Pub Date : 2023-05-03DOI: 10.13052/ejcm2642-2085.31564
Yin Zhenyu
In recent years, earthquakes have occurred frequently at home and abroad, causing huge losses to the local society. Therefore, it is important to study the mechanical response of foundations under earthquakes. In this paper, firstly, gravel piles are selected as soft ground improvement materials, and A single bulk material pile section and a peripile soil section within the influence of a single pile are considered as a study unit, and the pore water discharge from the consolidation process is equal to the volume reduction of the unit, considering the consolidation deformation of the pile body, the composite foundation consolidation equation is derived, and the consolidation equation is solved by the separation variable method through the isostrain assumption and initial boundary conditions, and the average superporous water pressure of the soil between the body and the pile is obtained. Then, a more realistic non-uniform ground motion input method is adopted, and the seismic fluctuations are converted into equivalent loads on artificial boundary nodes through the Matlab program, and the equivalent loads are applied to the established viscoelastic artificial boundary by OpenSees software to realize ground motion input. Finally, a mechanical analysis model is established by hypothesis, and with the help of mode orthogonal theory and Hilbert yellow transform, the calculation method of ground seismic mechanical response based on non-uniform ground motion input is obtained. The results show that the effect of gravel pile encryption can reduce the accumulation rate and peak of super-static pore pressure during vibration, and the surface settlement of the site is reduced by 40–50% and the surface lateral shift is reduced by 30–50% after encryption; the drainage effect has a significant effect on reducing the accumulation rate of super-static pore pressure and the post-earthquake dissipation time of the soil during vibration, and the surface settlement is reduced by about 10–20% and the lateral shift is reduced by about 30–40% after increasing the drainage effect.
{"title":"Construction and Calculation Analysis of Mechanical Model of Crushed Rock Pile Treatment of Foundation Earthquake","authors":"Yin Zhenyu","doi":"10.13052/ejcm2642-2085.31564","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.31564","url":null,"abstract":"In recent years, earthquakes have occurred frequently at home and abroad, causing huge losses to the local society. Therefore, it is important to study the mechanical response of foundations under earthquakes. In this paper, firstly, gravel piles are selected as soft ground improvement materials, and A single bulk material pile section and a peripile soil section within the influence of a single pile are considered as a study unit, and the pore water discharge from the consolidation process is equal to the volume reduction of the unit, considering the consolidation deformation of the pile body, the composite foundation consolidation equation is derived, and the consolidation equation is solved by the separation variable method through the isostrain assumption and initial boundary conditions, and the average superporous water pressure of the soil between the body and the pile is obtained. Then, a more realistic non-uniform ground motion input method is adopted, and the seismic fluctuations are converted into equivalent loads on artificial boundary nodes through the Matlab program, and the equivalent loads are applied to the established viscoelastic artificial boundary by OpenSees software to realize ground motion input. Finally, a mechanical analysis model is established by hypothesis, and with the help of mode orthogonal theory and Hilbert yellow transform, the calculation method of ground seismic mechanical response based on non-uniform ground motion input is obtained. The results show that the effect of gravel pile encryption can reduce the accumulation rate and peak of super-static pore pressure during vibration, and the surface settlement of the site is reduced by 40–50% and the surface lateral shift is reduced by 30–50% after encryption; the drainage effect has a significant effect on reducing the accumulation rate of super-static pore pressure and the post-earthquake dissipation time of the soil during vibration, and the surface settlement is reduced by about 10–20% and the lateral shift is reduced by about 30–40% after increasing the drainage effect.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":"1 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43315013","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 : 2023-05-03DOI: 10.13052/ejcm2642-2085.31562
B. J. Akinbo, B. Olajuwon
This present investigation studies the effect of viscous dissipation in magnetohydrodynamics fluid flow over an exponential surface subject to the influence of thermal radiation and thermal diffusion. The coupled nonlinear guiding equations responsible for the flow, heat and mass transports presented as partial differential equations are revamped to the associated ordinary differential equation by application of the associated similarity variables and solved by Galerkin Weighted residual method (GWRM). The results of various parameters encountered are analyzed with graphs while the Sherwood number, Nussetl number, and local skin friction are computed and discussed. The study demonstrates, among other things, that the fluid has a strong thermal conductivity at low Prandtl numbers and that heat diffuses from the surface more quickly at low Prandtl numbers in comparison with the higher values.
{"title":"Viscous Dissipation Effect on Magnetohydrodynamics Fluid Flow Over an Exponential Surface with the Influence of Thermal Radiation and Thermal Diffusion","authors":"B. J. Akinbo, B. Olajuwon","doi":"10.13052/ejcm2642-2085.31562","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.31562","url":null,"abstract":"This present investigation studies the effect of viscous dissipation in magnetohydrodynamics fluid flow over an exponential surface subject to the influence of thermal radiation and thermal diffusion. The coupled nonlinear guiding equations responsible for the flow, heat and mass transports presented as partial differential equations are revamped to the associated ordinary differential equation by application of the associated similarity variables and solved by Galerkin Weighted residual method (GWRM). The results of various parameters encountered are analyzed with graphs while the Sherwood number, Nussetl number, and local skin friction are computed and discussed. The study demonstrates, among other things, that the fluid has a strong thermal conductivity at low Prandtl numbers and that heat diffuses from the surface more quickly at low Prandtl numbers in comparison with the higher values.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46568586","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 : 2023-05-03DOI: 10.13052/ejcm2642-2085.31561
SHUENN-YIH CHANG*
The first family of structure-dependent integration methods have been successfully developed for nonlinear dynamic analysis. Although its numerical properties were evaluated and its performance was numerically corroborated for both linear and nonlinear systems, its feasibility is still under debate due to the lack of a theoretical background. It seems that an eigen-based theory can provide a fundamental basis for the proof of the feasibility of structure-dependent integration methods. This can be manifested from each major stage of the development of structure-dependent integration methods. Therefore, the development of the first family of structure-dependent integration methods will be presented and the correlation between each major stage and an eigen-based theory will be explored and explained. Besides, this developing sequence can lay a typical procedure for developing a general structure-dependent integration method.
{"title":"Insight Into Feasibility of Structure-Dependent Methods for Dynamic Analysis","authors":"SHUENN-YIH CHANG*","doi":"10.13052/ejcm2642-2085.31561","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.31561","url":null,"abstract":"The first family of structure-dependent integration methods have been successfully developed for nonlinear dynamic analysis. Although its numerical properties were evaluated and its performance was numerically corroborated for both linear and nonlinear systems, its feasibility is still under debate due to the lack of a theoretical background. It seems that an eigen-based theory can provide a fundamental basis for the proof of the feasibility of structure-dependent integration methods. This can be manifested from each major stage of the development of structure-dependent integration methods. Therefore, the development of the first family of structure-dependent integration methods will be presented and the correlation between each major stage and an eigen-based theory will be explored and explained. Besides, this developing sequence can lay a typical procedure for developing a general structure-dependent integration method.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46604999","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 : 2023-02-06DOI: 10.13052/ejcm2642-2085.3143
Ihab Eddine Houalef, Ismail Bensaid, Ahmed Saimi, A. Cheikh
Present paper deals on the free vibration investigation of carbon nanotube-reinforced composite (CNTs) beams, based on refined third order shear deformation finite element beam theory. The particularity of this model is that, it can capture shear deformation effect without using of any shear correction factor by satisfying shear stress free at free edges. The carbon nanotubes are supposed to be immersed in a polymeric matrix with functionally graded pattern across the thickness direction of the beam, and their material properties are evaluated using the rule of mixture. The differential equations of motion and related boundary conditions are extracted using Lagrange’s principle and solved employing a robust numerical tool called, Differential Quadrature Finite Element Method (DQFEM) for the first time, with high convergence speed, fast calculus performance as well as a good numerical stability. The obtained results have been validated with those available in literature, in order to show the correctness of the present model. Afterwards, a deep parametric study is performed to examine the effects of various geometrical and material parameters on the vibration behavior of FG-CNTs beams.
{"title":"Free Vibration Analysis of Functionally Graded Carbon Nanotube-Reinforced Higher Order Refined Composite Beams Using Differential Quadrature Finite Element Method","authors":"Ihab Eddine Houalef, Ismail Bensaid, Ahmed Saimi, A. Cheikh","doi":"10.13052/ejcm2642-2085.3143","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3143","url":null,"abstract":"Present paper deals on the free vibration investigation of carbon nanotube-reinforced composite (CNTs) beams, based on refined third order shear deformation finite element beam theory. The particularity of this model is that, it can capture shear deformation effect without using of any shear correction factor by satisfying shear stress free at free edges. The carbon nanotubes are supposed to be immersed in a polymeric matrix with functionally graded pattern across the thickness direction of the beam, and their material properties are evaluated using the rule of mixture. The differential equations of motion and related boundary conditions are extracted using Lagrange’s principle and solved employing a robust numerical tool called, Differential Quadrature Finite Element Method (DQFEM) for the first time, with high convergence speed, fast calculus performance as well as a good numerical stability. The obtained results have been validated with those available in literature, in order to show the correctness of the present model. Afterwards, a deep parametric study is performed to examine the effects of various geometrical and material parameters on the vibration behavior of FG-CNTs beams.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47353198","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 : 2023-02-06DOI: 10.13052/ejcm2642-2085.3141
P. Joli, N. Azouz, Manel Ben Wezdou, J. Néji
The purpose of this paper is the modelling in large displacement of systems composed of a rigid platform suspended by flexible cables, as can be observed in lifting systems of a construction crane or in cable-driven parallel robots (CDPRs). A recent approach has been proposed in the literature to model the nonlinear behavior of a cable element based on three dimensional catenary elastic modelling and the general displacement control method (GDCM) as solver. In this paper, two modifications of this method are proposed to take into account the geometric constraints coupling the large displacements of the cable extremities. The first approach is to consider these constraints using penalty functions thus modifying the tangent stiffness matrix and the second method by adding external explicit elastic forces. These two methods are tested and compared by using numerical examples. The first method is numerically safer because it is not dependent on the poor numerical conditioning of the cable’stiffness matrix encountered when internal cable’s tension cannot balance the external forces.
{"title":"Nonlinear Analysis of Cable Structures with Geometric Constraints","authors":"P. Joli, N. Azouz, Manel Ben Wezdou, J. Néji","doi":"10.13052/ejcm2642-2085.3141","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3141","url":null,"abstract":"The purpose of this paper is the modelling in large displacement of systems composed of a rigid platform suspended by flexible cables, as can be observed in lifting systems of a construction crane or in cable-driven parallel robots (CDPRs). A recent approach has been proposed in the literature to model the nonlinear behavior of a cable element based on three dimensional catenary elastic modelling and the general displacement control method (GDCM) as solver. In this paper, two modifications of this method are proposed to take into account the geometric constraints coupling the large displacements of the cable extremities. The first approach is to consider these constraints using penalty functions thus modifying the tangent stiffness matrix and the second method by adding external explicit elastic forces. These two methods are tested and compared by using numerical examples. The first method is numerically safer because it is not dependent on the poor numerical conditioning of the cable’stiffness matrix encountered when internal cable’s tension cannot balance the external forces.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44554356","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 : 2023-02-06DOI: 10.13052/ejcm2642-2085.3142
Yangyang Wei, Huidi Guo, S. Zhang, Jingyuan Li, Yihan Wang, Chajuan Liu
The nodes of the object will show different degrees of deformation and displacement or even damage over time. The mesh structure is flexible and different mesh shapes and arrangements will affect the structural stiffness of the object. The unique structure of dragonfly wing veins allows the dragonfly to withstand pressures several times higher than itself and to fly freely. This study is based on dragonfly wing bionics to disassemble the structure of dragonfly wing vein geometry. And it aims to investigate the deflection under different geometries and three-dimensional spatial structures by using the drawing software Auto CAD to draw dragonfly sample graphics, the finite element software Hyper mesh to build the model and the solver OptiStruct to analyze the structure of wrinkling, arching deflection, z-direction maximum displacement, y-direction maximum rotation angle, combined displacement test under the different loads. The results show that: (1) The dragonfly wing vein mesh structure can enhance the stiffness under load. (2) In contrast, the displacement deformation of quadrilateral and combined hexagonal is smaller. (3) The structural stiffness of quadrilateral hexagon is enhanced as the height of wrinkling and arching increases. (4) The improvement of grid deflection with membrane structure is better than that without membrane structure. According to the above experimental results, the quadrilateral wrinkling and hexagonal arching structure has a significant improvement on the load bearing and deflection of the mesh, and has the potential to make structural optimization of the mesh series products, which is suitable for practical application and promotion.
{"title":"Bionic Mechanical Analysis of Dragonfly Wings: The Feasibility of Mesh Combination to Improve Structural Stiffness","authors":"Yangyang Wei, Huidi Guo, S. Zhang, Jingyuan Li, Yihan Wang, Chajuan Liu","doi":"10.13052/ejcm2642-2085.3142","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3142","url":null,"abstract":"The nodes of the object will show different degrees of deformation and displacement or even damage over time. The mesh structure is flexible and different mesh shapes and arrangements will affect the structural stiffness of the object. The unique structure of dragonfly wing veins allows the dragonfly to withstand pressures several times higher than itself and to fly freely. This study is based on dragonfly wing bionics to disassemble the structure of dragonfly wing vein geometry. And it aims to investigate the deflection under different geometries and three-dimensional spatial structures by using the drawing software Auto CAD to draw dragonfly sample graphics, the finite element software Hyper mesh to build the model and the solver OptiStruct to analyze the structure of wrinkling, arching deflection, z-direction maximum displacement, y-direction maximum rotation angle, combined displacement test under the different loads. The results show that: (1) The dragonfly wing vein mesh structure can enhance the stiffness under load. (2) In contrast, the displacement deformation of quadrilateral and combined hexagonal is smaller. (3) The structural stiffness of quadrilateral hexagon is enhanced as the height of wrinkling and arching increases. (4) The improvement of grid deflection with membrane structure is better than that without membrane structure. According to the above experimental results, the quadrilateral wrinkling and hexagonal arching structure has a significant improvement on the load bearing and deflection of the mesh, and has the potential to make structural optimization of the mesh series products, which is suitable for practical application and promotion.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48981824","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 : 2023-02-06DOI: 10.13052/ejcm2642-2085.3144
Wang Taiheng, Li Wei, C. Meng, Liu Bin, Wang Jun
In recent years, corrugated steel has been used in some domestic tunnel construction for its large section and high strength, and has become a new type of tunnel support structure. Corrugated steel mechanical properties will directly affect the stability of support structure. Therefore, the important thing is to choose the appropriate parameter to improve the mechanical performance of ripples. Parameters that affecting the mechanical properties of corrugated steel include wave height, corrugation thickness and wave distance. This massage will rely on the Qipan Mountain tunnel project, studying its fabricated corrugated steel supporting structure, and selects corrugated steel with different thicknesses, wave heights and corrugated spans for transient analysis. The largest deformation of corrugated steel under blasting shock is calculated by numerical simulation to react the corrugated steel mechanical properties, and then use the method of Entropy to determine the influence of different parameter values on mechanical performance of corrugated steel. The weight coefficient of wave thickness is 92.38%, the influence weight coefficient of wave height is 7.54%, and the influence weight coefficient of wave short is 0.07%. It is shows that the thickness has the greatest influence on the mechanical properties of the supporting structure, and the wave distance has no influence. Through the above analysis, the parameter design and stability design of corrugated steel support structure can be given some reference and help.
{"title":"Analysis of Factors Influencing Mechanical Properties of Corrugated Steel Based on Entropy Method","authors":"Wang Taiheng, Li Wei, C. Meng, Liu Bin, Wang Jun","doi":"10.13052/ejcm2642-2085.3144","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3144","url":null,"abstract":"In recent years, corrugated steel has been used in some domestic tunnel construction for its large section and high strength, and has become a new type of tunnel support structure. Corrugated steel mechanical properties will directly affect the stability of support structure. Therefore, the important thing is to choose the appropriate parameter to improve the mechanical performance of ripples. Parameters that affecting the mechanical properties of corrugated steel include wave height, corrugation thickness and wave distance. This massage will rely on the Qipan Mountain tunnel project, studying its fabricated corrugated steel supporting structure, and selects corrugated steel with different thicknesses, wave heights and corrugated spans for transient analysis. The largest deformation of corrugated steel under blasting shock is calculated by numerical simulation to react the corrugated steel mechanical properties, and then use the method of Entropy to determine the influence of different parameter values on mechanical performance of corrugated steel. The weight coefficient of wave thickness is 92.38%, the influence weight coefficient of wave height is 7.54%, and the influence weight coefficient of wave short is 0.07%. It is shows that the thickness has the greatest influence on the mechanical properties of the supporting structure, and the wave distance has no influence. Through the above analysis, the parameter design and stability design of corrugated steel support structure can be given some reference and help.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48213579","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 : 2022-11-26DOI: 10.13052/ejcm2642-2085.3133
Rundong Shen, Kechang Zhang, Jinyan Shi
Aiming at the problems that the features extracted from the traditional system operation state are not adaptive and the specific system operation state is difficult to match, a gearbox system operation state diagnosis method based on continuous wavelet transform (CWT) and two-dimensional convolutional neural network (CNN) is proposed. The method uses the continuous wavelet transform to construct the time-frequency map of the hydrodynamic system operating state signal, and uses it as the input to construct a convolutional neural network model, and forms a deep distributed system operating state feature expression through a multilayer convolutional pool. The structural parameters of each layer of the network are adjusted by the back propagation algorithm to establish an accurate mapping from the signal characteristics to the system operating state. In the experiments under different working conditions and different system operation states, the accuracy of system operation state recognition reaches 99.2%, which verifies the effectiveness of the method. Using this method of adaptively learning rich information in the signal can provide a basis for intelligent system operation state diagnosis.
{"title":"Research on Hydraulic Power System Operation Status Diagnosis Technology Based on Hybrid CNN Model","authors":"Rundong Shen, Kechang Zhang, Jinyan Shi","doi":"10.13052/ejcm2642-2085.3133","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3133","url":null,"abstract":"Aiming at the problems that the features extracted from the traditional system operation state are not adaptive and the specific system operation state is difficult to match, a gearbox system operation state diagnosis method based on continuous wavelet transform (CWT) and two-dimensional convolutional neural network (CNN) is proposed. The method uses the continuous wavelet transform to construct the time-frequency map of the hydrodynamic system operating state signal, and uses it as the input to construct a convolutional neural network model, and forms a deep distributed system operating state feature expression through a multilayer convolutional pool. The structural parameters of each layer of the network are adjusted by the back propagation algorithm to establish an accurate mapping from the signal characteristics to the system operating state. In the experiments under different working conditions and different system operation states, the accuracy of system operation state recognition reaches 99.2%, which verifies the effectiveness of the method. Using this method of adaptively learning rich information in the signal can provide a basis for intelligent system operation state diagnosis.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45559688","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 : 2022-11-26DOI: 10.13052/ejcm2642-2085.3134
Xiao Xue, Yangbin Zheng, Xin Wang
Due to its large axle load and high-density operation mode, heavy haul transportation has greatly improved the cargo transportation capacity, and is receiving unprecedented attention from all countries in the world. Since the development of heavy haul freight transport in China, wheel rail wear has been paid much attention, especially the use of heavy axle load locomotives on upgraded heavy haul lines, which makes reducing wheel rail wear and damage become a technical problem to be solved urgently. Considering that there are too many mechanical parameters involved in the prediction of heavy load wheel rail wear mechanical properties, the prediction accuracy is reduced. Therefore, this paper proposes a method based on GA-BP hybrid algorithm to predict the mechanical properties of heavy load wheel/rail wear. Hertz contact theory is used to simplify the wheel rail contact relationship, and the wheel rail contact model is established. According to the wheel/rail contact model, the expressions of heavy load wheel/rail in the case of vertical, horizontal, direction and gauge irregularity are analyzed, and based on this, a mechanical model of heavy load wheel/rail wear is established. In order to solve the problems of slow convergence speed and easy to fall into local optimum of BP neural network in the prediction of heavy load wheel/rail wear mechanical properties, the global convergence of genetic algorithm is used to optimize the BP network. According to the obtained mechanical parameters of heavy load wheel/rail wear, the mechanical parameters are input into the optimized model, and the relevant prediction results are output. So far, the research on the prediction method of heavy load wheel/rail wear mechanical properties based on GA-BP hybrid algorithm has been realized. The experiment is designed from three aspects of wear degree, hardness and tensile strength, and compared with the measured value, reference [4] method, reference [5] method and reference [6] method to verify the effectiveness of the proposed method. The experimental results show that the predicted results of wear degree, hardness and tensile strength by this method are closer to the measured results. It is proved that the proposed method has higher prediction accuracy and better practical application effect.
{"title":"Prediction Method of Heavy Load Wheel/Rail Wear Mechanical Properties Based on GA-BP Hybrid Algorithm","authors":"Xiao Xue, Yangbin Zheng, Xin Wang","doi":"10.13052/ejcm2642-2085.3134","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3134","url":null,"abstract":"Due to its large axle load and high-density operation mode, heavy haul transportation has greatly improved the cargo transportation capacity, and is receiving unprecedented attention from all countries in the world. Since the development of heavy haul freight transport in China, wheel rail wear has been paid much attention, especially the use of heavy axle load locomotives on upgraded heavy haul lines, which makes reducing wheel rail wear and damage become a technical problem to be solved urgently. Considering that there are too many mechanical parameters involved in the prediction of heavy load wheel rail wear mechanical properties, the prediction accuracy is reduced. Therefore, this paper proposes a method based on GA-BP hybrid algorithm to predict the mechanical properties of heavy load wheel/rail wear. Hertz contact theory is used to simplify the wheel rail contact relationship, and the wheel rail contact model is established. According to the wheel/rail contact model, the expressions of heavy load wheel/rail in the case of vertical, horizontal, direction and gauge irregularity are analyzed, and based on this, a mechanical model of heavy load wheel/rail wear is established. In order to solve the problems of slow convergence speed and easy to fall into local optimum of BP neural network in the prediction of heavy load wheel/rail wear mechanical properties, the global convergence of genetic algorithm is used to optimize the BP network. According to the obtained mechanical parameters of heavy load wheel/rail wear, the mechanical parameters are input into the optimized model, and the relevant prediction results are output. So far, the research on the prediction method of heavy load wheel/rail wear mechanical properties based on GA-BP hybrid algorithm has been realized. The experiment is designed from three aspects of wear degree, hardness and tensile strength, and compared with the measured value, reference [4] method, reference [5] method and reference [6] method to verify the effectiveness of the proposed method. The experimental results show that the predicted results of wear degree, hardness and tensile strength by this method are closer to the measured results. It is proved that the proposed method has higher prediction accuracy and better practical application effect.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45573933","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 : 2022-11-14DOI: 10.13052/ejcm2642-2085.3132
H. M. Abdalla
In this article, a direct transcription approach to the minimization of the volume of elastic straight beams undergoing plane deformation and subject to buckling loads is presented. In particular, the so-called pseudospectral method is employed, where state variables are approximated by Lagrange interpolating polynomials and static equations are collocated at Legendre-Gauss-Radau nonuniform mesh points. The resulting shape optimization problems are thus transcribed into constrained nonlinear programming problems, which in turn are solved by developed routines. Historical benchmark and academic problems such as simply supported beams subject to a concentrated compressing force, compressed and rotating cantilever beams and simply supported beams under a non-conservative follower distributed load are revisited and numerically solved under the conditions of plane deformation theory. Numerical solutions are discussed and compared to those obtained by the shooting method, which is largely employed for these problems, emphasizing how the proposed method could forecast optimal cross sectional area distributions within a unified fashion and without resorting to accurate guesses beforehand.
{"title":"Pseudospectral Approach to the Shape Optimization of Beams Under Buckling Constraints","authors":"H. M. Abdalla","doi":"10.13052/ejcm2642-2085.3132","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3132","url":null,"abstract":"In this article, a direct transcription approach to the minimization of the volume of elastic straight beams undergoing plane deformation and subject to buckling loads is presented. In particular, the so-called pseudospectral method is employed, where state variables are approximated by Lagrange interpolating polynomials and static equations are collocated at Legendre-Gauss-Radau nonuniform mesh points. The resulting shape optimization problems are thus transcribed into constrained nonlinear programming problems, which in turn are solved by developed routines. Historical benchmark and academic problems such as simply supported beams subject to a concentrated compressing force, compressed and rotating cantilever beams and simply supported beams under a non-conservative follower distributed load are revisited and numerically solved under the conditions of plane deformation theory. Numerical solutions are discussed and compared to those obtained by the shooting method, which is largely employed for these problems, emphasizing how the proposed method could forecast optimal cross sectional area distributions within a unified fashion and without resorting to accurate guesses beforehand.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44137114","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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