Pub Date : 2022-09-24DOI: 10.13052/ejcm2642-2085.3131
G. Vincze, A. Lopes, M. Butuc, Jesús M. V. Yánez, D. Lopes, Laura Holz, Ana Graça, A. Pereira
One of the most important characteristics of the sheet metal is its anisotropy. Asymmetric rolling (ASR) shows to be an adequate process to change the material anisotropy by increasing the normal anisotropy and decreasing the planar anisotropy. In this work, it is analysed the relationship between anisotropy and texture evolution using experimental and numerical approaches. Experimentally, the texture is modified by rolling, involving symmetric (SR), asymmetric rolling continuous (ARC) and asymmetric reverse (ARR) routes and different reductions per pass. The numerical analysis was performed through the visco-plastic self-consistent model where two hardening laws were considered, namely the Voce-type (V) and the dislocation density-based model (DDR). The main objective of the numerical method was to test the performance of the VPSC model for large plastic deformation. The Lankford coefficients decrease in RD and increase in TD with the increase in the total thickness reduction. This trend observed experimentally is well captured by the VPSC model, however, in terms of R-value, an overestimation is observed in both cases with better results for Voce-type law.
{"title":"Numerical and Experimental Analysis of the Anisotropy Evolution in Aluminium Alloys Processed by Asymmetric Rolling","authors":"G. Vincze, A. Lopes, M. Butuc, Jesús M. V. Yánez, D. Lopes, Laura Holz, Ana Graça, A. Pereira","doi":"10.13052/ejcm2642-2085.3131","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3131","url":null,"abstract":"\u0000One of the most important characteristics of the sheet metal is its anisotropy. Asymmetric rolling (ASR) shows to be an adequate process to change the material anisotropy by increasing the normal anisotropy and decreasing the planar anisotropy. In this work, it is analysed the relationship between anisotropy and texture evolution using experimental and numerical approaches. Experimentally, the texture is modified by rolling, involving symmetric (SR), asymmetric rolling continuous (ARC) and asymmetric reverse (ARR) routes and different reductions per pass. The numerical analysis was performed through the visco-plastic self-consistent model where two hardening laws were considered, namely the Voce-type (V) and the dislocation density-based model (DDR). The main objective of the numerical method was to test the performance of the VPSC model for large plastic deformation. The Lankford coefficients decrease in RD and increase in TD with the increase in the total thickness reduction. This trend observed experimentally is well captured by the VPSC model, however, in terms of R-value, an overestimation is observed in both cases with better results for Voce-type law.\u0000","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42526685","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 : 2022-08-20DOI: 10.13052/ejcm2642-2085.3124
H. Sharifi
The problem of thermoelastic stress wave propagation in an orthotropic hollow cylinder is investigated using analytical methods. The fully coupled classical theory of thermoelasticity is used to extract the equations for an orthotropic cylinder. To solve the boundary value problem, heat conduction equation and equation of motion are divided into two different sets of equations, the first set consists of uncoupled equations with considering boundary conditions and the second set comprises coupled ones with initial conditions. Finite Hankel transform (Fourier-Bessel expansion) is utilized to solve the problem with respect to radial variable. Two different cases, pure mechanical load and pure thermal load, were studied numerically to show the effect of considering the thermomechanical coupling term in the heat conduction equation. To show the effect of considering the coupling term in the heat conduction equation, the temperature history is plotted for the pure mechanical load case, where the temperature rises without applying any thermal load. By applying boundary conditions on the inner surface of the cylinder, initiation of the stress waves from the inner surface of the cylinder, propagation through the thickness in the radial direction and reflection from the outer surface were observed in the plotted figures.
{"title":"Analytical Solution for Thermoelastic Stress Wave Propagation in an Orthotropic Hollow Cylinder","authors":"H. Sharifi","doi":"10.13052/ejcm2642-2085.3124","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3124","url":null,"abstract":"The problem of thermoelastic stress wave propagation in an orthotropic hollow cylinder is investigated using analytical methods. The fully coupled classical theory of thermoelasticity is used to extract the equations for an orthotropic cylinder. To solve the boundary value problem, heat conduction equation and equation of motion are divided into two different sets of equations, the first set consists of uncoupled equations with considering boundary conditions and the second set comprises coupled ones with initial conditions. Finite Hankel transform (Fourier-Bessel expansion) is utilized to solve the problem with respect to radial variable. Two different cases, pure mechanical load and pure thermal load, were studied numerically to show the effect of considering the thermomechanical coupling term in the heat conduction equation. To show the effect of considering the coupling term in the heat conduction equation, the temperature history is plotted for the pure mechanical load case, where the temperature rises without applying any thermal load. By applying boundary conditions on the inner surface of the cylinder, initiation of the stress waves from the inner surface of the cylinder, propagation through the thickness in the radial direction and reflection from the outer surface were observed in the plotted figures.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46488912","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 : 2022-08-20DOI: 10.13052/ejcm2642-2085.3125
H. Rahmani, M. Elhami, Amin Moslemi Petrudi
In this research, while investigating the vibration analysis of rotary axes, we specifically investigate the rotor of a turbofan engine used in the industry. The features of this rotor range are high-performance, lightweight, and low-vibration range. These three factors are in contradiction with each other, resulting in a thorough examination of the total vibration of the complete turbofan rotor. To achieve this, various parameters such as the concentration of properties, rotational inertia, gyroscopic torque, rotational loading, effects of unbalanced mass, crevillous effects, bearing flexibility, etc. have been studied in modeling. The rotor’s natural frequencies, along with the critical velocity, are plotted as well as the shape of its modes. The software is required to perform the computations written by Ansys software and after ensuring its accuracy.
{"title":"Dynamics and Vibration Analysis of a Rotor-Bearing System in a Turbofan Engine with Emphasis on Bearings Modeling","authors":"H. Rahmani, M. Elhami, Amin Moslemi Petrudi","doi":"10.13052/ejcm2642-2085.3125","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3125","url":null,"abstract":"In this research, while investigating the vibration analysis of rotary axes, we specifically investigate the rotor of a turbofan engine used in the industry. The features of this rotor range are high-performance, lightweight, and low-vibration range. These three factors are in contradiction with each other, resulting in a thorough examination of the total vibration of the complete turbofan rotor. To achieve this, various parameters such as the concentration of properties, rotational inertia, gyroscopic torque, rotational loading, effects of unbalanced mass, crevillous effects, bearing flexibility, etc. have been studied in modeling. The rotor’s natural frequencies, along with the critical velocity, are plotted as well as the shape of its modes. The software is required to perform the computations written by Ansys software and after ensuring its accuracy.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44912895","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 : 2022-08-13DOI: 10.13052/ejcm2642-2085.3122
Xue Xiao, Zheng Yangbing, Wang Xin
In this paper, a prediction method of characteristic value of foundation bearing capacity based on machine learning algorithm is proposed. Firstly, the influencing factors of foundation bearing capacity are analyzed, and then the prediction parameters of foundation pressure strength and foundation strength are calculated. The prediction error was obtained by comparing the difference between the predicted value and the actual intensity, which was used as the optimization value to improve the accuracy of the prediction results of the characteristic values of the subsequent bearing capacity. Then, by calculating the characteristic parameters of foundation mechanics and establishing the boundary conditions of foundation bearing capacity, the mathematical model of foundation bearing capacity is constructed, so as to complete the analysis of the mechanical characteristics of foundation bearing capacity. The analysis results and foundation strength prediction parameters are input into the RBF neural network model. On the basis of optimizing parameter weights by the improved Relief algorithm, the prediction results of characteristic values of foundation bearing capacity are obtained by using the hyperparameters of THE RBF neural network algorithm. Experimental results show that the prediction results of this method are always in a controllable range, and the prediction error rate is between 1.21% and 1.35%, and the prediction time is between 30.1 min and 32.5 min, indicating that this method has high prediction accuracy and timeliness.
{"title":"Prediction Method of Characteristic Value of Foundation Bearing Capacity Based on Machine Learning Algorithm","authors":"Xue Xiao, Zheng Yangbing, Wang Xin","doi":"10.13052/ejcm2642-2085.3122","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3122","url":null,"abstract":"In this paper, a prediction method of characteristic value of foundation bearing capacity based on machine learning algorithm is proposed. Firstly, the influencing factors of foundation bearing capacity are analyzed, and then the prediction parameters of foundation pressure strength and foundation strength are calculated. The prediction error was obtained by comparing the difference between the predicted value and the actual intensity, which was used as the optimization value to improve the accuracy of the prediction results of the characteristic values of the subsequent bearing capacity. Then, by calculating the characteristic parameters of foundation mechanics and establishing the boundary conditions of foundation bearing capacity, the mathematical model of foundation bearing capacity is constructed, so as to complete the analysis of the mechanical characteristics of foundation bearing capacity. The analysis results and foundation strength prediction parameters are input into the RBF neural network model. On the basis of optimizing parameter weights by the improved Relief algorithm, the prediction results of characteristic values of foundation bearing capacity are obtained by using the hyperparameters of THE RBF neural network algorithm. Experimental results show that the prediction results of this method are always in a controllable range, and the prediction error rate is between 1.21% and 1.35%, and the prediction time is between 30.1 min and 32.5 min, indicating that this method has high prediction accuracy and timeliness.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44088805","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 : 2022-08-13DOI: 10.13052/ejcm2642-2085.3123
Long Chen, D. Feng, Y. Yu, Yunfeng Zeng
In order to improve the safety of linear motor metro operation, the wheel rail wear prediction and dynamic performance analysis of linear motor metro are carried out. Firstly, the working principle and evolution process of the linear motor are analyzed, and the traveling wave magnetic field and slip ratio of the linear motor are calculated. Secondly, the friction principle between wheel and rail is analyzed, and the running data of wheel and rail area are collected by MiniProf series profiler. By calculating the wear energy flow density and wear mass flow density of wheel rail contact surface, the relationship between wear coefficient and energy flow density is obtained, and the wheel rail wear area is obtained, so as to complete the prediction of wheel rail wear. Finally, the running resistance of Metro is analyzed, including mechanical resistance and aerodynamic resistance. Combined with the calculation results of Metro kinetic energy and electromagnetic, the position of linear motor is obtained by modal superposition method in the elastic coordinate system, and the dynamic equation of linear motor Metro is constructed to complete the dynamic performance analysis of Metro. The experimental results show that this research method can accurately predict the wear of linear motor metro, and can study the running stability of Metro from the two aspects of horizontal stability and derailment coefficient.
{"title":"Wheel Rail Wear Prediction and Dynamic Performance Analysis of Linear Metro","authors":"Long Chen, D. Feng, Y. Yu, Yunfeng Zeng","doi":"10.13052/ejcm2642-2085.3123","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3123","url":null,"abstract":"In order to improve the safety of linear motor metro operation, the wheel rail wear prediction and dynamic performance analysis of linear motor metro are carried out. Firstly, the working principle and evolution process of the linear motor are analyzed, and the traveling wave magnetic field and slip ratio of the linear motor are calculated. Secondly, the friction principle between wheel and rail is analyzed, and the running data of wheel and rail area are collected by MiniProf series profiler. By calculating the wear energy flow density and wear mass flow density of wheel rail contact surface, the relationship between wear coefficient and energy flow density is obtained, and the wheel rail wear area is obtained, so as to complete the prediction of wheel rail wear. Finally, the running resistance of Metro is analyzed, including mechanical resistance and aerodynamic resistance. Combined with the calculation results of Metro kinetic energy and electromagnetic, the position of linear motor is obtained by modal superposition method in the elastic coordinate system, and the dynamic equation of linear motor Metro is constructed to complete the dynamic performance analysis of Metro. The experimental results show that this research method can accurately predict the wear of linear motor metro, and can study the running stability of Metro from the two aspects of horizontal stability and derailment coefficient.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48603999","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 : 2022-07-02DOI: 10.13052/ejcm2642-2085.3121
A. Oudrane, B. Aour, M. Hamouda
The purpose of this work is to design computer codes to estimate the different thermal exchanges of the facades of a habitable envelope with its environment in order to optimize thermal comfort. This optimization is based on the use of real climate data from the region under consideration. To achieve this goal, we have developed five fundamental codes in FORTRAN language. The first code consists in Modelling the flow of the heat transfer fluid in the heating slab pipe. The second is designed to model the heat transfer by conduction within the concrete slab. The third is developed for the Modelling of thermal exchanges in a habitable envelope assimilated to a parallelepipedal cavity based on the nodal method. The fourth code is reserved for the Modelling of solar radiation by evaluating the wage flux density on different positions of the walls. The fifth and last code is dedicated to the evaluation of the perfect thermal coupling between the concrete slab and the heat transfer fluid pipes. The validation of the models implemented in the calculation codes was made on the basis of data measured recently for a clear sky of solar radiation at the radiometric station of the renewable energies research unit in the Saharan environment URER’MS of Adrar. The results obtained showed a very good agreement between the calculated values using the computational codes developed and those measured by the radiometric station of the URER’MS during the typical day.
{"title":"The Implementation of Numerical Codes for the Analysis of Solar Flux Inputs and the Optimization of Thermal Comfort for a Monobloc Habitat","authors":"A. Oudrane, B. Aour, M. Hamouda","doi":"10.13052/ejcm2642-2085.3121","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3121","url":null,"abstract":"The purpose of this work is to design computer codes to estimate the different thermal exchanges of the facades of a habitable envelope with its environment in order to optimize thermal comfort. This optimization is based on the use of real climate data from the region under consideration. To achieve this goal, we have developed five fundamental codes in FORTRAN language. The first code consists in Modelling the flow of the heat transfer fluid in the heating slab pipe. The second is designed to model the heat transfer by conduction within the concrete slab. The third is developed for the Modelling of thermal exchanges in a habitable envelope assimilated to a parallelepipedal cavity based on the nodal method. The fourth code is reserved for the Modelling of solar radiation by evaluating the wage flux density on different positions of the walls. The fifth and last code is dedicated to the evaluation of the perfect thermal coupling between the concrete slab and the heat transfer fluid pipes. The validation of the models implemented in the calculation codes was made on the basis of data measured recently for a clear sky of solar radiation at the radiometric station of the renewable energies research unit in the Saharan environment URER’MS of Adrar. The results obtained showed a very good agreement between the calculated values using the computational codes developed and those measured by the radiometric station of the URER’MS during the typical day.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46489588","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 : 2022-05-07DOI: 10.13052/ejcm2642-2085.3112
SHUENN-YIH CHANG*
An unusual stability property is found for a structure-dependent integration method since it exhibits a different nonlinearity interval of unconditional stability for zero and nonzero damping. Although it is unconditionally stable for the systems of stiffness softening and invariant as well as most systems of stiffness hardening, an unstable solution that is unexpected is obtained as it is applied to solve damped stiffness hardening systems. It is found herein that a nonlinearity interval of unconditional stability for a structure-dependent method may be drastically shrunk for nonzero damping when compared to zero damping. In fact, it will become conditionally stable for any damped stiffness hardening systems. This might significantly restrict its applications. An effective scheme is proposed to surmount this difficulty by introducing a stability factor into the structure-dependent coefficients of the integration method. This factor can effectively amplify the nonlinearity intervals of unconditional stability for structure-dependent methods. A large stability factor will result in a large nonlinearity interval of unconditional stability. However, it also introduces more period distortion. Consequently, a stability factor must be appropriately selected for accurate integration. After choosing a proper stability factor, a structure-dependent method can be widely and easily applied to solve general structural dynamic problems.
{"title":"An Unusual Damped Stability Property and its Remedy for an Integration Method","authors":"SHUENN-YIH CHANG*","doi":"10.13052/ejcm2642-2085.3112","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3112","url":null,"abstract":"An unusual stability property is found for a structure-dependent integration method since it exhibits a different nonlinearity interval of unconditional stability for zero and nonzero damping. Although it is unconditionally stable for the systems of stiffness softening and invariant as well as most systems of stiffness hardening, an unstable solution that is unexpected is obtained as it is applied to solve damped stiffness hardening systems. It is found herein that a nonlinearity interval of unconditional stability for a structure-dependent method may be drastically shrunk for nonzero damping when compared to zero damping. In fact, it will become conditionally stable for any damped stiffness hardening systems. This might significantly restrict its applications. An effective scheme is proposed to surmount this difficulty by introducing a stability factor into the structure-dependent coefficients of the integration method. This factor can effectively amplify the nonlinearity intervals of unconditional stability for structure-dependent methods. A large stability factor will result in a large nonlinearity interval of unconditional stability. However, it also introduces more period distortion. Consequently, a stability factor must be appropriately selected for accurate integration. After choosing a proper stability factor, a structure-dependent method can be widely and easily applied to solve general structural dynamic problems.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43004794","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 : 2022-05-07DOI: 10.13052/ejcm2642-2085.3115
M. Seabra, Ana Costa
A methodology based on Machine Learning, namely Fully Connected Neural Networks, is proposed to replace traditional parameter calibration strategies. In particular, the relation between hardness, yield strength and tensile strength is explored. The proposed methodology is used to predict the yield strength and the tensile strength of a Super Duplex Stainless Steel that was not included in the neural network training data base. Moreover, it is also used to determine such material parameters for individual microstructural phases, which feed a multiscale Finite Element simulation. The methodology is experimentally validated.
{"title":"Material Model Calibration Using Machine Learning: A Comparative Study","authors":"M. Seabra, Ana Costa","doi":"10.13052/ejcm2642-2085.3115","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3115","url":null,"abstract":"A methodology based on Machine Learning, namely Fully Connected Neural Networks, is proposed to replace traditional parameter calibration strategies. In particular, the relation between hardness, yield strength and tensile strength is explored. The proposed methodology is used to predict the yield strength and the tensile strength of a Super Duplex Stainless Steel that was not included in the neural network training data base. Moreover, it is also used to determine such material parameters for individual microstructural phases, which feed a multiscale Finite Element simulation. The methodology is experimentally validated.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43351604","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 : 2022-05-07DOI: 10.13052/ejcm2642-2085.3113
M. Azhdarzadeh, R. Jahangiri, A. Allahverdizadeh, B. Dadashzadeh, Ramin Nabati
In this paper, nonlinear and nonlocal thermo-elastic behavior of a microtube reinforced by Functionally Distributed Carbon Nanotubes, with internal and external piezoelectric layers, in the presence of nonlinear viscoelastic-Hetenyi foundation, and axial fluid flow inside the microtube is studied. Nonlinear partial differential equations governing the system are derived using Reddy’s third-order shear deformations theory along with the Von-Karman theory including the effect of fluid viscosity. Then, the equations are converted to time-dependent ordinary nonlinear equations using the Galerkin method. Afterward, the governing equations of the microtube’s lateral displacements are solved using the multiple scales method. The analysis of the piezoelectric’s parametric resonance is performed by obtaining trivial and nontrivial stationary solutions and plotting characteristic curves of the frequency response and voltage response. At the end, the effect of different parameters including the flow velocity, excitation voltage, parameters of the foundation, viscosity parameter, thermal loading and nanotubes’ volume fraction index on the nonlinear behavior of the system, under parametric resonance condition, is investigated.
{"title":"Investigation of Nonlinear Thermo-Elastic Behavior of Fluid Conveying Piezoelectric Microtube Reinforced by Functionally Distributed Carbon Nanotubes on Viscoelastic-Hetenyi Foundation","authors":"M. Azhdarzadeh, R. Jahangiri, A. Allahverdizadeh, B. Dadashzadeh, Ramin Nabati","doi":"10.13052/ejcm2642-2085.3113","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3113","url":null,"abstract":"In this paper, nonlinear and nonlocal thermo-elastic behavior of a microtube reinforced by Functionally Distributed Carbon Nanotubes, with internal and external piezoelectric layers, in the presence of nonlinear viscoelastic-Hetenyi foundation, and axial fluid flow inside the microtube is studied. Nonlinear partial differential equations governing the system are derived using Reddy’s third-order shear deformations theory along with the Von-Karman theory including the effect of fluid viscosity. Then, the equations are converted to time-dependent ordinary nonlinear equations using the Galerkin method. Afterward, the governing equations of the microtube’s lateral displacements are solved using the multiple scales method. The analysis of the piezoelectric’s parametric resonance is performed by obtaining trivial and nontrivial stationary solutions and plotting characteristic curves of the frequency response and voltage response. At the end, the effect of different parameters including the flow velocity, excitation voltage, parameters of the foundation, viscosity parameter, thermal loading and nanotubes’ volume fraction index on the nonlinear behavior of the system, under parametric resonance condition, is investigated.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47345239","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 : 2022-05-07DOI: 10.13052/ejcm2642-2085.3114
D. Hieu
This paper represents the nonlinear bending and free vibration analysis of a simply supported imperfect functionally graded (FG) microplate resting on an elastic foundation based on the modified couple stress theory and the Kirchhoff plate theory (KPT) together with the von-Kármán’s geometrical nonlinearity. The FG microplates with even and uneven distributions of porosities are considered. Analytical solutions for the nonlinear bending and free vibration are obtained. Comparing the obtained results with the published one in the literature shows the accuracy of the current solutions. Numerical examples are further presented to investigate the effects of the material length scale parameter to thickness ratio, the length to thickness ratio, the power-law index and the elastic foundation on the nonlinear bending and free vibration responses of the FG microplate.
{"title":"Nonlinear Bending and Vibration Analysis of Imperfect Functionally Graded Microplate with Porosities Resting on Elastic Foundation Via the Modified Couple Stress Theory","authors":"D. Hieu","doi":"10.13052/ejcm2642-2085.3114","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3114","url":null,"abstract":"This paper represents the nonlinear bending and free vibration analysis of a simply supported imperfect functionally graded (FG) microplate resting on an elastic foundation based on the modified couple stress theory and the Kirchhoff plate theory (KPT) together with the von-Kármán’s geometrical nonlinearity. The FG microplates with even and uneven distributions of porosities are considered. Analytical solutions for the nonlinear bending and free vibration are obtained. Comparing the obtained results with the published one in the literature shows the accuracy of the current solutions. Numerical examples are further presented to investigate the effects of the material length scale parameter to thickness ratio, the length to thickness ratio, the power-law index and the elastic foundation on the nonlinear bending and free vibration responses of the FG microplate.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43038023","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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