首页 > 最新文献

Mechanika最新文献

英文 中文
Study on Mechanical Behavior and Deformation Law of Expansion Pro-cess of Expansion Screen Base Pipe 膨胀筛基管膨胀过程力学行为及变形规律研究
4区 工程技术 Q4 Physics and Astronomy Pub Date : 2023-10-18 DOI: 10.5755/j02.mech.33414
Pu LIU, Zhengqiang TANG, Ning DAI, Quanlin XIAO, Zhiping WANG, Chenlong WANG
The expansion process of the base pipe of the expanded screen pipe includes large displacement elastic-plastic deformation problems such as geometric nonlinearity, material nonlinearity and contact nonlinearity. In this paper, based on the elastic-plastic deformation mechanism of the base pipe of expanded screen pipe, finite element equations are established and numerical simulation is used to construct a finite element simulation model to study the mechanical behavior and deformation law of Φ203.2 mm base pipe of the expanded screen pipe expansion process. The results show that the expansion rate has no effect on the increase of wall thickness, and the decrease is proportional to the expansion rate. The greater the expansion rate, the greater the residual stress at both ends of the slot.
膨胀筛管基管的膨胀过程包含几何非线性、材料非线性和接触非线性等大位移弹塑性变形问题。本文基于膨胀筛管基管弹塑性变形机理,建立有限元方程,采用数值模拟方法构建有限元仿真模型,研究膨胀筛管膨胀过程中Φ203.2 mm基管的力学行为及变形规律。结果表明:膨胀率对壁厚的增加没有影响,壁厚的减小与膨胀率成正比;膨胀率越大,槽两端的残余应力越大。
{"title":"Study on Mechanical Behavior and Deformation Law of Expansion Pro-cess of Expansion Screen Base Pipe","authors":"Pu LIU, Zhengqiang TANG, Ning DAI, Quanlin XIAO, Zhiping WANG, Chenlong WANG","doi":"10.5755/j02.mech.33414","DOIUrl":"https://doi.org/10.5755/j02.mech.33414","url":null,"abstract":"The expansion process of the base pipe of the expanded screen pipe includes large displacement elastic-plastic deformation problems such as geometric nonlinearity, material nonlinearity and contact nonlinearity. In this paper, based on the elastic-plastic deformation mechanism of the base pipe of expanded screen pipe, finite element equations are established and numerical simulation is used to construct a finite element simulation model to study the mechanical behavior and deformation law of Φ203.2 mm base pipe of the expanded screen pipe expansion process. The results show that the expansion rate has no effect on the increase of wall thickness, and the decrease is proportional to the expansion rate. The greater the expansion rate, the greater the residual stress at both ends of the slot.","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135885031","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: 0
Transfemoral Prostheses: Importance of Proper Fitting and Materials for Socket 3D-Printing 经股假体:正确的配件和材料对3d打印窝的重要性
4区 工程技术 Q4 Physics and Astronomy Pub Date : 2023-10-18 DOI: 10.5755/j02.mech.33957
Donatas DAUBLYS, Aurelijus DOMEIKA, Birutė SINKUTĖ
Lower limb prostheses can replace missing parts of the body and improve a patient's quality of life. The individual design and manufacture of a prosthesis is particularly beneficial for the wearer. The 3D printing technique can be used to make prosthesis sockets from recycled polyamide powder (PA2200), but the mechanical properties of these printed materials have not been studied in detail. Tensile and bending tests were performed, and the results obtained did not show statistically significant differences between these materials. An improperly fitted prosthesis affects the biomechanics of gait. Posture and gait analysis of a person wearing a prosthesis was performed using the “Qualisys”, "AMTI" force plates, and “Zebris” systems, and the results showed differences between the prosthetic and the healthy leg.
下肢假肢可以代替身体缺失的部分,提高病人的生活质量。假肢的个性化设计和制造对佩戴者尤其有益。3D打印技术可用于用回收聚酰胺粉末(PA2200)制作假体插座,但这些打印材料的机械性能尚未得到详细研究。进行了拉伸和弯曲测试,获得的结果在这些材料之间没有统计学上的显着差异。不合适的假肢会影响步态的生物力学。使用“Qualisys”、“AMTI”力板和“Zebris”系统对佩戴义肢的人进行姿势和步态分析,结果显示义肢与健康腿之间存在差异。
{"title":"Transfemoral Prostheses: Importance of Proper Fitting and Materials for Socket 3D-Printing","authors":"Donatas DAUBLYS, Aurelijus DOMEIKA, Birutė SINKUTĖ","doi":"10.5755/j02.mech.33957","DOIUrl":"https://doi.org/10.5755/j02.mech.33957","url":null,"abstract":"Lower limb prostheses can replace missing parts of the body and improve a patient's quality of life. The individual design and manufacture of a prosthesis is particularly beneficial for the wearer. The 3D printing technique can be used to make prosthesis sockets from recycled polyamide powder (PA2200), but the mechanical properties of these printed materials have not been studied in detail. Tensile and bending tests were performed, and the results obtained did not show statistically significant differences between these materials. An improperly fitted prosthesis affects the biomechanics of gait. Posture and gait analysis of a person wearing a prosthesis was performed using the “Qualisys”, \"AMTI\" force plates, and “Zebris” systems, and the results showed differences between the prosthetic and the healthy leg.","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135885161","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: 0
Zero Point Compensation Control of the Proportional Valve with Negative Overlap 负重叠比例阀的零点补偿控制
IF 0.7 4区 工程技术 Q4 Physics and Astronomy Pub Date : 2023-08-09 DOI: 10.5755/j02.mech.29715
Le Zeng, Hongzhang Li, J. Tan, Jun Yang
In order to improve the performance of the negative overlapped valve controlled asymmetrical cylinder system, a theoretical zero point model of the valve with symmetric and unequal negative overlap was established. The simulation results showed that the zero point of the system will shift as the load changes, and the error of the theoretical zero point is relatively larger in some certain pressure states. In order to find the zero point quickly and steadily and improve the positioning accuracy of the system, a zero point compensation controller based on theoretical zero point plus error integral control was designed. Compared the pure P controller with the compound control of P controller and zero point compensation controller, the control accuracy of the system has been greatly improved under transient load and sinusoidal load interference.
为了提高负重叠阀控非对称缸系统的性能,建立了对称和不对称负重叠阀控非对称缸系统的理论零点模型。仿真结果表明,系统零点会随着载荷的变化而发生位移,在某些压力状态下理论零点误差较大。为了快速稳定地找到零点,提高系统的定位精度,设计了基于理论零点加误差积分控制的零点补偿控制器。与纯P控制器和P控制器与零点补偿控制器的复合控制相比,在瞬态负载和正弦负载干扰下,系统的控制精度得到了很大的提高。
{"title":"Zero Point Compensation Control of the Proportional Valve with Negative Overlap","authors":"Le Zeng, Hongzhang Li, J. Tan, Jun Yang","doi":"10.5755/j02.mech.29715","DOIUrl":"https://doi.org/10.5755/j02.mech.29715","url":null,"abstract":"In order to improve the performance of the negative overlapped valve controlled asymmetrical cylinder system, a theoretical zero point model of the valve with symmetric and unequal negative overlap was established. The simulation results showed that the zero point of the system will shift as the load changes, and the error of the theoretical zero point is relatively larger in some certain pressure states. In order to find the zero point quickly and steadily and improve the positioning accuracy of the system, a zero point compensation controller based on theoretical zero point plus error integral control was designed. Compared the pure P controller with the compound control of P controller and zero point compensation controller, the control accuracy of the system has been greatly improved under transient load and sinusoidal load interference.","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47926962","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: 0
Lubrication analysis of hydrodynamic-static hybrid bearing with deep-shallow chambers considering thermal conduction 考虑热传导的深浅腔动静压混合轴承润滑分析
IF 0.7 4区 工程技术 Q4 Physics and Astronomy Pub Date : 2023-08-09 DOI: 10.5755/j02.mech.33196
Qianwen Huang, Zeyu Zhao, Huai-Zhen Liu
The oil film separates the shaft-bearing system to reduce the frictional force of contact surfaces with large temperature variations owing to thermal conduction. Multiple impact factors seriously affected the lubrication behavior of the bearing during actual working process. An applicable model regarding the lubrication analysis of a hydrodynamic-static hybrid bearing with deep-shallow chambers is proposed and validated with published literature. The lubrication behavior includes film pressure, load capacity, bearing stiffness and flow rate is numerically calculated with centered finite difference method by solving the Reynolds equation. The influence of film thickness and working temperature are considered, over a range of eccentricity ratio. Moreover, the temperature variation caused by thermal conduction is analyzed in details. To investigate the influence of thermal conduction on the lubrication behavior, the results show that the load capacity, bearing stiffness, friction power, and flow power significantly decline with the consideration of thermal conduction. This study proposes an accurate model that is helpful for the design of hydrodynamic-static hybrid bearings with deep-shallow chambers under low rotational speed, heavy load, and high temperature conditions.
油膜分离轴-轴承系统,以减少由于热传导而产生的大温度变化接触面的摩擦力。在实际工作过程中,多种影响因素严重影响了轴承的润滑性能。提出了一种适用于深浅腔动静压混合轴承润滑分析的模型,并用已发表的文献进行了验证。通过求解雷诺方程,采用中心有限差分法对膜压力、承载能力、承载刚度和流量等润滑特性进行了数值计算。在一定的偏心比范围内,考虑了膜厚和工作温度的影响。此外,还详细分析了热传导引起的温度变化。为了研究热传导对润滑性能的影响,结果表明:考虑热传导后,承载能力、承载刚度、摩擦功率和流动功率显著下降。该研究为低转速、重载、高温工况下深浅腔动静压混合轴承的设计提供了准确的模型。
{"title":"Lubrication analysis of hydrodynamic-static hybrid bearing with deep-shallow chambers considering thermal conduction","authors":"Qianwen Huang, Zeyu Zhao, Huai-Zhen Liu","doi":"10.5755/j02.mech.33196","DOIUrl":"https://doi.org/10.5755/j02.mech.33196","url":null,"abstract":"The oil film separates the shaft-bearing system to reduce the frictional force of contact surfaces with large temperature variations owing to thermal conduction. Multiple impact factors seriously affected the lubrication behavior of the bearing during actual working process. An applicable model regarding the lubrication analysis of a hydrodynamic-static hybrid bearing with deep-shallow chambers is proposed and validated with published literature. The lubrication behavior includes film pressure, load capacity, bearing stiffness and flow rate is numerically calculated with centered finite difference method by solving the Reynolds equation. The influence of film thickness and working temperature are considered, over a range of eccentricity ratio. Moreover, the temperature variation caused by thermal conduction is analyzed in details. To investigate the influence of thermal conduction on the lubrication behavior, the results show that the load capacity, bearing stiffness, friction power, and flow power significantly decline with the consideration of thermal conduction. This study proposes an accurate model that is helpful for the design of hydrodynamic-static hybrid bearings with deep-shallow chambers under low rotational speed, heavy load, and high temperature conditions.","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43245570","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: 0
Cluster-based Nonuniform Transformation Field Analysis of Gra-phene nanocomposites Graphene纳米复合材料的团簇非均匀变换场分析
IF 0.7 4区 工程技术 Q4 Physics and Astronomy Pub Date : 2023-08-09 DOI: 10.5755/j02.mech.33191
Yinan Jiang, Juanjuan Chen, L. Liang, Yangjian Xu, X. Ju
        Graphene nanocomposites have attracted much attention in materials science due to their superior me-chanical properties. It is difficult for conventional mul-tiscale methods to provide substantial assistance to the research of such materials due to their huge computa-tional costs. Nonuniform transformation field analysis is a very effective reduced order homogenization meth-od for elastoplastic multiscale analysis. However, the reduced order model derived from this method has the shortcoming of low universality and high application threshold. Therefore, an improved reduced order model is proposed by combining the nonuniform transfor-mation field analysis with the k-means clustering algo-rithm. One can embed the required microscopic consti-tutive model into the reduced order homogenization framework without the need to derive a new reduced order model. Based on the cluster-based nonuniform transformation field analysis, the influence of the mi-croscopic plastic strain field evolution on the macro-scopic response of the material under consideration is revealed, while the mechanical properties of graphene nanocomposites are predicted. The numerical results show that the new reduced order model can accurately predict the macroscopic mechanical properties of com-posite materials, and its acceleration rate compared to the traditional finite element computations reaches103-104 . Keywords:graphene nanocomposites; reduced order model; multiscale methods; clustering; nonuniform transfomation field analysis
石墨烯纳米复合材料以其优异的力学性能在材料科学领域引起了广泛的关注。传统的多尺度方法由于其巨大的计算成本,很难为此类材料的研究提供实质性的帮助。非均匀变换场分析是弹塑性多尺度分析中一种非常有效的降阶均匀化方法。然而,该方法导出的降阶模型存在通用性低、应用阈值高的缺点。因此,将非均匀变换场分析与k均值聚类算法相结合,提出了一种改进的降阶模型。可以将所需的微观组成模型嵌入到降阶均匀化框架中,而不需要导出新的降阶模型。基于基于簇的非均匀变换场分析,揭示了微观塑性应变场演化对所考虑材料宏观响应的影响,并预测了石墨烯纳米复合材料的力学性能。数值结果表明,新的降阶模型能够准确地预测复合材料的宏观力学性能,与传统的有限元计算相比,其加速率达到103-104。关键词:石墨烯纳米复合材料;降阶模型;多尺度方法;聚类;非均匀变换场分析
{"title":"Cluster-based Nonuniform Transformation Field Analysis of Gra-phene nanocomposites","authors":"Yinan Jiang, Juanjuan Chen, L. Liang, Yangjian Xu, X. Ju","doi":"10.5755/j02.mech.33191","DOIUrl":"https://doi.org/10.5755/j02.mech.33191","url":null,"abstract":"        Graphene nanocomposites have attracted much attention in materials science due to their superior me-chanical properties. It is difficult for conventional mul-tiscale methods to provide substantial assistance to the research of such materials due to their huge computa-tional costs. Nonuniform transformation field analysis is a very effective reduced order homogenization meth-od for elastoplastic multiscale analysis. However, the reduced order model derived from this method has the shortcoming of low universality and high application threshold. Therefore, an improved reduced order model is proposed by combining the nonuniform transfor-mation field analysis with the k-means clustering algo-rithm. One can embed the required microscopic consti-tutive model into the reduced order homogenization framework without the need to derive a new reduced order model. Based on the cluster-based nonuniform transformation field analysis, the influence of the mi-croscopic plastic strain field evolution on the macro-scopic response of the material under consideration is revealed, while the mechanical properties of graphene nanocomposites are predicted. The numerical results show that the new reduced order model can accurately predict the macroscopic mechanical properties of com-posite materials, and its acceleration rate compared to the traditional finite element computations reaches103-104 . \u0000Keywords:graphene nanocomposites; reduced order model; multiscale methods; clustering; nonuniform transfomation field analysis","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49670219","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: 0
Novel Meshing Stiffness Model for Spur Gear Pairs considering the Temperature Effect 考虑温度效应的正齿轮副啮合刚度模型
IF 0.7 4区 工程技术 Q4 Physics and Astronomy Pub Date : 2023-08-09 DOI: 10.5755/j02.mech.33776
Y. He, Haibo Yang
This work studied the effect of temperature on gear stiffness in the full temperature range which contained thermal expansion and cold shrinkage. Considering the temperature effect, a meshing stiffness model for spur gear pairs in the full temperature range was established based on the conservation of energy. The general calculation formula for the gear pair’s temperature meshing stiffness in the full temperature range was derived. The influence of addendum modification and gear temperature distribution on gear stiffness was studied. Thereafter, the proposed model was verified experimentally. The results revealed that the temperature stiffness was smaller than the standard stiffness of the gears in the full temperature range. When the temperature of the gears increased from an initial temperature, which was lower than the standard temperature, the temperature stiffness of the gear first increased and then decreased. Moreover, the obtained results could provide theoretical support for an accurate dynamic analysis of gear transmission systems in the full temperature range.
在包含热膨胀和冷缩的全温度范围内,研究了温度对齿轮刚度的影响。考虑温度效应,建立了基于能量守恒的全温度范围内直齿轮副啮合刚度模型。推导了全温度范围内齿轮副温度啮合刚度的一般计算公式。研究了齿顶修形和齿轮温度分布对齿轮刚度的影响。随后,对该模型进行了实验验证。结果表明,在整个温度范围内,齿轮的温度刚度小于标准刚度。当齿轮温度从低于标准温度的初始温度开始升高时,齿轮的温度刚度先增大后减小。所得结果可为齿轮传动系统在全温度范围内的精确动力学分析提供理论支持。
{"title":"Novel Meshing Stiffness Model for Spur Gear Pairs considering the Temperature Effect","authors":"Y. He, Haibo Yang","doi":"10.5755/j02.mech.33776","DOIUrl":"https://doi.org/10.5755/j02.mech.33776","url":null,"abstract":"This work studied the effect of temperature on gear stiffness in the full temperature range which contained thermal expansion and cold shrinkage. Considering the temperature effect, a meshing stiffness model for spur gear pairs in the full temperature range was established based on the conservation of energy. The general calculation formula for the gear pair’s temperature meshing stiffness in the full temperature range was derived. The influence of addendum modification and gear temperature distribution on gear stiffness was studied. Thereafter, the proposed model was verified experimentally. The results revealed that the temperature stiffness was smaller than the standard stiffness of the gears in the full temperature range. When the temperature of the gears increased from an initial temperature, which was lower than the standard temperature, the temperature stiffness of the gear first increased and then decreased. Moreover, the obtained results could provide theoretical support for an accurate dynamic analysis of gear transmission systems in the full temperature range.","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47732638","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: 0
Early Bearing Fault Detection Using EEMD and Three-Sigma Rule Denoising Method 基于EEMD和三σ规则去噪的轴承早期故障检测方法
IF 0.7 4区 工程技术 Q4 Physics and Astronomy Pub Date : 2023-08-09 DOI: 10.5755/j02.mech.32770
Yasser Damine, N. Bessous, A. C. Megherbi, S. Sbaa
Rotating electrical machines have several physical phenomena. Vibration is one of the important phenomena in the operation of rotating electrical machines. In addition, the vibration signal is considered an important source to have good information on the state of rotating electrical machinery. But this signal is rich in noise, especially under the presence of the bearing fault. This paper proposes a bearing fault diagnosis method based on EEMD and a denoising method based on three-sigma rule. In the first step, the EEMD decomposed the vibration signal into several components called Intrinsic Mode Functions (IMFs). After the calculation of the kurtosis of each IMF component, the signal is reconstructed by choosing components with higher values. To enhance periodic impulses, the three-sigma rule de-noising is applied to the reconstructed signal. As a final step, the envelope spectrum is used to determine the fault characteristic frequency. As a result of testing the bearing with inner race fault and the bearing with outer race, it was verified that the proposed approach suppressed noise effectively and extracted rich fault information from the vibration signals of bearings compared to the EEMD.
旋转电机有几种物理现象。振动是旋转电机运行中的重要现象之一。此外,振动信号被认为是了解旋转电机状态的重要信息来源。但该信号含有丰富的噪声,特别是在轴承故障存在的情况下。提出了一种基于EEMD的轴承故障诊断方法和一种基于三西格玛规则的去噪方法。在第一步中,EEMD将振动信号分解为称为内禀模态函数(IMFs)的几个分量。在计算每个IMF分量的峰度后,通过选择较高的分量重构信号。为了增强周期脉冲,对重构信号应用了3 σ规则去噪。最后,利用包络谱确定故障特征频率。通过对内圈故障轴承和外圈故障轴承的测试,验证了与EEMD相比,该方法有效地抑制了噪声,并从轴承振动信号中提取了丰富的故障信息。
{"title":"Early Bearing Fault Detection Using EEMD and Three-Sigma Rule Denoising Method","authors":"Yasser Damine, N. Bessous, A. C. Megherbi, S. Sbaa","doi":"10.5755/j02.mech.32770","DOIUrl":"https://doi.org/10.5755/j02.mech.32770","url":null,"abstract":"Rotating electrical machines have several physical phenomena. Vibration is one of the important phenomena in the operation of rotating electrical machines. In addition, the vibration signal is considered an important source to have good information on the state of rotating electrical machinery. But this signal is rich in noise, especially under the presence of the bearing fault. This paper proposes a bearing fault diagnosis method based on EEMD and a denoising method based on three-sigma rule. In the first step, the EEMD decomposed the vibration signal into several components called Intrinsic Mode Functions (IMFs). After the calculation of the kurtosis of each IMF component, the signal is reconstructed by choosing components with higher values. To enhance periodic impulses, the three-sigma rule de-noising is applied to the reconstructed signal. As a final step, the envelope spectrum is used to determine the fault characteristic frequency. As a result of testing the bearing with inner race fault and the bearing with outer race, it was verified that the proposed approach suppressed noise effectively and extracted rich fault information from the vibration signals of bearings compared to the EEMD.","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46274768","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: 0
A Battery-free Breathing monitoring System for post-COVID education 用于新冠肺炎后教育的无电池呼吸监测系统
IF 0.7 4区 工程技术 Q4 Physics and Astronomy Pub Date : 2023-08-09 DOI: 10.5755/j02.mech.33435
Jun Wu, Zhifang Fan
Embedded systems have more and more designs and applications in wearable health monitoring and the Internet of Things (IoT) recently. In this work, a battery-free human breathing monitoring system based on soft polyvinylidene fluoride (PVDF) piezoelectric thin film for pressure sensing and solid lead zirconate titanate (PZT) pads for powering energy harvest is designed and fabricated. Proper material and structure are chosen by the mechanical analysis to fabricate the systems. Then the device is used to measure the real breathing signal while studying (the memory test is used to represent the study procedure). The breathing frequency and intensity data are extracted and used in correction analysis with the testing score. And the results show that peaceful, slow, and deep breathing will have a positive influence on the testing score. This study opens the mind to combine the engineering designed device with education research, showing the broad application of mechanical and electronic systems.
嵌入式系统近年来在可穿戴健康监测和物联网(IoT)领域有越来越多的设计和应用。在这项工作中,设计并制造了一种基于用于压力传感的软聚偏氟乙烯(PVDF)压电薄膜和用于能量采集的固体锆钛酸铅(PZT)垫的无电池人体呼吸监测系统。通过力学分析选择合适的材料和结构来制造系统。然后,该设备用于在学习时测量真实的呼吸信号(记忆测试用于表示学习过程)。提取呼吸频率和强度数据,并将其与测试分数一起用于校正分析。结果表明,平静、缓慢和深呼吸会对测试成绩产生积极影响。这项研究打开了将工程设计的设备与教育研究相结合的大门,展示了机械和电子系统的广泛应用。
{"title":"A Battery-free Breathing monitoring System for post-COVID education","authors":"Jun Wu, Zhifang Fan","doi":"10.5755/j02.mech.33435","DOIUrl":"https://doi.org/10.5755/j02.mech.33435","url":null,"abstract":"Embedded systems have more and more designs and applications in wearable health monitoring and the Internet of Things (IoT) recently. In this work, a battery-free human breathing monitoring system based on soft polyvinylidene fluoride (PVDF) piezoelectric thin film for pressure sensing and solid lead zirconate titanate (PZT) pads for powering energy harvest is designed and fabricated. Proper material and structure are chosen by the mechanical analysis to fabricate the systems. Then the device is used to measure the real breathing signal while studying (the memory test is used to represent the study procedure). The breathing frequency and intensity data are extracted and used in correction analysis with the testing score. And the results show that peaceful, slow, and deep breathing will have a positive influence on the testing score. This study opens the mind to combine the engineering designed device with education research, showing the broad application of mechanical and electronic systems.","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49436055","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: 0
An Energy-Based Anti-Fatigue Optimization Design Method of Welded Rear Axle Housing in a Mining Dump Truck 矿用自卸车焊接后桥壳基于能量的抗疲劳优化设计方法
IF 0.7 4区 工程技术 Q4 Physics and Astronomy Pub Date : 2023-08-09 DOI: 10.5755/j02.mech.32371
Chen Mi, Yongqiang Li, Chen Zhang, Dong Zhang, Xianghuan Liu, Xiaolan Hu, Dejun Zhang
In order to improve the life expectancy of the rear axle housing in a mining dump truck, an energy-based anti-fatigue optimization design method was presented in this paper. The finite element model of rear axle housing was constructed and testified by the experimental data. The load history was obtained through multi-body dynamics analysis, and the multi-load step nonlinear finite element analysis was carried out to obtain the stress-strain response under different working conditions. The strain energy density method was used to evaluate the fatigue life of rear axle housing, and the results showed that its fatigue endurance was insufficient. Then, the lifetime of the most dangerous point was taken as the optimization objective, and the different plate thickness was considered as the design variables. The approximate model was constructed based on the response surface method, and the anti-fatigue optimization design was finally conducted on the bearing structure through the multi-island genetic algorithm. The minimum fatigue life of optimized rear axle housing was doubled.
为了提高矿用自卸车后桥壳的使用寿命,提出了一种基于能量的抗疲劳优化设计方法。建立了后桥壳的有限元模型,并用实验数据进行了验证。通过多体动力学分析获得载荷历程,并进行多载荷阶跃非线性有限元分析,获得不同工况下的应力-应变响应。采用应变能密度法对后桥壳的疲劳寿命进行了评价,结果表明后桥壳疲劳寿命不足。然后,以最危险点的寿命为优化目标,以不同板厚为设计变量。基于响应面法建立了近似模型,并通过多岛遗传算法对轴承结构进行了抗疲劳优化设计。优化后的后桥壳体的最小疲劳寿命增加了一倍。
{"title":"An Energy-Based Anti-Fatigue Optimization Design Method of Welded Rear Axle Housing in a Mining Dump Truck","authors":"Chen Mi, Yongqiang Li, Chen Zhang, Dong Zhang, Xianghuan Liu, Xiaolan Hu, Dejun Zhang","doi":"10.5755/j02.mech.32371","DOIUrl":"https://doi.org/10.5755/j02.mech.32371","url":null,"abstract":"In order to improve the life expectancy of the rear axle housing in a mining dump truck, an energy-based anti-fatigue optimization design method was presented in this paper. The finite element model of rear axle housing was constructed and testified by the experimental data. The load history was obtained through multi-body dynamics analysis, and the multi-load step nonlinear finite element analysis was carried out to obtain the stress-strain response under different working conditions. The strain energy density method was used to evaluate the fatigue life of rear axle housing, and the results showed that its fatigue endurance was insufficient. Then, the lifetime of the most dangerous point was taken as the optimization objective, and the different plate thickness was considered as the design variables. The approximate model was constructed based on the response surface method, and the anti-fatigue optimization design was finally conducted on the bearing structure through the multi-island genetic algorithm. The minimum fatigue life of optimized rear axle housing was doubled.","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43395818","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: 0
Study on the Influence of Synthesized Nano Ferrite Powder and Micron Ferrite Powder on Damping of a Single Degree of Freedom System 合成纳米铁氧体粉末和微米铁氧体粉末对单自由度系统阻尼影响的研究
IF 0.7 4区 工程技术 Q4 Physics and Astronomy Pub Date : 2023-08-09 DOI: 10.5755/j02.mech.32055
Easu Dakshnamoorthy, Siddharthan Arjunan, Amrutha Radhakrishnan, A. Gopal
Magneto Rheological Fluid (MRF) damper has been opted as a promising semi active element of advanced suspension system. This work focuses on the damping nature of magnetorheological fluid under the influence of a magnetic field strength, size and shape of the of the iron oxide particles. A reduced scale single degree of freedom quarter car model with two stage magnetorheological damper, viscosity measurement setup, synthesized and commercially available Fe2O3 powders are used for the experimental study. An air cooled electro-dynamic shaker, Data acquisition system, accelerometers and the Lab view software acquires and analyzes the response of the quarter car model. X-ray Diffraction and Scanning electron microscopy characterize the morphology of iron oxide particles. The vertical acceleration, the displacement, the transmissibility ratio and the damping characteristics are analyzed based on the response of the top plate at different frequencies of base excitation. The results show that the magnetorheological fluid made with nano iron oxide powder has better damping characteristics than that of micron sized iron oxide powder
磁流变液阻尼器作为先进悬架系统的半主动元件已被广泛采用。本文研究了磁场强度、氧化铁颗粒的大小和形状对磁流变流体阻尼特性的影响。采用两级磁流变阻尼器、粘度测量装置、合成的和市购的Fe2O3粉末进行了缩小比例的单自由度四分之一汽车模型的实验研究。采用风冷式电动激振器、数据采集系统、加速度计和Lab view软件对四分之一车型的响应进行采集和分析。x射线衍射和扫描电镜表征了氧化铁颗粒的形貌。分析了顶板在不同基底激励频率下的垂向加速度、位移、传递率和阻尼特性。结果表明,纳米氧化铁粉制备的磁流变液比微米级氧化铁粉具有更好的阻尼特性
{"title":"Study on the Influence of Synthesized Nano Ferrite Powder and Micron Ferrite Powder on Damping of a Single Degree of Freedom System","authors":"Easu Dakshnamoorthy, Siddharthan Arjunan, Amrutha Radhakrishnan, A. Gopal","doi":"10.5755/j02.mech.32055","DOIUrl":"https://doi.org/10.5755/j02.mech.32055","url":null,"abstract":"Magneto Rheological Fluid (MRF) damper has been opted as a promising semi active element of advanced suspension system. This work focuses on the damping nature of magnetorheological fluid under the influence of a magnetic field strength, size and shape of the of the iron oxide particles. A reduced scale single degree of freedom quarter car model with two stage magnetorheological damper, viscosity measurement setup, synthesized and commercially available Fe2O3 powders are used for the experimental study. An air cooled electro-dynamic shaker, Data acquisition system, accelerometers and the Lab view software acquires and analyzes the response of the quarter car model. X-ray Diffraction and Scanning electron microscopy characterize the morphology of iron oxide particles. The vertical acceleration, the displacement, the transmissibility ratio and the damping characteristics are analyzed based on the response of the top plate at different frequencies of base excitation. The results show that the magnetorheological fluid made with nano iron oxide powder has better damping characteristics than that of micron sized iron oxide powder","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43365981","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: 0
期刊
Mechanika
全部 Geobiology Appl. Clay Sci. Geochim. Cosmochim. Acta J. Hydrol. Org. Geochem. Carbon Balance Manage. Contrib. Mineral. Petrol. Int. J. Biometeorol. IZV-PHYS SOLID EART+ J. Atmos. Chem. Acta Oceanolog. Sin. Acta Geophys. ACTA GEOL POL ACTA PETROL SIN ACTA GEOL SIN-ENGL AAPG Bull. Acta Geochimica Adv. Atmos. Sci. Adv. Meteorol. Am. J. Phys. Anthropol. Am. J. Sci. Am. Mineral. Annu. Rev. Earth Planet. Sci. Appl. Geochem. Aquat. Geochem. Ann. Glaciol. Archaeol. Anthropol. Sci. ARCHAEOMETRY ARCT ANTARCT ALP RES Asia-Pac. J. Atmos. Sci. ATMOSPHERE-BASEL Atmos. Res. Aust. J. Earth Sci. Atmos. Chem. Phys. Atmos. Meas. Tech. Basin Res. Big Earth Data BIOGEOSCIENCES Geostand. Geoanal. Res. GEOLOGY Geosci. J. Geochem. J. Geochem. Trans. Geosci. Front. Geol. Ore Deposits Global Biogeochem. Cycles Gondwana Res. Geochem. Int. Geol. J. Geophys. Prospect. Geosci. Model Dev. GEOL BELG GROUNDWATER Hydrogeol. J. Hydrol. Earth Syst. Sci. Hydrol. Processes Int. J. Climatol. Int. J. Earth Sci. Int. Geol. Rev. Int. J. Disaster Risk Reduct. Int. J. Geomech. Int. J. Geog. Inf. Sci. Isl. Arc J. Afr. Earth. Sci. J. Adv. Model. Earth Syst. J APPL METEOROL CLIM J. Atmos. Oceanic Technol. J. Atmos. Sol. Terr. Phys. J. Clim. J. Earth Sci. J. Earth Syst. Sci. J. Environ. Eng. Geophys. J. Geog. Sci. Mineral. Mag. Miner. Deposita Mon. Weather Rev. Nat. Hazards Earth Syst. Sci. Nat. Clim. Change Nat. Geosci. Ocean Dyn. Ocean and Coastal Research npj Clim. Atmos. Sci. Ocean Modell. Ocean Sci. Ore Geol. Rev. OCEAN SCI J Paleontol. J. PALAEOGEOGR PALAEOCL PERIOD MINERAL PETROLOGY+ Phys. Chem. Miner. Polar Sci. Prog. Oceanogr. Quat. Sci. Rev. Q. J. Eng. Geol. Hydrogeol. RADIOCARBON Pure Appl. Geophys. Resour. Geol. Rev. Geophys. Sediment. Geol.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1