Chuanhui Cui, Z. Zhu, S. Chen, Q. Zheng, Jinfeng Chai, Xiancai Li
In numerically controlled grinding of aeroengine blades, a sharp change in a rotating shaft caused by a singular zone greatly reduces grinding precision and quality. This paper proposes an algorithm to optimize the tool-path that combines optimization of the C -axis rotation angle, a modification to the tool orientation and adjustments to the tool position by taking a four-array machine tool with two rotational axes ( B -axis and C -axis) as an example. The algorithm was verified using VERICUT software, furthermore, in machining experiments, the rotation amplitudes of the rotary axis in singular areas was effectively reduced, which ensured grinding quality of blades.
{"title":"A tool orientation smoothing method for five-axis machining to avoid singularity problems","authors":"Chuanhui Cui, Z. Zhu, S. Chen, Q. Zheng, Jinfeng Chai, Xiancai Li","doi":"10.15632/jtam-pl/157570","DOIUrl":"https://doi.org/10.15632/jtam-pl/157570","url":null,"abstract":"In numerically controlled grinding of aeroengine blades, a sharp change in a rotating shaft caused by a singular zone greatly reduces grinding precision and quality. This paper proposes an algorithm to optimize the tool-path that combines optimization of the C -axis rotation angle, a modification to the tool orientation and adjustments to the tool position by taking a four-array machine tool with two rotational axes ( B -axis and C -axis) as an example. The algorithm was verified using VERICUT software, furthermore, in machining experiments, the rotation amplitudes of the rotary axis in singular areas was effectively reduced, which ensured grinding quality of blades.","PeriodicalId":49980,"journal":{"name":"Journal of Theoretical and Applied Mechanics","volume":"51 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83526366","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}
Ran Li, Wenshu Wei, Hao Liu, Dalong Wang, Jian-Ding Ye, Shoubin Li, Wen Wang, Huigang Wu
{"title":"Comparative evaluation of wear behavior of tribo-pairs in reciprocating pumps with multiple materials under different conditions","authors":"Ran Li, Wenshu Wei, Hao Liu, Dalong Wang, Jian-Ding Ye, Shoubin Li, Wen Wang, Huigang Wu","doi":"10.15632/jtam-pl/157583","DOIUrl":"https://doi.org/10.15632/jtam-pl/157583","url":null,"abstract":"","PeriodicalId":49980,"journal":{"name":"Journal of Theoretical and Applied Mechanics","volume":"56 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84844871","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}
D. Ouzandja, M. Messaad, A. Berrabah, Mohamed Belhrizi
This paper shows the impact of material nonlinearity of a dam-foundation rock system on seismic performance of Oued Fodda concrete gravity dam, located at northwestern side of Algeria. For the purpose, a three-dimensional dam-foundation rock system finite element model is employed in analyses. The hydrodynamic interaction between reservoir water and dam-foundation system is implicitly taken into consideration by the Westergaard approach using surface finite elements added to dam-fluid and foundation-fluid interfaces. The concrete material model is used to present the cracking of dam concrete under a seismic load the using smeared crack approach based on the Willam and Warnke failure criterion. The materially nonlinear analysis for both dam concrete and foundation rock is performed using Drucker-Prager model. According to numerical results, tensile stresses and maximum strains reduce significantly in the materially nonlinear model. In addition, the cracking areas in the dam decrease also when material nonlinearity characteristics of the dam-foundation rock system is considered in analyses.
{"title":"Impact of material nonlinearity of dam-foundation rock system on seismic performance of concrete gravity dams","authors":"D. Ouzandja, M. Messaad, A. Berrabah, Mohamed Belhrizi","doi":"10.15632/jtam-pl/157571","DOIUrl":"https://doi.org/10.15632/jtam-pl/157571","url":null,"abstract":"This paper shows the impact of material nonlinearity of a dam-foundation rock system on seismic performance of Oued Fodda concrete gravity dam, located at northwestern side of Algeria. For the purpose, a three-dimensional dam-foundation rock system finite element model is employed in analyses. The hydrodynamic interaction between reservoir water and dam-foundation system is implicitly taken into consideration by the Westergaard approach using surface finite elements added to dam-fluid and foundation-fluid interfaces. The concrete material model is used to present the cracking of dam concrete under a seismic load the using smeared crack approach based on the Willam and Warnke failure criterion. The materially nonlinear analysis for both dam concrete and foundation rock is performed using Drucker-Prager model. According to numerical results, tensile stresses and maximum strains reduce significantly in the materially nonlinear model. In addition, the cracking areas in the dam decrease also when material nonlinearity characteristics of the dam-foundation rock system is considered in analyses.","PeriodicalId":49980,"journal":{"name":"Journal of Theoretical and Applied Mechanics","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83113267","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, abnormal vibrations of 1 pump fluid in a crude oil efflux station in the Changqing Oilfield was investigated. Kinetic simulation was applied to flow fields in the crude oil efflux pump using Ansys to determine trends of the impeller static pressure, speed, total pressure, wall pressure of the impeller, outlet pressure and pressure on the pump shell and to identify the reasons behind the abnormal vibrations. The results indicated that the axial vibration amplitude of the pump could be reduced from 1.3 mm down to 0.68mm if the operation parameters of the external control oil pump were set as 2500-2550r/min and 325-335m 3 /h, respectively.
{"title":"Analysis of abnormal vibrations of crude oil efflux pumps using Ansys","authors":"Tianqi Wang, Linfu Xie, Hongsheng Yu, Xiuliang Wei, Pengmin Dong, Tianyi Zhao","doi":"10.15632/jtam-pl/157464","DOIUrl":"https://doi.org/10.15632/jtam-pl/157464","url":null,"abstract":"In this study, abnormal vibrations of 1 pump fluid in a crude oil efflux station in the Changqing Oilfield was investigated. Kinetic simulation was applied to flow fields in the crude oil efflux pump using Ansys to determine trends of the impeller static pressure, speed, total pressure, wall pressure of the impeller, outlet pressure and pressure on the pump shell and to identify the reasons behind the abnormal vibrations. The results indicated that the axial vibration amplitude of the pump could be reduced from 1.3 mm down to 0.68mm if the operation parameters of the external control oil pump were set as 2500-2550r/min and 325-335m 3 /h, respectively.","PeriodicalId":49980,"journal":{"name":"Journal of Theoretical and Applied Mechanics","volume":"56 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82888218","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}
G. Ilewicz, J. Mrozowski, J. Awrejcewicz, B. Zagrodny, M. Ludwicki
The main aim of the article is to define a criterion of dynamic stability based on the Flash-Hogan principle and the ZMP method. The gait researches were focused on analysis and observation of the human biomechanism with the optical system Optitrack. The smooth reference trajectory is defined forming a stability pattern. The optimal, due to the minimum jerk criterion, ZMP trajectory is illustrated in the results Section in order to demonstrate the dynamic stability pattern for the needs of rehabilitation in cases of neuromuscular damage or injuries affecting gait stability.
{"title":"Biomechanical criterion of dynamic stability based on ZMP formula and Flash-Hogan principle of minimum jerk","authors":"G. Ilewicz, J. Mrozowski, J. Awrejcewicz, B. Zagrodny, M. Ludwicki","doi":"10.15632/jtam-pl/157011","DOIUrl":"https://doi.org/10.15632/jtam-pl/157011","url":null,"abstract":"The main aim of the article is to define a criterion of dynamic stability based on the Flash-Hogan principle and the ZMP method. The gait researches were focused on analysis and observation of the human biomechanism with the optical system Optitrack. The smooth reference trajectory is defined forming a stability pattern. The optimal, due to the minimum jerk criterion, ZMP trajectory is illustrated in the results Section in order to demonstrate the dynamic stability pattern for the needs of rehabilitation in cases of neuromuscular damage or injuries affecting gait stability.","PeriodicalId":49980,"journal":{"name":"Journal of Theoretical and Applied Mechanics","volume":"15 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90159918","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}
Firstly, in this paper, based on the theory of the porous elastic medium and combined with the effective stress principle of unsaturated soil, a set of governing equations is established to describe consolidation of the unsaturated soil. Secondly, an analytical expression under any dynamic loads is obtained with the help of Laplace integral transformation. Finally, analysis of numerical examples under specific boundary conditions is made to discuss one-dimensional consolidation characteristics under harmonic loads and the influence of factors on the consolidation characteristics of unsaturated soil, such as excitation frequency and initial saturation.
{"title":"Analytical solution for one-dimensional consolidation of unsaturated soils under dynamic load","authors":"Zhi-yi Liu, Yu Song, Feng-xi Zhou, Li-ye Wang","doi":"10.15632/jtam-pl/157084","DOIUrl":"https://doi.org/10.15632/jtam-pl/157084","url":null,"abstract":"Firstly, in this paper, based on the theory of the porous elastic medium and combined with the effective stress principle of unsaturated soil, a set of governing equations is established to describe consolidation of the unsaturated soil. Secondly, an analytical expression under any dynamic loads is obtained with the help of Laplace integral transformation. Finally, analysis of numerical examples under specific boundary conditions is made to discuss one-dimensional consolidation characteristics under harmonic loads and the influence of factors on the consolidation characteristics of unsaturated soil, such as excitation frequency and initial saturation.","PeriodicalId":49980,"journal":{"name":"Journal of Theoretical and Applied Mechanics","volume":"11 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90673466","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. Kozma, Ana M. Girão Coelho, Junliang Yang, C. Odenbreit
This paper proposes a new concept and algorithm to transfer brittle and arbitrary load-slip curves into an effective shear resistance suitable for Eurocode 4. This algorithm is specifi-cally for demountable shear connections of composite beams which do not exhibit ductile behaviour as required in EC4. The algorithm is validated with numerical finite element models which have been calibrated against experimental results. The algorithm extends the scope of the code to cover demountable shear connections: it allows the EC4 (EN 1994-1-1) rules remain applicable for the evaluation of the plastic bending resistance of composite beams with partial shear connection.
本文提出了一种新的概念和算法，将脆性和任意荷载-滑移曲线转化为适用于欧洲规范4的有效抗剪系数。该算法是专门针对组合梁的可拆卸剪切连接，不表现出EC4所要求的延性行为。用数值有限元模型对算法进行了验证，并与实验结果进行了校正。该算法扩展了规范的范围，涵盖了可拆卸的剪切连接:它允许EC4 (EN 1994-1-1)规则仍然适用于评估具有部分剪切连接的组合梁的塑性抗弯性能。
{"title":"A new concept and algorithm to transfer brittle and arbitrary load-slip curves into an effective shear resistance suitable for Eurocode 4","authors":"A. Kozma, Ana M. Girão Coelho, Junliang Yang, C. Odenbreit","doi":"10.15632/jtam-pl/156164","DOIUrl":"https://doi.org/10.15632/jtam-pl/156164","url":null,"abstract":"This paper proposes a new concept and algorithm to transfer brittle and arbitrary load-slip curves into an effective shear resistance suitable for Eurocode 4. This algorithm is specifi-cally for demountable shear connections of composite beams which do not exhibit ductile behaviour as required in EC4. The algorithm is validated with numerical finite element models which have been calibrated against experimental results. The algorithm extends the scope of the code to cover demountable shear connections: it allows the EC4 (EN 1994-1-1) rules remain applicable for the evaluation of the plastic bending resistance of composite beams with partial shear connection.","PeriodicalId":49980,"journal":{"name":"Journal of Theoretical and Applied Mechanics","volume":"4 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84884570","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}
For unconventional oil and gas reservoirs such as shale oil and gas as well as tight oil and gas, hydraulic fracturing generally enhances oil recovery. However, the flowback rate of the residual fracturing fluid is low. The residual fracturing fluid in the fracture or the rock matrix can reduce relative permeability of oil and gas, and the production rate will decrease. Therefore, it is necessary to study the factors that affect the flowback rate of the fracturing fluid. Most previous studies used the slot model, and viscous and capillary forces explain stable discharge in porous media. The conclusions were only a primarily qualitative analysis. The factors from experimental studies were not comprehensive, and they did not consider the influence of gravity. There are few studies on unstable drainage in porous media under different displacement directions. This paper presents a carboxymethyl hydroxypropyl guar gum fracturing fluid with good temperature resistance, and a fracturing fluid flowback experiment is carried on. The effects of the displacement direction, injection pressure, interfacial tension, fracturing fluid viscosity, and proppant wettability on the flowback rate are analyzed. The research results can provide formulation of the on-site construction scheme.
{"title":"Experimental study on the flowback of a carboxymethyl hydroxypropyl guar gum fracturing fluid with good temperature resistance","authors":"X. Dai, Lei Li, Xin Zhang, Z. Cheng","doi":"10.15632/jtam-pl/155988","DOIUrl":"https://doi.org/10.15632/jtam-pl/155988","url":null,"abstract":"For unconventional oil and gas reservoirs such as shale oil and gas as well as tight oil and gas, hydraulic fracturing generally enhances oil recovery. However, the flowback rate of the residual fracturing fluid is low. The residual fracturing fluid in the fracture or the rock matrix can reduce relative permeability of oil and gas, and the production rate will decrease. Therefore, it is necessary to study the factors that affect the flowback rate of the fracturing fluid. Most previous studies used the slot model, and viscous and capillary forces explain stable discharge in porous media. The conclusions were only a primarily qualitative analysis. The factors from experimental studies were not comprehensive, and they did not consider the influence of gravity. There are few studies on unstable drainage in porous media under different displacement directions. This paper presents a carboxymethyl hydroxypropyl guar gum fracturing fluid with good temperature resistance, and a fracturing fluid flowback experiment is carried on. The effects of the displacement direction, injection pressure, interfacial tension, fracturing fluid viscosity, and proppant wettability on the flowback rate are analyzed. The research results can provide formulation of the on-site construction scheme.","PeriodicalId":49980,"journal":{"name":"Journal of Theoretical and Applied Mechanics","volume":"89 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85784689","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}
C. Yu, Zhili Zhang, Ning‐Ning Wang, Xutao Nie, Qiang Peng, Zhenhua Chen
The wind tunnel with variable Mach numbers controlled by a single jack is highly desired in the aerospace, automobile and building industry due to its superior controllability and working range. Decreasing the temperature of a test gas is an efficient and economical approach to achieving higher Reynolds numbers that accommodate all working statuses of test subjects, which however, brings new challenges to the wind tunnel design nowadays. This paper proposes a new design concept of a single-jack variable Mach number nozzle based on its particular cryogenic characteristics, as the nozzle is the core structure to achieve variable Mach numbers. The contours of the nozzle under different Reynolds numbers and Mach numbers are modeled and solved by an incomplete elliptic integral, followed by modification with cryogenic characteristics. A 0.3-m cryogenic wind tunnel is utilized as a validation platform for the nozzle design, resulting in designed contours being in line with the measured contours. Moreover, the root means square (RMS) deviations of Mach number 1.3 at the core position are controlled within 0.011 in low and high temperatures, which surpasses the other existing wind tunnels.
{"title":"Design and validation of a single-jack variable Mach number nozzle in a cryogenic transonic wind tunnel","authors":"C. Yu, Zhili Zhang, Ning‐Ning Wang, Xutao Nie, Qiang Peng, Zhenhua Chen","doi":"10.15632/jtam-pl/155983","DOIUrl":"https://doi.org/10.15632/jtam-pl/155983","url":null,"abstract":"The wind tunnel with variable Mach numbers controlled by a single jack is highly desired in the aerospace, automobile and building industry due to its superior controllability and working range. Decreasing the temperature of a test gas is an efficient and economical approach to achieving higher Reynolds numbers that accommodate all working statuses of test subjects, which however, brings new challenges to the wind tunnel design nowadays. This paper proposes a new design concept of a single-jack variable Mach number nozzle based on its particular cryogenic characteristics, as the nozzle is the core structure to achieve variable Mach numbers. The contours of the nozzle under different Reynolds numbers and Mach numbers are modeled and solved by an incomplete elliptic integral, followed by modification with cryogenic characteristics. A 0.3-m cryogenic wind tunnel is utilized as a validation platform for the nozzle design, resulting in designed contours being in line with the measured contours. Moreover, the root means square (RMS) deviations of Mach number 1.3 at the core position are controlled within 0.011 in low and high temperatures, which surpasses the other existing wind tunnels.","PeriodicalId":49980,"journal":{"name":"Journal of Theoretical and Applied Mechanics","volume":"40 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83688609","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 geometry dynamical modeling method for a double pendulum is explored with the Lie group and a double spherical space method. Four types of Lagrange equations are built for relative and absolute motion with the above two geometry methods, which are then used to explore the influence of different expressions for motion on the dynamic modeling and computations. With Legendre transformation, the Lagrange equations are transformed to Hamilton ones which are dynamical models greatly reduced. The models are solved by the same numerical method. The simulation results show that they are better for the relative group than for the absolute one in long time simulation with the same numerical computations. The Lie group based result is better than the double spherical space one.
{"title":"Comparison of long time simulation of Hamilton and Lagrange geometry dynamical models of a multibody system","authors":"Long Bai, X. Ge, L. Xia","doi":"10.15632/jtam-pl/156163","DOIUrl":"https://doi.org/10.15632/jtam-pl/156163","url":null,"abstract":"The geometry dynamical modeling method for a double pendulum is explored with the Lie group and a double spherical space method. Four types of Lagrange equations are built for relative and absolute motion with the above two geometry methods, which are then used to explore the influence of different expressions for motion on the dynamic modeling and computations. With Legendre transformation, the Lagrange equations are transformed to Hamilton ones which are dynamical models greatly reduced. The models are solved by the same numerical method. The simulation results show that they are better for the relative group than for the absolute one in long time simulation with the same numerical computations. The Lie group based result is better than the double spherical space one.","PeriodicalId":49980,"journal":{"name":"Journal of Theoretical and Applied Mechanics","volume":"228 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76096371","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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