate after the ball drop are presented as functions of time and the results based on the finite element and peridynamic analysis are compared. Good agreements between the deflection values in selected points of the plate as well as deflection fields at several time points indicate, that the model assumptions for the non-local peridynamic analysis including the horizon size, the short-range force contact settings and the support conditions are well suited. The developed peridynamics models can be applied in the future to analyze damage patterns in glass plates.
{"title":"Elastic plate under low velocity impact: Classical continuum mechanics vs peridynamics analysis","authors":"H. Altenbach, O. Larin, K. Naumenko, O. Sukhanova, M. Würkner","doi":"10.3934/matersci.2022043","DOIUrl":"https://doi.org/10.3934/matersci.2022043","url":null,"abstract":"The aim of this paper is to compare the classical continuum mechanics and the peridynamic models in the structural analysis of a monolithic glass plate subjected to ball drop. Governing equations are recalled in order to highlight the differences and basic features of both approaches. In this study the behavior of glass is assumed to be linear-elastic and damage processes are ignored. The generalized Hooke's law is assumed within the classical theory, while the linear peridynamic solid constitutive model is applied within the peridynamic analysis. Mechanical models for the ball drop simulation are discussed in detail. An emphasis is placed on the discretization including finite element mesh, peridynamic node lattice and time stepping, as well as appropriate constraints and contact conditions in both finite element and non-local peridynamics models. Deflections of the plate after the ball drop are presented as functions of time and the results based on the finite element and peridynamic analysis are compared. Good agreements between the deflection values in selected points of the plate as well as deflection fields at several time points indicate, that the model assumptions for the non-local peridynamic analysis including the horizon size, the short-range force contact settings and the support conditions are well suited. The developed peridynamics models can be applied in the future to analyze damage patterns in glass plates.","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70089424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.3934/matersci.2022031
A. Abdullah, A. Haider, A. A. Jabbar
In this research, two pellets of titanium dioxide TiO2 were prepared at room temperature. The first was pure titanium dioxide, and the other was doped with silver (2.5%). The pellets were deposited on porous silicon (PSi) with the pulsed laser deposition (PLD) technique. The results of scanning electron microscopy and energy-dispersive X-ray spectroscopy showed improvements in the surface morphologies of the TiO2/PSi and TiO2@Ag/PSi composites. The composites were then tested as CO2 gas sensors. The electrical measurements of the composites showed a decrease in the electrical resistance of the CO2 gas sensor doped with a metal. Sensitivity to CO2 increased to up to 55% in Ag-doped TiO2 film with a concentration of 2.5%, and the highest sensitivity value was obtained in the pure titanium dioxide film (26%).
{"title":"Pure TiO2/PSi and TiO2@Ag/PSi structures as controllable sensor for toxic gases","authors":"A. Abdullah, A. Haider, A. A. Jabbar","doi":"10.3934/matersci.2022031","DOIUrl":"https://doi.org/10.3934/matersci.2022031","url":null,"abstract":"<abstract> <p>In this research, two pellets of titanium dioxide TiO<sub>2</sub> were prepared at room temperature. The first was pure titanium dioxide, and the other was doped with silver (2.5%). The pellets were deposited on porous silicon (PSi) with the pulsed laser deposition (PLD) technique. The results of scanning electron microscopy and energy-dispersive X-ray spectroscopy showed improvements in the surface morphologies of the TiO<sub>2</sub>/PSi and TiO<sub>2</sub>@Ag/PSi composites. The composites were then tested as CO<sub>2</sub> gas sensors. The electrical measurements of the composites showed a decrease in the electrical resistance of the CO<sub>2</sub> gas sensor doped with a metal. Sensitivity to CO<sub>2</sub> increased to up to 55% in Ag-doped TiO<sub>2</sub> film with a concentration of 2.5%, and the highest sensitivity value was obtained in the pure titanium dioxide film (26%).</p> </abstract>","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70088890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.3934/matersci.2022033
E. S. Hadi, O. Kurdi, A. Bs, R. Ismail, M. Tauviqirrahman
Ultrahigh molecular weight polyethene (UHMWPE) is employed as a bearing material in a range of applications due to its improved elasticity, compatibility, and impact resistance, processing conditions for a suitable surface texture are necessary. Surface texture processing on microchannels using lasers is always associated with the effect of heat damage on the polymer specimen surface. This study aims to explore the use of polydimethylsiloxane (PDMS) and polyacrylic acid (PAA) in the form of liquid gel coatings in order to reduce heat damage to surfaces during the laser processing of ultrahigh molecular weight polyethene (UHMWPE). First, PDMS and PAA were coated on the surface of the UHMWPE material specimen, and then texturing was performed using a laser diode and cleaned using the ultrasonic method. Second, the dimensions and texture profiles of all the samples from this study were measured using a confocal microscope and open source software. In addition, the effect of adding liquid gel on the surface at 150 µm thickness and laser power parameters was determined. The results show that the PDMS and PAA liquid gel layers help regulate the dimensional bulge of the fabricated microchannels at laser powers below 6 watts, compared to those produced without the coating.
{"title":"Influence of laser processing conditions for the manufacture of microchannels on ultrahigh molecular weight polyethylene coated with PDMS and PAA","authors":"E. S. Hadi, O. Kurdi, A. Bs, R. Ismail, M. Tauviqirrahman","doi":"10.3934/matersci.2022033","DOIUrl":"https://doi.org/10.3934/matersci.2022033","url":null,"abstract":"Ultrahigh molecular weight polyethene (UHMWPE) is employed as a bearing material in a range of applications due to its improved elasticity, compatibility, and impact resistance, processing conditions for a suitable surface texture are necessary. Surface texture processing on microchannels using lasers is always associated with the effect of heat damage on the polymer specimen surface. This study aims to explore the use of polydimethylsiloxane (PDMS) and polyacrylic acid (PAA) in the form of liquid gel coatings in order to reduce heat damage to surfaces during the laser processing of ultrahigh molecular weight polyethene (UHMWPE). First, PDMS and PAA were coated on the surface of the UHMWPE material specimen, and then texturing was performed using a laser diode and cleaned using the ultrasonic method. Second, the dimensions and texture profiles of all the samples from this study were measured using a confocal microscope and open source software. In addition, the effect of adding liquid gel on the surface at 150 µm thickness and laser power parameters was determined. The results show that the PDMS and PAA liquid gel layers help regulate the dimensional bulge of the fabricated microchannels at laser powers below 6 watts, compared to those produced without the coating.","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70088982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.3934/matersci.2022037
N. E. Safie, M. Azam
The production of pristine graphene materials for industrialization, often limited by the complicated synthesis route, has introduced other graphene derivatives with a workable and facile synthesis route, especially for mass production. For the chemical exfoliation process, the synthesis involves oxidants and reducing agents to exfoliate the graphene layer from the 3D graphite and remove excess oxygen-containing functional groups yielding graphene-like materials known as reduced graphene oxide (rGO). This work feasibly produces rGO with nanoplatelet morphology through the green solution-processable method. Upon reduction, the crystallite size for the a-axis (La) is more prominent (22.50 Å) than the crystallite size for the c-axis (Lc) (11.50 Å), suggesting the nanoplatelets structure of the end product, which is also confirmed by the morphology. The integrated intensity (ID/IG) ratio and average defect density (nD) of as-prepared rGO confirmed the sp2 restoration in the graphitic structure. Overall, the Raman and X-ray diffraction (XRD) characterization parameters validate the production of rGO nanoplatelets, especially with four graphene layers per domain, suggesting that high-quality rGO are achievable and ready to be implemented for the large-scale production.
{"title":"Understanding the structural properties of feasible chemically reduced graphene","authors":"N. E. Safie, M. Azam","doi":"10.3934/matersci.2022037","DOIUrl":"https://doi.org/10.3934/matersci.2022037","url":null,"abstract":"<abstract> <p>The production of pristine graphene materials for industrialization, often limited by the complicated synthesis route, has introduced other graphene derivatives with a workable and facile synthesis route, especially for mass production. For the chemical exfoliation process, the synthesis involves oxidants and reducing agents to exfoliate the graphene layer from the 3D graphite and remove excess oxygen-containing functional groups yielding graphene-like materials known as reduced graphene oxide (rGO). This work feasibly produces rGO with nanoplatelet morphology through the green solution-processable method. Upon reduction, the crystallite size for the a-axis (<italic>L<sub>a</sub></italic>) is more prominent (22.50 Å) than the crystallite size for the c-axis (<italic>L<sub>c</sub></italic>) (11.50 Å), suggesting the nanoplatelets structure of the end product, which is also confirmed by the morphology. The integrated intensity (<italic>I</italic><sub>D</sub>/<italic>I</italic><sub>G</sub>) ratio and average defect density (<italic>n<sub>D</sub></italic>) of as-prepared rGO confirmed the sp<sup>2</sup> restoration in the graphitic structure. Overall, the Raman and X-ray diffraction (XRD) characterization parameters validate the production of rGO nanoplatelets, especially with four graphene layers per domain, suggesting that high-quality rGO are achievable and ready to be implemented for the large-scale production.</p> </abstract>","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70089089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.3934/matersci.2022042
K. A. Lazopoulos, E. Sideridis, A. Lazopoulos
Λ-Fractional Mechanics has already been introduced since it combines non-locality with mathematical analysis. It is well established, that conventional mechanics is not a proper theory for describing various phenomena in micro or nanomechanics. Further, various experiments in viscoelasticity, fatigue, fracture, etc., suggest the introduction of non-local mathematical analysis in their description. Fractional calculus has been used in describing those phenomena. Nevertheless, the well-known fractional derivatives with their calculus fail to generate differential geometry, since the established fractional derivatives do not fulfill the prerequisites of differential topology. A Λ-fractional analysis can generate geometry conforming to the prerequisites of differential topology. Hence Λ-fractional mechanics deals with non-local mechanics, describing the various inhomogeneities in various materials with more realistic rules.
{"title":"On Λ-Fractional peridynamic mechanics","authors":"K. A. Lazopoulos, E. Sideridis, A. Lazopoulos","doi":"10.3934/matersci.2022042","DOIUrl":"https://doi.org/10.3934/matersci.2022042","url":null,"abstract":"Λ-Fractional Mechanics has already been introduced since it combines non-locality with mathematical analysis. It is well established, that conventional mechanics is not a proper theory for describing various phenomena in micro or nanomechanics. Further, various experiments in viscoelasticity, fatigue, fracture, etc., suggest the introduction of non-local mathematical analysis in their description. Fractional calculus has been used in describing those phenomena. Nevertheless, the well-known fractional derivatives with their calculus fail to generate differential geometry, since the established fractional derivatives do not fulfill the prerequisites of differential topology. A Λ-fractional analysis can generate geometry conforming to the prerequisites of differential topology. Hence Λ-fractional mechanics deals with non-local mechanics, describing the various inhomogeneities in various materials with more realistic rules.","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70089342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.3934/matersci.2022008
Nurhusien Hassen Mohammed, Desalegn Wogaso Wolla
Machining natural fiber reinforced polymer composite materials is one of most challenging tasks due to the material's anisotropic property, non-homogeneous structure and abrasive nature of fibers. Commonly, conventional machining of composites leads to delamination, inter-laminar cracks, fiber pull out, poor surface finish and wear of cutting tool. However, these challenges can be significantly reduced by using proper machining conditions. Thus, this research aims at optimizing machining parameters in drilling hybrid sisal-cotton fibers reinforced polyester composite for better machining performance characteristics namely better hole roundness accuracy and surface finish using Taguchi method. The effect of machining parameters including spindle speed, feed rate and drill diameter on drill hole accuracy (roundness error) and surface-roughness of the hybrid composite are evaluated. Series of experiments based on Taguchi's L16 orthogonal array were performed using different ranges of machining parameters namely spindle speed (600,900, 1200, 1600 rpm), feed rate (10, 15, 20, 25 mm/min) and drill diameter (6, 7, 8, 10 mm). Hole roundness error and surface-roughness are determined using ABC digital caliper and Zeta 20 profilometer, respectively. Optimum machining condition for drilling hybrid composite material (speed: 1600 rpm, feed rate: 25 mm/min and drill diameter: 6 mm) is determined, and the results are verified by conducting confirmation test which proves that the results are reliable.
{"title":"Optimization of machining parameters in drilling hybrid sisal-cotton fiber reinforced polyester composites","authors":"Nurhusien Hassen Mohammed, Desalegn Wogaso Wolla","doi":"10.3934/matersci.2022008","DOIUrl":"https://doi.org/10.3934/matersci.2022008","url":null,"abstract":"Machining natural fiber reinforced polymer composite materials is one of most challenging tasks due to the material's anisotropic property, non-homogeneous structure and abrasive nature of fibers. Commonly, conventional machining of composites leads to delamination, inter-laminar cracks, fiber pull out, poor surface finish and wear of cutting tool. However, these challenges can be significantly reduced by using proper machining conditions. Thus, this research aims at optimizing machining parameters in drilling hybrid sisal-cotton fibers reinforced polyester composite for better machining performance characteristics namely better hole roundness accuracy and surface finish using Taguchi method. The effect of machining parameters including spindle speed, feed rate and drill diameter on drill hole accuracy (roundness error) and surface-roughness of the hybrid composite are evaluated. Series of experiments based on Taguchi's L16 orthogonal array were performed using different ranges of machining parameters namely spindle speed (600,900, 1200, 1600 rpm), feed rate (10, 15, 20, 25 mm/min) and drill diameter (6, 7, 8, 10 mm). Hole roundness error and surface-roughness are determined using ABC digital caliper and Zeta 20 profilometer, respectively. Optimum machining condition for drilling hybrid composite material (speed: 1600 rpm, feed rate: 25 mm/min and drill diameter: 6 mm) is determined, and the results are verified by conducting confirmation test which proves that the results are reliable.","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70087817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.3934/matersci.2022011
F. Figueiredo, Pâmela Lopes Pedro da Silva, E. Botero, L. Maia
The expansion of cities contributed to the problems related to the accumulation of waste and lack of control over its management, there are still around 2400 dumps or uncontrolled landfills in Brazil. There is a large volume of polyethylene terephthalate (PET) improperly discarded. In turn, the construction industry has been looking for sustainable ways to produce concrete. This work deals with the analysis of the replacement of PET as a fine aggregate in concrete in the proportions of 5% and 15%. PET particles pass more than 75% in the 2.36 mm opening sieve and have more than 99% of their particle size retained in the 0.15 mm opening sieve. Concrete properties, compressive strength, tensile strength, water absorption and void ratio were evaluated and compared with the reference mix. In total, 45 specimens cast in concrete were used to complete the experiment. The results obtained showed that mixture compositions that incorporate PET as fine aggregates decrease compressive and tensile strength, increase water absorption and void index. The results obtained showed that blending compositions that incorporate PET as fine aggregates decrease compressive strength in about 14%, decrease tensile strength in about 7–11%, increased the void ratio in almost 20% and increased the water absorption in about 30%.
{"title":"Concrete with partial replacement of natural aggregate by PET aggregate—An exploratory study about the influence in the compressive strength","authors":"F. Figueiredo, Pâmela Lopes Pedro da Silva, E. Botero, L. Maia","doi":"10.3934/matersci.2022011","DOIUrl":"https://doi.org/10.3934/matersci.2022011","url":null,"abstract":"The expansion of cities contributed to the problems related to the accumulation of waste and lack of control over its management, there are still around 2400 dumps or uncontrolled landfills in Brazil. There is a large volume of polyethylene terephthalate (PET) improperly discarded. In turn, the construction industry has been looking for sustainable ways to produce concrete. This work deals with the analysis of the replacement of PET as a fine aggregate in concrete in the proportions of 5% and 15%. PET particles pass more than 75% in the 2.36 mm opening sieve and have more than 99% of their particle size retained in the 0.15 mm opening sieve. Concrete properties, compressive strength, tensile strength, water absorption and void ratio were evaluated and compared with the reference mix. In total, 45 specimens cast in concrete were used to complete the experiment. The results obtained showed that mixture compositions that incorporate PET as fine aggregates decrease compressive and tensile strength, increase water absorption and void index. The results obtained showed that blending compositions that incorporate PET as fine aggregates decrease compressive strength in about 14%, decrease tensile strength in about 7–11%, increased the void ratio in almost 20% and increased the water absorption in about 30%.","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70087934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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