Xiaolin Huang, Jiahen Wang, Nengguo Wei, Cheng Wang, Binjun Ma
In this study, the buckling and vibration of a sigmoid functionally graded material (S-FGM) shells are investigated. Two types of porosity distributions, even and uneven, are taken into account. The material properties are estimated by a new modified rule of mixture. In the framework of the classic thin shell theory, the governing equations are derived and Galerkin’s integrate technique is employed to compute the critical load and natural frequency of porous S-FGM shells. The influence of pores, ceramic mass fraction and materials power index are discussed in detail.
{"title":"Buckling and vibration of porous sigmoid functionally graded conical shells","authors":"Xiaolin Huang, Jiahen Wang, Nengguo Wei, Cheng Wang, Binjun Ma","doi":"10.15632/jtam-pl/168072","DOIUrl":"https://doi.org/10.15632/jtam-pl/168072","url":null,"abstract":"In this study, the buckling and vibration of a sigmoid functionally graded material (S-FGM) shells are investigated. Two types of porosity distributions, even and uneven, are taken into account. The material properties are estimated by a new modified rule of mixture. In the framework of the classic thin shell theory, the governing equations are derived and Galerkin’s integrate technique is employed to compute the critical load and natural frequency of porous S-FGM shells. The influence of pores, ceramic mass fraction and materials power index are discussed in detail.","PeriodicalId":49980,"journal":{"name":"Journal of Theoretical and Applied Mechanics","volume":"81 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90675386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, a plate structure containing elliptical embedded cracks loaded under high temperature is studied. The constraint effect and creep crack initiation of the plate containing embedded cracks are discussed by using the finite element method based on the creep ductility exhaustion model. It is indicated that the highest constraint level or the load-independent parameter Q ∗ is observed at the endpoint of the ellipse major axis of an elliptical embedded crack, and the constraint levels increase with crack length or depth, which represents a worse condition for the structure, such as higher stress concentration and greater danger of failure for a larger crack depth ratio a/t or crack length ratio a/c . Moreover, under the creep condition, the embedded crack with a larger a/t , a/c or loadings is accompanied with a higher crack driving force, which can accelerate creep damage, creep cracking initiation (CCI) and shorten the creep crack initiation (CCI) time. Additionally, an empirical prediction equation and engineering approach to the constraint parameter and the CCI time for elliptical embedded cracks are proposed, and the engineering approach to the CCI time is validated.
{"title":"Study on constraint effect and creep crack initiation of plate containing elliptical embedded cracks","authors":"Dongquan Wu, Zixiang Liu, Yupeng Li, Dinghe Li, Zhiqiang Zhang","doi":"10.15632/jtam-pl/166338","DOIUrl":"https://doi.org/10.15632/jtam-pl/166338","url":null,"abstract":"In this study, a plate structure containing elliptical embedded cracks loaded under high temperature is studied. The constraint effect and creep crack initiation of the plate containing embedded cracks are discussed by using the finite element method based on the creep ductility exhaustion model. It is indicated that the highest constraint level or the load-independent parameter Q ∗ is observed at the endpoint of the ellipse major axis of an elliptical embedded crack, and the constraint levels increase with crack length or depth, which represents a worse condition for the structure, such as higher stress concentration and greater danger of failure for a larger crack depth ratio a/t or crack length ratio a/c . Moreover, under the creep condition, the embedded crack with a larger a/t , a/c or loadings is accompanied with a higher crack driving force, which can accelerate creep damage, creep cracking initiation (CCI) and shorten the creep crack initiation (CCI) time. Additionally, an empirical prediction equation and engineering approach to the constraint parameter and the CCI time for elliptical embedded cracks are proposed, and the engineering approach to the CCI time is validated.","PeriodicalId":49980,"journal":{"name":"Journal of Theoretical and Applied Mechanics","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82933980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Leyu Wei, Xinmeng Liu, Jie Yang, Linjian Shangguan, Xingxing Wang, Jizhe Mao
The suspension hole of a gearbox case was cracked after the mining test vehicle has covered 7000km. In order to analyze and solve this problem, in this paper, based on the modal analysis of the suspension system and failure analysis of the faulty parts, the finite element model of the powertrain system was established using Ansys, and strength analysis of the gearbox case was carried out. According to the analysis results, improvement and optimization measures were proposed. The analysis results show that the maximum stress of the optimized gearbox case was reduced by 6.9%, and the test vehicle could operate for 50 000km without failure after the improvement, which verified the effectiveness of those measures. Accumulating experience in the gearbox case design and simulation, modal analysis and finite element analysis were combined to quickly identify the failure causes of the suspension support hole, and targeted improvement measures were taken, which effectively shortened the research and development cycle and saved production costs.
{"title":"Failure analysis and optimization design of suspension support holes for gearbox cases","authors":"Leyu Wei, Xinmeng Liu, Jie Yang, Linjian Shangguan, Xingxing Wang, Jizhe Mao","doi":"10.15632/jtam-pl/167475","DOIUrl":"https://doi.org/10.15632/jtam-pl/167475","url":null,"abstract":"The suspension hole of a gearbox case was cracked after the mining test vehicle has covered 7000km. In order to analyze and solve this problem, in this paper, based on the modal analysis of the suspension system and failure analysis of the faulty parts, the finite element model of the powertrain system was established using Ansys, and strength analysis of the gearbox case was carried out. According to the analysis results, improvement and optimization measures were proposed. The analysis results show that the maximum stress of the optimized gearbox case was reduced by 6.9%, and the test vehicle could operate for 50 000km without failure after the improvement, which verified the effectiveness of those measures. Accumulating experience in the gearbox case design and simulation, modal analysis and finite element analysis were combined to quickly identify the failure causes of the suspension support hole, and targeted improvement measures were taken, which effectively shortened the research and development cycle and saved production costs.","PeriodicalId":49980,"journal":{"name":"Journal of Theoretical and Applied Mechanics","volume":"34 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86072521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, a software has been developed for calculating static strength of bolted steel plates. This software has been developed by adding equations covering the bending moment that occurs during a tensile test as well as under real loading conditions. In order to test the accuracy of this program, 5 samples with the M6 bolt connection were prepared. In addition, the simulation result was compared with the experimental work performed with tensile tests and the finite element analysis made in Ansys.
{"title":"Experimental and numerical analysis of bolted two plates using a developed shear theory","authors":"Kursat Tanriver, M. Ay","doi":"10.15632/jtam-pl/166533","DOIUrl":"https://doi.org/10.15632/jtam-pl/166533","url":null,"abstract":"In this study, a software has been developed for calculating static strength of bolted steel plates. This software has been developed by adding equations covering the bending moment that occurs during a tensile test as well as under real loading conditions. In order to test the accuracy of this program, 5 samples with the M6 bolt connection were prepared. In addition, the simulation result was compared with the experimental work performed with tensile tests and the finite element analysis made in Ansys.","PeriodicalId":49980,"journal":{"name":"Journal of Theoretical and Applied Mechanics","volume":"5 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79905951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shaoqi Li, Zhanping Yan, Yongchang Cui, Xueke Hou, Zi-Jun Wang
To study the dynamic response of roads under non-stationary random excitation, a dynamic differential equation is constructed firstly based on a two-axle half car model, and white noise to simulate road roughness is then filtered. Finally, non-stationary responses of different vehicle acceleration conditions are obtained. An infinite multi-layer plate on a viscoelastic half-space foundation as a model of the road structure and an analytical solution for the road dynamic response are obtained. Based on a numerical example, the dynamic response of a four-layer road model under vehicle loads is discussed. The study fills the gap in the theory of multi-wheel vehicle models.
{"title":"An unsteady vehicle-road coupling dynamic response of a multi-layer plate on a viscoelastic half-space foundation","authors":"Shaoqi Li, Zhanping Yan, Yongchang Cui, Xueke Hou, Zi-Jun Wang","doi":"10.15632/jtam-pl/166652","DOIUrl":"https://doi.org/10.15632/jtam-pl/166652","url":null,"abstract":"To study the dynamic response of roads under non-stationary random excitation, a dynamic differential equation is constructed firstly based on a two-axle half car model, and white noise to simulate road roughness is then filtered. Finally, non-stationary responses of different vehicle acceleration conditions are obtained. An infinite multi-layer plate on a viscoelastic half-space foundation as a model of the road structure and an analytical solution for the road dynamic response are obtained. Based on a numerical example, the dynamic response of a four-layer road model under vehicle loads is discussed. The study fills the gap in the theory of multi-wheel vehicle models.","PeriodicalId":49980,"journal":{"name":"Journal of Theoretical and Applied Mechanics","volume":"31 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75620597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Griffith crack problem in bonded dissimilar half-planes is examined. To eliminate the unrealistic oscillatory stress near the interface crack tips, the interfacial transition zone is modeled by a very thin nonhomogeneous interlayer whose elastic properties vary continuously between the bonded materials and adhesive material. The interlayer thickness is assumed to be the sum of the maximum heights of asperities at the two bonded material surfaces. The crack problem is reduced to a set of Cauchy integral equations which can be solved numerically. The applicability of the generalized nonhomogeneous interlayer model is investigated by comparing it with the classical interface crack model.
{"title":"A Griffith crack model in a generalized nonhomogeneous interlayer of bonded dissimilar half-planes","authors":"A. Zhang, J. Lou, Baolin Wang, Ji Wang","doi":"10.15632/jtam-pl/166562","DOIUrl":"https://doi.org/10.15632/jtam-pl/166562","url":null,"abstract":"The Griffith crack problem in bonded dissimilar half-planes is examined. To eliminate the unrealistic oscillatory stress near the interface crack tips, the interfacial transition zone is modeled by a very thin nonhomogeneous interlayer whose elastic properties vary continuously between the bonded materials and adhesive material. The interlayer thickness is assumed to be the sum of the maximum heights of asperities at the two bonded material surfaces. The crack problem is reduced to a set of Cauchy integral equations which can be solved numerically. The applicability of the generalized nonhomogeneous interlayer model is investigated by comparing it with the classical interface crack model.","PeriodicalId":49980,"journal":{"name":"Journal of Theoretical and Applied Mechanics","volume":"10 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87466195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, the multiaxial ductility factor was analyzed based on the power-law creep grain-boundary cavities growth theory under multiaxial stress states. Based on this theory, the theoretical cavities growth rates under a multiaxial stress state were discussed and the predicting model of a stress-state parameter α was revised by using an empirical fitting expression denoted as α Wu , which exhibited a good agreement to analytical results of the stress-state parameter α and multiaxial cavities growth rates. Then, according to the relationship between uniaxial and multiaxial creep failure strain, a new empirical predicting model of multiaxial ductility factor MDF Wu was established which involved the multiaxial parameter α Wu and uniaxial parameter α 0 . Besides, the theoretical model of multiaxial ductility factor MDF could also be established. By fitting the theoretical values of MDF , another predicting model MDF WM was proposed. The development of two multiaxial ductility factor predicting models could be achieved. Finally, predictions of these two novel multiaxial ductility factor models and the Cocks-Ashby as well as Wen-Tu model were compared with experimental data, and the prediction accuracy of MDF Wu and MDF WM models was significantly improved, especially for the latter one.
{"title":"The development of two multiaxial ductility factor predicting models based on creep cavity growth theory","authors":"Dongquan Wu, Yupeng Li, Zixiang Liu, Dinghe Li","doi":"10.15632/jtam-pl/166369","DOIUrl":"https://doi.org/10.15632/jtam-pl/166369","url":null,"abstract":"In this study, the multiaxial ductility factor was analyzed based on the power-law creep grain-boundary cavities growth theory under multiaxial stress states. Based on this theory, the theoretical cavities growth rates under a multiaxial stress state were discussed and the predicting model of a stress-state parameter α was revised by using an empirical fitting expression denoted as α Wu , which exhibited a good agreement to analytical results of the stress-state parameter α and multiaxial cavities growth rates. Then, according to the relationship between uniaxial and multiaxial creep failure strain, a new empirical predicting model of multiaxial ductility factor MDF Wu was established which involved the multiaxial parameter α Wu and uniaxial parameter α 0 . Besides, the theoretical model of multiaxial ductility factor MDF could also be established. By fitting the theoretical values of MDF , another predicting model MDF WM was proposed. The development of two multiaxial ductility factor predicting models could be achieved. Finally, predictions of these two novel multiaxial ductility factor models and the Cocks-Ashby as well as Wen-Tu model were compared with experimental data, and the prediction accuracy of MDF Wu and MDF WM models was significantly improved, especially for the latter one.","PeriodicalId":49980,"journal":{"name":"Journal of Theoretical and Applied Mechanics","volume":"60 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80890743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A long-term discontinuous development of the plastic zone and broken zone of weakly cemented surrounding rock is the main reason for instability of the surrounding rock of a roadway. The load-bearing support concept of “allowable deformation + releasable pressure + limited deformation” for a weakly cemented soft rock roadway is proposed, and an “allow-release-limit” support structure mechanical model with U-shaped steel as the main body is established. Anchoring control measures of “U-shaped steel + flexible material wall backfill + key parts strengthening” can solve problems of large deformation and long deformation duration of weakly cemented roadways.
{"title":"Instability mechanism and anchoring control technology of expansive weakly cemented soft rock roadway","authors":"W. Zhang","doi":"10.15632/jtam-pl/166276","DOIUrl":"https://doi.org/10.15632/jtam-pl/166276","url":null,"abstract":"A long-term discontinuous development of the plastic zone and broken zone of weakly cemented surrounding rock is the main reason for instability of the surrounding rock of a roadway. The load-bearing support concept of “allowable deformation + releasable pressure + limited deformation” for a weakly cemented soft rock roadway is proposed, and an “allow-release-limit” support structure mechanical model with U-shaped steel as the main body is established. Anchoring control measures of “U-shaped steel + flexible material wall backfill + key parts strengthening” can solve problems of large deformation and long deformation duration of weakly cemented roadways.","PeriodicalId":49980,"journal":{"name":"Journal of Theoretical and Applied Mechanics","volume":"45 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75106275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In practical computational fluid dynamics simulations around industrial products with complex surface shapes, the robustness of preprocessing to “dirty” geometry is an important issue. The dirty STL (Standard Triangle Language) data contains errors such as gaps between facets, overlapping of facets, and flipping of normal vectors. These errors in the STL data are difficult to avoid in 3D modeling of complex geometry. Using a Cartesian grid is advantageous to the boundary-fitted grid in the aspect of preprocessing for dirty STL files. In this study, a robust and automatic generation method of a signed distance function for the preprocessing of Cartesian grid solvers is proposed. To ensure robustness to the complex and dirty STL data, the proposed method uses information of all STL facets to determine each grid point. The proposed preprocessing method is verified by numerical simulation of the flow around the NASA common research model.
{"title":"Robust generation method of a signed distance function for preprocessing of cartesian-grid-based CFD","authors":"Y. Takeda, K. Ueno, Y. Takahashi, Karin Matsubara","doi":"10.15632/jtam-pl/165954","DOIUrl":"https://doi.org/10.15632/jtam-pl/165954","url":null,"abstract":"In practical computational fluid dynamics simulations around industrial products with complex surface shapes, the robustness of preprocessing to “dirty” geometry is an important issue. The dirty STL (Standard Triangle Language) data contains errors such as gaps between facets, overlapping of facets, and flipping of normal vectors. These errors in the STL data are difficult to avoid in 3D modeling of complex geometry. Using a Cartesian grid is advantageous to the boundary-fitted grid in the aspect of preprocessing for dirty STL files. In this study, a robust and automatic generation method of a signed distance function for the preprocessing of Cartesian grid solvers is proposed. To ensure robustness to the complex and dirty STL data, the proposed method uses information of all STL facets to determine each grid point. The proposed preprocessing method is verified by numerical simulation of the flow around the NASA common research model.","PeriodicalId":49980,"journal":{"name":"Journal of Theoretical and Applied Mechanics","volume":"14 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87705198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to effectively calculate dynamic characteristics of a sealed ends squeeze film damper (SFD) under the influence of the inertial force, a computational fluid dynamics model of the sealed ends SFD is established. The fluid inertia coefficient of SFD is investigated by using an energy approximation method. Both the theoretical calculation and numerical simulation are conducted to analyze the effects of eccentricity ratio and whirling frequency on stiffness and damping. In this research, the oil film inertia force of the sealed ends SFD is solved by using long bearing approximation (LBA) theory, which provides guidance for the design and application of the sealed ends SFD.
{"title":"Analysis of dynamic characteristics of a sealed ends squeeze film damper considering the fluid inertia force","authors":"Haiming Zhou, Yangguang Cang, Yu Qi Zhang, Chao Guo","doi":"10.15632/jtam-pl/165937","DOIUrl":"https://doi.org/10.15632/jtam-pl/165937","url":null,"abstract":"In order to effectively calculate dynamic characteristics of a sealed ends squeeze film damper (SFD) under the influence of the inertial force, a computational fluid dynamics model of the sealed ends SFD is established. The fluid inertia coefficient of SFD is investigated by using an energy approximation method. Both the theoretical calculation and numerical simulation are conducted to analyze the effects of eccentricity ratio and whirling frequency on stiffness and damping. In this research, the oil film inertia force of the sealed ends SFD is solved by using long bearing approximation (LBA) theory, which provides guidance for the design and application of the sealed ends SFD.","PeriodicalId":49980,"journal":{"name":"Journal of Theoretical and Applied Mechanics","volume":"113 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89299537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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