Pub Date : 2019-06-13DOI: 10.1142/S1756973718500063
J. Rose, G. Vairamani
This paper investigates the friction and wear behavior of Al-7075 and Basalt fiber metal matrix composite for clutch facing applications by replacing the existing asbestos with Basalt fiber combination. Experiments are done to evaluate the friction and wear properties of Al-7075 and Basalt fiber metal matrix composite material under different sliding velocities and contact loads. The reinforcement percentage of Basalt fiber is varied from 0% to 10% in steps of 2.5% on the weight basis. At present, the clutch facing for the Multi Utility Vehicles (MUV) is made of asbestos as a primary content and its hazardous characteristics are taken into consideration. Initially, the clutch facing specifications of a MUV are observed through field studies and then, design calculations are performed to prepare the structural analysis using ANSYS workbench. The stress–strain characteristics of Al-7075 and Basalt fiber mixture are studied through the computational analysis before the fabrication process. Then, the specimen is fabricated by stir casting technique for the experimental investigation of friction and wear properties using pin-on-disk apparatus. The outcome of the analysis has revealed the use of Al-7075 and Basalt fiber metal matrix composite material as a replacement for the existing clutch facing applications and the results are presented with validations.
{"title":"Experimental Investigation of Friction and Wear Properties of a Clutch Facing Made of Al-7075 with Basalt Fiber Metal Matrix Composite","authors":"J. Rose, G. Vairamani","doi":"10.1142/S1756973718500063","DOIUrl":"https://doi.org/10.1142/S1756973718500063","url":null,"abstract":"This paper investigates the friction and wear behavior of Al-7075 and Basalt fiber metal matrix composite for clutch facing applications by replacing the existing asbestos with Basalt fiber combination. Experiments are done to evaluate the friction and wear properties of Al-7075 and Basalt fiber metal matrix composite material under different sliding velocities and contact loads. The reinforcement percentage of Basalt fiber is varied from 0% to 10% in steps of 2.5% on the weight basis. At present, the clutch facing for the Multi Utility Vehicles (MUV) is made of asbestos as a primary content and its hazardous characteristics are taken into consideration. Initially, the clutch facing specifications of a MUV are observed through field studies and then, design calculations are performed to prepare the structural analysis using ANSYS workbench. The stress–strain characteristics of Al-7075 and Basalt fiber mixture are studied through the computational analysis before the fabrication process. Then, the specimen is fabricated by stir casting technique for the experimental investigation of friction and wear properties using pin-on-disk apparatus. The outcome of the analysis has revealed the use of Al-7075 and Basalt fiber metal matrix composite material as a replacement for the existing clutch facing applications and the results are presented with validations.","PeriodicalId":43242,"journal":{"name":"Journal of Multiscale Modelling","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2019-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1142/S1756973718500063","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41559677","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 : 2019-06-13DOI: 10.1142/S1756973718500099
Ophir Nave, Yifat Baron, Manju Sharma
In this paper, we applied the well-known homotopy analysis methods (HAM), which is a semi-analytical method, perturbation method, to study a reaction–diffusion–advection model for the dynamics of populations under biological control. According to the predator–prey model, the advection expression represents the predator density movement in which the acceleration is proportional to the prey density gradient. The prey population reproduces logistically, and the interactions of prey population obey the Holling’s prey-dependent Type II functional response. The predation process splits into the following subdivided processes: random movement which is represented by diffusion, direct movement which is described by prey taxis, local prey interactions, and consumptions which are represented by the trophic function. In order to ensure a successful biological control, one should make the predator-pest population to stabilize at a very low level of pest density. One reason for this effect is the intermediate taxis activity. However, when the system loses stability, for example very intensive prey taxis destroys the stability, it leads to chaotic dynamics with pronounced outbreaks of pest density.
{"title":"A Semi-Analytical Method for Solving Problems on the Role of Prey Taxis in a Biological Control-Mathematical Model","authors":"Ophir Nave, Yifat Baron, Manju Sharma","doi":"10.1142/S1756973718500099","DOIUrl":"https://doi.org/10.1142/S1756973718500099","url":null,"abstract":"In this paper, we applied the well-known homotopy analysis methods (HAM), which is a semi-analytical method, perturbation method, to study a reaction–diffusion–advection model for the dynamics of populations under biological control. According to the predator–prey model, the advection expression represents the predator density movement in which the acceleration is proportional to the prey density gradient. The prey population reproduces logistically, and the interactions of prey population obey the Holling’s prey-dependent Type II functional response. The predation process splits into the following subdivided processes: random movement which is represented by diffusion, direct movement which is described by prey taxis, local prey interactions, and consumptions which are represented by the trophic function. In order to ensure a successful biological control, one should make the predator-pest population to stabilize at a very low level of pest density. One reason for this effect is the intermediate taxis activity. However, when the system loses stability, for example very intensive prey taxis destroys the stability, it leads to chaotic dynamics with pronounced outbreaks of pest density.","PeriodicalId":43242,"journal":{"name":"Journal of Multiscale Modelling","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2019-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1142/S1756973718500099","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43031756","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 : 2019-06-13DOI: 10.1142/S1756973718500075
A. Selmi
Based on Mindlin’s 2nd gradient model that involves two length-scale parameters, Green’s function, Eshelby tensor and Eshelby-like tensor for an inclusion of arbitrary shape are derived. It is proved that the Eshelby tensor consists of two parts: the classical Eshelby tensor and a gradient part including the length-scale parameters, which enable the interpretation of the size effect. When the strain gradient is not taken into account, the obtained Green’s function and Eshelby tensor reduce to its analogue based on the classical elasticity. For the cylindrical inclusion case, the Eshelby tensor in and outside the inclusion, the volume average of the gradient part and the Eshelby-like tensor are explicitly obtained. Unlike the classical Eshelby tensor, the results show that the components of the new Eshelby tensor vary with the position and the inclusion dimensions. It is demonstrated that the contribution of the gradient part should not be neglected.
{"title":"Green’s Function and Eshelby’s Tensor Based on Mindlin’s 2nd Gradient Model: An Explicit Study of Cylindrical Inclusion Case","authors":"A. Selmi","doi":"10.1142/S1756973718500075","DOIUrl":"https://doi.org/10.1142/S1756973718500075","url":null,"abstract":"Based on Mindlin’s 2nd gradient model that involves two length-scale parameters, Green’s function, Eshelby tensor and Eshelby-like tensor for an inclusion of arbitrary shape are derived. It is proved that the Eshelby tensor consists of two parts: the classical Eshelby tensor and a gradient part including the length-scale parameters, which enable the interpretation of the size effect. When the strain gradient is not taken into account, the obtained Green’s function and Eshelby tensor reduce to its analogue based on the classical elasticity. For the cylindrical inclusion case, the Eshelby tensor in and outside the inclusion, the volume average of the gradient part and the Eshelby-like tensor are explicitly obtained. Unlike the classical Eshelby tensor, the results show that the components of the new Eshelby tensor vary with the position and the inclusion dimensions. It is demonstrated that the contribution of the gradient part should not be neglected.","PeriodicalId":43242,"journal":{"name":"Journal of Multiscale Modelling","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2019-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1142/S1756973718500075","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44463904","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 : 2019-05-08DOI: 10.1142/S1756973718410044
Yang Lu, Linbing Wang
The interface bonding strength is critical for asphalt concrete performance under external load applications. A thorough understanding of the load transfer mechanism bridging the nanoscale interfacial details and the macroscale properties is required to accurately predict the performance of asphalt concrete. This research presents a multiscale analysis procedure for the modeling of interface behaviors, in which material properties are evaluated by atomic scale interactions, emphasizing the complex shearing and separation mechanisms under various loading modes. The representative model system was established based on multiscale experimental characterization of the tight-bonding interface between asphalt and aggregate. Interfacial load transfer and failure studies were conducted for investigating the effect of tension and compression on shearing mode separation. The cohesive zone model parameters, such as peak traction and energy of separation were evaluated for each loading mode. Different boundary conditions were applied to obtain the representative volume element (RVE) and connection to continuum level properties. Results indicated that depending on the various loading modes, the failure of the nanoscale interface system may occur within the asphalt phase or at the interface. These results set the basis for continuum length-scale micromechanical models which may be used to determine the bulk material response, incorporating interfacial phenomena. The findings presented in this paper are consistent with observations reported in previous studies and expand on the understanding of the relationship between molecular structures and combined shearing separation failure properties of asphalt concrete interfaces.
{"title":"Nanomechanics Modeling of Interface Interactions in Asphalt Concrete: Traction and Shearing Failure Study","authors":"Yang Lu, Linbing Wang","doi":"10.1142/S1756973718410044","DOIUrl":"https://doi.org/10.1142/S1756973718410044","url":null,"abstract":"The interface bonding strength is critical for asphalt concrete performance under external load applications. A thorough understanding of the load transfer mechanism bridging the nanoscale interfacial details and the macroscale properties is required to accurately predict the performance of asphalt concrete. This research presents a multiscale analysis procedure for the modeling of interface behaviors, in which material properties are evaluated by atomic scale interactions, emphasizing the complex shearing and separation mechanisms under various loading modes. The representative model system was established based on multiscale experimental characterization of the tight-bonding interface between asphalt and aggregate. Interfacial load transfer and failure studies were conducted for investigating the effect of tension and compression on shearing mode separation. The cohesive zone model parameters, such as peak traction and energy of separation were evaluated for each loading mode. Different boundary conditions were applied to obtain the representative volume element (RVE) and connection to continuum level properties. Results indicated that depending on the various loading modes, the failure of the nanoscale interface system may occur within the asphalt phase or at the interface. These results set the basis for continuum length-scale micromechanical models which may be used to determine the bulk material response, incorporating interfacial phenomena. The findings presented in this paper are consistent with observations reported in previous studies and expand on the understanding of the relationship between molecular structures and combined shearing separation failure properties of asphalt concrete interfaces.","PeriodicalId":43242,"journal":{"name":"Journal of Multiscale Modelling","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2019-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1142/S1756973718410044","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44572987","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 : 2019-05-08DOI: 10.1142/S1756973718410032
Mir Ali Ghaffari, Y. Gong, S. Attarian, S. Xiao
There is a boundary effect due to incomplete horizons of boundary or near-boundary points in peridynamics. In this paper, we propose to attach “fictitious walls” to boundary surfaces so that the boundary effect can be reduced or eliminated. Differing from the concept of “fictitious material layers”, which is only attached to displacement boundary surfaces, “fictitious walls” are attached to both displacement and force boundary surfaces. Three types of fictitious walls are considered in this paper: undeformed, deformed, and periodic. It is recommended to attach “undeformed fictitious walls” to displacement boundaries and “deformed fictitious walls” to force boundaries. “Periodic fictitious walls” are suggested for use in peristatics only. In addition, peridynamics with corrected boundary conditions is then implemented in a hierarchical multiscale method to study rolling contact fatigue. In this hierarchical multiscale framework, the coefficient of friction is passed from molecular dynamics simulations to peridynamics, which models crack initiation and propagation in rolling contact simulations.
{"title":"Peridynamics with Corrected Boundary Conditions and Its Implementation in Multiscale Modeling of Rolling Contact Fatigue","authors":"Mir Ali Ghaffari, Y. Gong, S. Attarian, S. Xiao","doi":"10.1142/S1756973718410032","DOIUrl":"https://doi.org/10.1142/S1756973718410032","url":null,"abstract":"There is a boundary effect due to incomplete horizons of boundary or near-boundary points in peridynamics. In this paper, we propose to attach “fictitious walls” to boundary surfaces so that the boundary effect can be reduced or eliminated. Differing from the concept of “fictitious material layers”, which is only attached to displacement boundary surfaces, “fictitious walls” are attached to both displacement and force boundary surfaces. Three types of fictitious walls are considered in this paper: undeformed, deformed, and periodic. It is recommended to attach “undeformed fictitious walls” to displacement boundaries and “deformed fictitious walls” to force boundaries. “Periodic fictitious walls” are suggested for use in peristatics only. In addition, peridynamics with corrected boundary conditions is then implemented in a hierarchical multiscale method to study rolling contact fatigue. In this hierarchical multiscale framework, the coefficient of friction is passed from molecular dynamics simulations to peridynamics, which models crack initiation and propagation in rolling contact simulations.","PeriodicalId":43242,"journal":{"name":"Journal of Multiscale Modelling","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2019-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1142/S1756973718410032","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47149570","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 : 2019-05-08DOI: 10.1142/S1756973718410056
L. Rodríguez-Tembleque, F. García-Sánchez, A. Sáez
A robust boundary element numerical scheme is presented to study crack-face frictional contact in cracked fiber reinforced composite materials. The dual boundary element method is considered for modeling fracture mechanics on these materials. The formulation is based on contact operators over the augmented Lagrangian to enforce contact constraints on the crack surface. Moreover, it considers a Halpin–Tsai macro model for fiber reinforced composite materials which makes it possible to take into account the influence of micromechanical aspects such as: the fibers’ orientation, the fiber’s aspect ratio or the fiber’s volume fraction, estimating the mechanical properties of these composite materials from the known values of the fiber and the matrix. After solving a crack face frictional contact benchmark problem, the capabilities of this methodology are illustrated by studying the influence of not only these micromechanical aspects but also crack face frictional contact conditions on a fractured carbon fiber-reinforced polymer under compression.
{"title":"Crack Surface Frictional Contact Modeling in Fractured Fiber-Reinforced Composites","authors":"L. Rodríguez-Tembleque, F. García-Sánchez, A. Sáez","doi":"10.1142/S1756973718410056","DOIUrl":"https://doi.org/10.1142/S1756973718410056","url":null,"abstract":"A robust boundary element numerical scheme is presented to study crack-face frictional contact in cracked fiber reinforced composite materials. The dual boundary element method is considered for modeling fracture mechanics on these materials. The formulation is based on contact operators over the augmented Lagrangian to enforce contact constraints on the crack surface. Moreover, it considers a Halpin–Tsai macro model for fiber reinforced composite materials which makes it possible to take into account the influence of micromechanical aspects such as: the fibers’ orientation, the fiber’s aspect ratio or the fiber’s volume fraction, estimating the mechanical properties of these composite materials from the known values of the fiber and the matrix. After solving a crack face frictional contact benchmark problem, the capabilities of this methodology are illustrated by studying the influence of not only these micromechanical aspects but also crack face frictional contact conditions on a fractured carbon fiber-reinforced polymer under compression.","PeriodicalId":43242,"journal":{"name":"Journal of Multiscale Modelling","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2019-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1142/S1756973718410056","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44256356","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 : 2019-03-01DOI: 10.1142/S1756973718410019
Asghar Ali Maitlo, F. Lebon, C. Bauzet
The aim of this paper is to propose a model of bonded interface including nonlocal damage and unilateral conditions. The model is derived from the problem of a composite structure made by two adherents and a thin adhesive. The adhesive is damaged at microscopic level and is subjected to two regimes, one in traction and one in compression. The model of interface is derived by matched asymptotic expansions. In this paper, two cases corresponding to the two regimes are discussed. Moreover, this model can be considered as a model of contact with adhesion and unilateral constraint. At the end of the paper, a simple numerical example is presented to show the evolution of the model.
{"title":"A Multi-Scale Model of Soft Imperfect Interface with Nonlocal Damage","authors":"Asghar Ali Maitlo, F. Lebon, C. Bauzet","doi":"10.1142/S1756973718410019","DOIUrl":"https://doi.org/10.1142/S1756973718410019","url":null,"abstract":"The aim of this paper is to propose a model of bonded interface including nonlocal damage and unilateral conditions. The model is derived from the problem of a composite structure made by two adherents and a thin adhesive. The adhesive is damaged at microscopic level and is subjected to two regimes, one in traction and one in compression. The model of interface is derived by matched asymptotic expansions. In this paper, two cases corresponding to the two regimes are discussed. Moreover, this model can be considered as a model of contact with adhesion and unilateral constraint. At the end of the paper, a simple numerical example is presented to show the evolution of the model.","PeriodicalId":43242,"journal":{"name":"Journal of Multiscale Modelling","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1142/S1756973718410019","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47212365","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 : 2018-12-01DOI: 10.1142/S1756973718500051
A. El Baroudi, F. Razafimahery
In the current study, a theoretical method is developed to predict the vibrational behavior of micro-circular disks filled with viscous fluids and numerical results are presented to validate the model. Vibrations with two outer boundary conditions, rigid and deformable vessel, are studied. The coupled governing equations of both rigid and deformable vessel vibration are solved by the analytical procedure, taking fluid–structure interaction into account. The fluid gap effect on the coupled eigenfrequencies is also considered. The frequency spectrum plots of the first several eigenfrequencies are presented in a wide range of fluid gap and elasticity ratio. The correctness of results is demonstrated using a commercial finite element software. It is shown that the obtained results through the proposed method reveal very good agreement with the numerical solution.
{"title":"Prediction of Vibration Behavior of Micro-Circular Disks at Low Reynolds Number Regime","authors":"A. El Baroudi, F. Razafimahery","doi":"10.1142/S1756973718500051","DOIUrl":"https://doi.org/10.1142/S1756973718500051","url":null,"abstract":"In the current study, a theoretical method is developed to predict the vibrational behavior of micro-circular disks filled with viscous fluids and numerical results are presented to validate the model. Vibrations with two outer boundary conditions, rigid and deformable vessel, are studied. The coupled governing equations of both rigid and deformable vessel vibration are solved by the analytical procedure, taking fluid–structure interaction into account. The fluid gap effect on the coupled eigenfrequencies is also considered. The frequency spectrum plots of the first several eigenfrequencies are presented in a wide range of fluid gap and elasticity ratio. The correctness of results is demonstrated using a commercial finite element software. It is shown that the obtained results through the proposed method reveal very good agreement with the numerical solution.","PeriodicalId":43242,"journal":{"name":"Journal of Multiscale Modelling","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1142/S1756973718500051","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44685418","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 : 2018-12-01DOI: 10.1142/S1756973718500087
Ophir Nave
In this paper, we apply a new algorithm called method of directly defining the inverse mapping (MDDiM) that was introduced by Liao for finding a semi-analytical solution to nonlinear system of differential equations. We apply this new method to the autoignition of a monodisperse fuel spray model. We use this technique for finding the base functions in the considered algorithm. Our results include a comparison between a numerical simulation and an analytical solutions derived from the MDDiM.
{"title":"A New Method to Find the Base Functions for the Method of Directly Defining the Inverse Mapping (MDDiM)","authors":"Ophir Nave","doi":"10.1142/S1756973718500087","DOIUrl":"https://doi.org/10.1142/S1756973718500087","url":null,"abstract":"In this paper, we apply a new algorithm called method of directly defining the inverse mapping (MDDiM) that was introduced by Liao for finding a semi-analytical solution to nonlinear system of differential equations. We apply this new method to the autoignition of a monodisperse fuel spray model. We use this technique for finding the base functions in the considered algorithm. Our results include a comparison between a numerical simulation and an analytical solutions derived from the MDDiM.","PeriodicalId":43242,"journal":{"name":"Journal of Multiscale Modelling","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1142/S1756973718500087","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43190894","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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