Mechanics & Industry最新文献_第2页

Aeroelastic scaling of flying demonstrators: mode tracking technique 飞行演示的气动弹性尺度:模式跟踪技术

IF 1.2 4区工程技术

Mechanics & Industry Pub Date : 2022-01-01 DOI: 10.1051/meca/2021051

Joan Mas Colomer, N. Bartoli, T. Lefebvre, J. Morlier

引用次数: 1

An improved negative zero vibration anti-swing control strategy for grab ship unloader based on elastic wire rope model 基于弹性钢丝绳模型的抓斗卸船机改进负零振动防摆控制策略

IF 1.2 4区工程技术

Mechanics & Industry Pub Date : 2021-01-01 DOI: 10.1051/meca/2021045

Xiaohua Cao, Chao Meng, Yong Zhou, Meng Zhu

{"title":"An improved negative zero vibration anti-swing control strategy for grab ship unloader based on elastic wire rope model","authors":"Xiaohua Cao, Chao Meng, Yong Zhou, Meng Zhu","doi":"10.1051/meca/2021045","DOIUrl":"https://doi.org/10.1051/meca/2021045","url":null,"abstract":"A dynamic model of swing system of bridge-type ship unloader is established by considering the elastic factor of wire rope in this paper. Based on this model, an improved Negative Zero Vibration (NZV) shaper with optimal control parameters of variable rope length system is proposed to restrain the swing of grab. Then the control effects, influence of elasticity factor and parameter sensitivities are analyzed based on numerical simulation. The results show that the proposed control strategy can reduce the working cycle time of the grab ship unloader about 11% when considering the elastic factor of the wire rope, and the grab's maximum residual swing angle decreases by 67% when discharging at full load, and decreases by 79% when taking the cargos at empty load. This implies that the improved NZV control method provides better swing angle control performance and shorter operation time compared with the Zero Vibration (ZV) and Zero Vibration and Derivative (ZVD) methods. Moreover, elastic rope model can improve the swing angle control effect of grab based on the proposed control strategy compared with rigid rope model. The parameter sensitivity analysis displays that the grab's maximum residual swing angle by using the improved NZV method is sensitive to the change of the grab's center of gravity, and this angle is more sensitive to the wire rope diameter deviation compared with the elastic modulus deviation.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83639265","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}

引用次数: 4

Optimal design to control rotor shaft vibrations and thermal management on a supercritical CO2 microturbine 超临界CO2微涡轮转子轴振动控制与热管理优化设计

IF 1.2 4区工程技术

Mechanics & Industry Pub Date : 2021-01-01 DOI: 10.1051/MECA/2021023

Jun Yu Li, H. Gurgenci, Jishun Li, Lun Li, Z. Guan, Fang Yang

{"title":"Optimal design to control rotor shaft vibrations and thermal management on a supercritical CO2 microturbine","authors":"Jun Yu Li, H. Gurgenci, Jishun Li, Lun Li, Z. Guan, Fang Yang","doi":"10.1051/MECA/2021023","DOIUrl":"https://doi.org/10.1051/MECA/2021023","url":null,"abstract":"Supercritical carbon dioxide (SCO2) Brayton cycle microturbine can be used for the next generation of solar power. In order to comprehensively optimize the supporting system and cooling device parameters of Brayton cycle shafting, the concept of chaos interval is introduced by chaotic mapping, and the CIMPSO algorithm is proposed to optimize the multi-objective rotor system model with nonlinear variables.The results show that the resonance amplitude of the optimized model is effectively attenuated, and the critical speed point is far away from the working speed, which shows the robustness of the optimization algorithm. Finally, based on arbitrary several sets of optimization solutions and empirical parameters, the finite element model of shafting is established for simulation, and the results show that the optimized solution has certain guiding significance for the design of the rotor system.The cooling device is designed and simulated by CFD method based on the optimal solution set. Both the inlet boundary conditions of given pressure (1 MPα) and given mass flow rate (0.1 kg/s) numerical calculations were carried out to characterize the cooling performance, for different jet impingement configurations (Hr/din = 0.0125 ∼ 5).Several sets of analyses show the strong effects of the jet-to-target spacing (Hr/din) on the rotor thermal performance at a given diameter (din) of the nozzle. Average temperature (Tc) at the free end of the rotor show that, as jet-to-target distance decreases (0.0125 ≤ Hr/din ≤ 0.33), the heat dissipation efficiency of the cooling device with the given pressure boundary condition tends to decrease, while the conclusion is opposite when the inlet boundary condition is set to the given mass flow rate. And there is an interval for the optimal combination (Hr/din) to promote the cooling efficiency.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78429237","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}

引用次数: 3

On the way to fault detection method in moving load dynamics problem by modified recurrent neural networks approach 基于改进递归神经网络的移动负荷动力学故障检测方法研究

IF 1.2 4区工程技术

Mechanics & Industry Pub Date : 2021-01-01 DOI: 10.1051/MECA/2021009

S. Jena, D. Parhi

{"title":"On the way to fault detection method in moving load dynamics problem by modified recurrent neural networks approach","authors":"S. Jena, D. Parhi","doi":"10.1051/MECA/2021009","DOIUrl":"https://doi.org/10.1051/MECA/2021009","url":null,"abstract":"Parameters identification on structure subjected to moving load can be predicted by using the accurate and reliable data. The concepts of recurrent neural networks (RNNs) approach have been used in parameters (crack locations and severities) identifications in structure subjected to moving load in the present methodology. This methodology has incorporated the knowledge based Elman's recurrent neural networks (ERNNs) and Jordan's recurrent neural networks (JRNNs) jointly for the identification of parameters. This approach has been addressed as the inverse problem for predicting the locations and quantification of cracks in the structure in a supervised manner. The Levenberg-Marquardt's back propagation algorithm is implemented to train the proposed networks. To check the robustness of the present method, Numerical studies followed by Finite Element Analysis (FEA) and experimental verifications (Forward problems) are presented as a case study by considering a multi-cracked simply supported structure under a moving mass. The estimated crack locations and severities obtained from the proposed RNNs model converge well with those of FEA and experiments. From the demonstration of the case study, it concludes that the proposed analogy can identify and quantify the crack locations and severities effectively.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73350812","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}

引用次数: 2

High load capacity spur gears with conchoidal path of contact 具有高负载能力的圆锥形接触路径直齿齿轮

IF 1.2 4区工程技术

Mechanics & Industry Pub Date : 2021-01-01 DOI: 10.1051/meca/2021044

P. Tkach, P. Nosko, O. Bashta, Yurii Tsybrii, Oleksii Nosko

引用次数: 0

Analysis of longitudinal vibration acceleration based on continuous time-varying model of high-speed elevator lifting system with random parameters 基于随机参数高速电梯提升系统连续时变模型的纵向振动加速度分析

IF 1.2 4区工程技术

Mechanics & Industry Pub Date : 2021-01-01 DOI: 10.1051/MECA/2021027

Qing Zhang, Hou Tao, Haowen Jing, Ruijun Zhang

{"title":"Analysis of longitudinal vibration acceleration based on continuous time-varying model of high-speed elevator lifting system with random parameters","authors":"Qing Zhang, Hou Tao, Haowen Jing, Ruijun Zhang","doi":"10.1051/MECA/2021027","DOIUrl":"https://doi.org/10.1051/MECA/2021027","url":null,"abstract":"In this paper, for studying the influence of the randomness of structural parameters of high-speed elevator lifting system (HELS) caused by manufacturing error and installation error, a continuous time-varying model of HELS was constructed, considering the compensation rope mass and the tension of the tensioning system. The Galerkin weighted residual method is employed to transform the partial differential equation with infinite degrees of freedom (DOF) into the ordinary differential equation. The five-order polynomial is used to fit the actual operation state curve of elevator, and input as operation parameters. The precise integration method of time-varying model of HELS is proposed. The determination part and the random part response expression of the longitudinal dynamic response of HELS are derived by the random perturbation method. Using the precise integration method, the sensitivity of random parameters is determined by solving the random part response expression of time-varying model of HELS, and the digital characteristics of the acceleration response are analyzed. It is found that the line density of the hoisting wire rope has the maximum sensitivity on longitudinal vibration velocity response, displacement response and acceleration response, and the sensitivity of the elastic modulus of the wire rope is smallest.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82191096","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}

引用次数: 4

Wheel slip ratio regulation for investigating the vehicle's dynamic behavior during braking and steering input 用于研究车辆在制动和转向输入时的动态行为的轮滑比调节

IF 1.2 4区工程技术

Mechanics & Industry Pub Date : 2021-01-01 DOI: 10.1051/MECA/2021016

A. Shahabi, A. H. Kazemian, S. Farahat, F. Sarhaddi

{"title":"Wheel slip ratio regulation for investigating the vehicle's dynamic behavior during braking and steering input","authors":"A. Shahabi, A. H. Kazemian, S. Farahat, F. Sarhaddi","doi":"10.1051/MECA/2021016","DOIUrl":"https://doi.org/10.1051/MECA/2021016","url":null,"abstract":"In this study, the vehicle's dynamic behavior during braking and steering input is investigated by considering the quarter-car model. The case study for this research is a Sport-Utility Vehicle (SUV) with the anti-lock braking system (ABS) and nonlinear dynamic equations are considered for it along with Pacejka tire model. Regulating the wheel slip ratio in the optimal value for different conditions of the road surface (dry, wet and icy) during braking is considered as the ABS control strategy. In order to regulating the wheel slip ratio in the optimal value, an intelligent adaptive fuzzy controller that can perform online parameter estimation is considered. In this regard, the proposed controller tracks the optimal wheel slip ratio with changing the condition of the road surface from dry to wet and icy. The adaptive fuzzy controller consists of linguistic base, inference engine and defuzzifier section. The wheel slip ratio and vehicle longitudinal acceleration are selected as inputs of the controller, controller adapter and detector of the road surface condition. During braking and steering input, effective parameters of the wheel that are affected on the vehicle's dynamic behavior and its stability are investigated.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89577177","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}

引用次数: 2

Effect of ambient temperature on the formation mechanism of PTFE liner transfer film of spherical plain bearings 环境温度对球面滑动轴承PTFE衬垫传递膜形成机理的影响

IF 1.2 4区工程技术

Mechanics & Industry Pub Date : 2021-01-01 DOI: 10.1051/MECA/2021007

M. Qiu, K. Tian, Yatao Zhang

{"title":"Effect of ambient temperature on the formation mechanism of PTFE liner transfer film of spherical plain bearings","authors":"M. Qiu, K. Tian, Yatao Zhang","doi":"10.1051/MECA/2021007","DOIUrl":"https://doi.org/10.1051/MECA/2021007","url":null,"abstract":"The relationship between the formation of the transfer film and the tribological properties of the self-lubricating spherical plain bearing was studied at the ambient temperature of 25–145 °C. The results show that the wear, friction coefficient and friction temperature increase of the spherical plain bearings all decreased first and then increased with the increase of the ambient temperature. The general trend is that the bearing has the most excellent anti-friction and wear resistance at 55–85 °C. An increase in ambient temperature will accelerate the formation speed of PTFE transfer film and shorten the running-in period of the bearing, but the ambient temperature above 85 °C will shorten the duration of the PTFE transfer film, thus accelerating the bearing into the degradation period. The transfer film coverage of the liner after wear was characterized, and it was found that the transfer film coverage was the largest when the ambient temperature was 85 °C. The wear form of the bearing is mainly abrasive wear and adhesive wear, and the aramid fiber is more prone to adhesive wear. The anti-friction effect of the bearing is determined by the PTFE transfer film. Elevated ambient temperature can promote the formation of PTFE transfer film and enhance the antifriction effect, but if the ambient temperature is too high, the wear resistance of the PTFE transfer film will be reduced, thus reducing the friction reduction effect.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90204230","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}

引用次数: 4

Model characterization and mechanical property analysis of bimetallic functionally graded turbine discs 双金属功能梯度涡轮盘的模型表征及力学性能分析

IF 1.2 4区工程技术

Mechanics & Industry Pub Date : 2021-01-01 DOI: 10.1051/MECA/2021001

Yiwei Dong, Weiguo Yan, T. Liao, Qianwen Ye, Y. You

{"title":"Model characterization and mechanical property analysis of bimetallic functionally graded turbine discs","authors":"Yiwei Dong, Weiguo Yan, T. Liao, Qianwen Ye, Y. You","doi":"10.1051/MECA/2021001","DOIUrl":"https://doi.org/10.1051/MECA/2021001","url":null,"abstract":"In advanced propulsive systems, a turbine disc bears vast mechanical and thermal loads under its working conditions of high-temperature gradients and high rotational velocity.The complex working conditions of aero-engine turbine discs place stringent performance requirements on the materials used. With dual organizations and superior composite performances, bimetallic functionally graded turbine discs have become a focus in the research of high thrust-to-weight ratio aero-engines. To study the mechanical properties of new bimetallic functionally graded materials under service conditions, we propose a volumetric fraction expression and adjustable composition distribution parameters that are suitable for simulating the composition distribution of bimetallic functionally graded turbine discs. On this basis, a characterization model for functionally graded materials based on the analysis of the internal thermodynamic properties of bimetallic turbine discs is established. The thermodynamic properties and fatigue performances of functionally graded materials under service conditions are analysed. Mechanical property simulations of functionally graded turbine discs are performed using different composition distribution parameters, and reasonable ranges are determined for the various composition distribution parameters. The results show that bimetallic functionally graded turbine discs are suitable for high-stress-gradient and high-temperature-gradient environments with lower weights than those of current GH4169 alloy turbine discs.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84962308","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}

引用次数: 1

Effects of molecule force on free vibration for a micro electromagnetic harmonic drive system 分子力对微电磁谐波驱动系统自由振动的影响

IF 1.2 4区工程技术

Mechanics & Industry Pub Date : 2021-01-01 DOI: 10.1051/MECA/2021008

Dan Zhao, Lizhong Xu, Yuming Fu

引用次数: 2