Pub Date : 2024-04-02DOI: 10.56651/lqdtu.jst.v19.n01.640
Xuan Hiep Trinh
This article presents the development and production process of a glove designed for rehabilitation, and enhancing object manipulation capabilities for individuals with hand mobility limitations, using soft finger design. The soft fingers are constructed from a composite structure consisting of silicone rubber material. An automated calculation program is created in Python and integrated with Abaqus/CAE software, enabling the concurrent exploration of numerous parameters governing the soft fingers to choose a rational design of glove. Experimental tests reveal that the error of the experiment and simulation results is less than 7.8%. Furthermore, these deformable soft fingers can closely mimic the contours of human fingers. Leveraging the successful construction of the soft fingers, a corresponding soft glove is manufactured. Preliminary validated experiments demonstrate the effectiveness of these soft gloves in aiding patients with diverse exercise rehabilitation. Additionally, they provide support for basic tasks such as grasping objects weighing approximately 600 grams.
{"title":"DESIGN AND MANUFACTURE OF SOFT FINGER-GLOVES FOR REHABILITATION OF INDIVIDUALS WITH DISABILITIES","authors":"Xuan Hiep Trinh","doi":"10.56651/lqdtu.jst.v19.n01.640","DOIUrl":"https://doi.org/10.56651/lqdtu.jst.v19.n01.640","url":null,"abstract":"This article presents the development and production process of a glove designed for rehabilitation, and enhancing object manipulation capabilities for individuals with hand mobility limitations, using soft finger design. The soft fingers are constructed from a composite structure consisting of silicone rubber material. An automated calculation program is created in Python and integrated with Abaqus/CAE software, enabling the concurrent exploration of numerous parameters governing the soft fingers to choose a rational design of glove. Experimental tests reveal that the error of the experiment and simulation results is less than 7.8%. Furthermore, these deformable soft fingers can closely mimic the contours of human fingers. Leveraging the successful construction of the soft fingers, a corresponding soft glove is manufactured. Preliminary validated experiments demonstrate the effectiveness of these soft gloves in aiding patients with diverse exercise rehabilitation. Additionally, they provide support for basic tasks such as grasping objects weighing approximately 600 grams.","PeriodicalId":509166,"journal":{"name":"Journal of Science and Technique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140753571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-02DOI: 10.56651/lqdtu.jst.v19.n01.646
This article presents a thermo-elastic static analysis of the FG-CNTRC cylinderical shell subjected to a thermo-mechanical load. The temperature is assumed to vary through the thickness, and the temperature distribution is derived from the heat transfer formula. The gorvening equations of thermoelastic analysis are established by using the higher-order shear deformation theory, including the transverse normal stress effect. The material properties of FG-CNTRC are temperature-dependent. Using an analytical solution that used the single trigonometric series and the Laplace transformation to solve these equations of shell with the different boundary conditions. The present approach is validated by comparing the results with published results. The effects of different boundary conditions and temperatures on the displacement and stresses of the FG-CNTRC cylindrical shells are investigated. The results show the jumping variation of the stress components at the boundary position. Besides, when the temperature increases, the maximum absolute value of the axial stress increases while that of the circumferential stress decreases.
{"title":"STATIC ANALYSIS OF FG-CNTRC CYLINDRICAL SHELL SUBJECTED TO THERMO-MECHANICAL LOAD WITH TEMPERATURE-DEPENDENT PROPERTIES","authors":"","doi":"10.56651/lqdtu.jst.v19.n01.646","DOIUrl":"https://doi.org/10.56651/lqdtu.jst.v19.n01.646","url":null,"abstract":"This article presents a thermo-elastic static analysis of the FG-CNTRC cylinderical shell subjected to a thermo-mechanical load. The temperature is assumed to vary through the thickness, and the temperature distribution is derived from the heat transfer formula. The gorvening equations of thermoelastic analysis are established by using the higher-order shear deformation theory, including the transverse normal stress effect. The material properties of FG-CNTRC are temperature-dependent. Using an analytical solution that used the single trigonometric series and the Laplace transformation to solve these equations of shell with the different boundary conditions. The present approach is validated by comparing the results with published results. The effects of different boundary conditions and temperatures on the displacement and stresses of the FG-CNTRC cylindrical shells are investigated. The results show the jumping variation of the stress components at the boundary position. Besides, when the temperature increases, the maximum absolute value of the axial stress increases while that of the circumferential stress decreases.","PeriodicalId":509166,"journal":{"name":"Journal of Science and Technique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140755194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-02DOI: 10.56651/lqdtu.jst.v19.n01.733
Tien Hoa Nguyen
This article presents a method of calculating the simulation of flow in solid fuel combustion chamber, which applied to the two-layer mixed solid propellant motor, using simulation software Ansys Fluent. The regression of burning surface of the propellant is simulated using dynamic meshing tool combined with user-defined functions (UDF), written in C++ programming language. The author proposes a method to calculate the average fire rate for mixed solid fuel, thereby simplifying the simulation process and still get results corresponding to the experimental results. The calculation thrust-time curve has a profile similar to the experimental results. The maximum thrust achieved during the steady burning phase is 4.98 kN, the correspoding experimental value is 5.0 kN.
本文介绍了一种模拟固体燃料燃烧室内流动的计算方法，该方法适用于双层混合固体推进剂发动机，使用的模拟软件是 Ansys Fluent。推进剂燃烧面的回归是利用动态网格工具结合用户定义函数（UDF）进行模拟的，UDF 是用 C++ 编程语言编写的。作者提出了一种计算混合固体燃料平均着火率的方法，从而简化了模拟过程，并仍能得到与实验结果相对应的结果。计算推力-时间曲线的轮廓与实验结果相似。稳定燃烧阶段达到的最大推力为 4.98 kN，相应的实验值为 5.0 kN。
{"title":"CALCULATION OF FLOW SIMULATION IN COMBUSTION CHAMBER OF SOLID FUEL MOTOR WITH TWO-LAYER MIXED PROPELLANT","authors":"Tien Hoa Nguyen","doi":"10.56651/lqdtu.jst.v19.n01.733","DOIUrl":"https://doi.org/10.56651/lqdtu.jst.v19.n01.733","url":null,"abstract":"This article presents a method of calculating the simulation of flow in solid fuel combustion chamber, which applied to the two-layer mixed solid propellant motor, using simulation software Ansys Fluent. The regression of burning surface of the propellant is simulated using dynamic meshing tool combined with user-defined functions (UDF), written in C++ programming language. The author proposes a method to calculate the average fire rate for mixed solid fuel, thereby simplifying the simulation process and still get results corresponding to the experimental results. The calculation thrust-time curve has a profile similar to the experimental results. The maximum thrust achieved during the steady burning phase is 4.98 kN, the correspoding experimental value is 5.0 kN.","PeriodicalId":509166,"journal":{"name":"Journal of Science and Technique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140752146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-02DOI: 10.56651/lqdtu.jst.v19.n01.639
N. D. Tran
This article presents the results of investigating FGM closed cylindrical shells using quasi-3D higher-order shear deformation theory. The law of volume distribution of materials according to the power function. In this article, the results of the analysis of the stress state at the clamped boundary area of the FGM cylindrical shell subjected to radial local loads distributed according to different laws. The mathematical model and the calculation program in Maple are compared and verified with the published results. The article has shown that at the clamped boundary edge, the values of stress components increase sharply, and at the same time, the strong influence of the load parameters (the variation law, the size of the load area), the power-law index on the values and distribution of stress components in the boundary area is demonstrated.
本文介绍了利用准三维高阶剪切变形理论研究 FGM 闭合圆柱形壳体的结果。根据幂函数的材料体积分布规律。本文分析了在按照不同规律分布的径向局部载荷作用下，FGM 圆柱壳夹紧边界区域的应力状态。数学模型和 Maple 计算程序与已发表的结果进行了比较和验证。文章表明，在夹紧边界边缘，应力分量的值急剧增加，同时，载荷参数（变化规律、载荷区域大小）、幂律指数对边界区域应力分量的值和分布有很大影响。
{"title":"INVESTIGATING THE STRESS DISTRIBUTION ON THE CLAMPED BOUNDARY OF FGM CYLINDRICAL SHELLS SUBJECTED TO STATIC LOADS USING THE QUASI-3D HIGHER-ORDER SHEAR DEFORMATION THEORY","authors":"N. D. Tran","doi":"10.56651/lqdtu.jst.v19.n01.639","DOIUrl":"https://doi.org/10.56651/lqdtu.jst.v19.n01.639","url":null,"abstract":"This article presents the results of investigating FGM closed cylindrical shells using quasi-3D higher-order shear deformation theory. The law of volume distribution of materials according to the power function. In this article, the results of the analysis of the stress state at the clamped boundary area of the FGM cylindrical shell subjected to radial local loads distributed according to different laws. The mathematical model and the calculation program in Maple are compared and verified with the published results. The article has shown that at the clamped boundary edge, the values of stress components increase sharply, and at the same time, the strong influence of the load parameters (the variation law, the size of the load area), the power-law index on the values and distribution of stress components in the boundary area is demonstrated.","PeriodicalId":509166,"journal":{"name":"Journal of Science and Technique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140753425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-02DOI: 10.56651/lqdtu.jst.v19.n01.719
Trung Dung Nguyen
The turbulent mixing layer is a phenomenon that occurs and has many applications in aeronautical engineering. The study of mixing layer turbulence by the numerical method is suitable under domestic conditions. Two numerical simulation methods are used in most studies including, direct numerical simulation DNS and large eddy simulation LES, while there are very few studies using detached eddy simulation DES. In this article, the authors use numerical simulation methods evolving Reynolds average Navier-Stokes simulation RANS and detached eddy simulation DES to propose a numerical simulation model that allows to study of the aerodynamic characteristics of the turbulent flow interaction. RANS is used to evaluate grid independence. With the selected mesh, two models counting the DES-2D model and the DES-3D model are conducted. Processing velocity field data with Matlab code, the results show that the average flow behavior has closely followed the experimental results, while the turbulent kinetic energy still has a large error. POD and Q-criterion analysis has shown some large coherent structures in the interaction region.
湍流混合层是航空工程中经常出现和应用的一种现象。用数值方法研究混合层湍流适合国内条件。大多数研究采用两种数值模拟方法，包括直接数值模拟 DNS 和大涡模拟 LES，而采用分离涡模拟 DES 的研究很少。在本文中，作者使用不断演化的雷诺平均纳维-斯托克斯模拟 RANS 和分离涡模拟 DES 数值模拟方法，提出了一种可以研究湍流相互作用气动特性的数值模拟模型。RANS 用于评估网格的独立性。利用选定的网格，进行了 DES-2D 模型和 DES-3D 模型的计算。用 Matlab 代码处理速度场数据，结果表明平均流动行为与实验结果密切相关，而湍流动能仍有较大误差。POD 和 Q 准则分析表明，在相互作用区域存在一些大的相干结构。
{"title":"DETACHED EDDY SIMULATIONS IN THE STUDY OF AERODYNAMIC CHARACTERISTICS OF THE TURBULENT MIXING LAYER","authors":"Trung Dung Nguyen","doi":"10.56651/lqdtu.jst.v19.n01.719","DOIUrl":"https://doi.org/10.56651/lqdtu.jst.v19.n01.719","url":null,"abstract":"The turbulent mixing layer is a phenomenon that occurs and has many applications in aeronautical engineering. The study of mixing layer turbulence by the numerical method is suitable under domestic conditions. Two numerical simulation methods are used in most studies including, direct numerical simulation DNS and large eddy simulation LES, while there are very few studies using detached eddy simulation DES. In this article, the authors use numerical simulation methods evolving Reynolds average Navier-Stokes simulation RANS and detached eddy simulation DES to propose a numerical simulation model that allows to study of the aerodynamic characteristics of the turbulent flow interaction. RANS is used to evaluate grid independence. With the selected mesh, two models counting the DES-2D model and the DES-3D model are conducted. Processing velocity field data with Matlab code, the results show that the average flow behavior has closely followed the experimental results, while the turbulent kinetic energy still has a large error. POD and Q-criterion analysis has shown some large coherent structures in the interaction region.","PeriodicalId":509166,"journal":{"name":"Journal of Science and Technique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140752179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-02DOI: 10.56651/lqdtu.jst.v19.n01.720
Duc Tiep Le
This article proposes a plan to improve the quality of the output AC voltage of the H-bridge inverter based on the change of the law of distribution of zero and non-zero voltage states of the inverter when controlling the H-bridge inverter. The results were surveyed, analyzed, compared, and evaluated by simulation model on Matlab-Simulink software. In which the fundamental harmonic level index and the total harmonic distortion (THD) are used to compare, analyze and evaluate the quality of H-bridge inverter output voltages in different switching modes such as pulse width modulation according to sine law (sinPWM), pulse width adjustment (SIR) and the proposed improved pulse width modulation law. The results show that the H-bridge inverter output voltage form with improved sequential switching law gives better quality than the original. This result has practical significance in the research and design of power conversion circuits for AC power transmission systems.
本文根据控制 H 桥逆变器时逆变器零电压和非零电压状态分布规律的变化，提出了改善 H 桥逆变器输出交流电压质量的方案。通过 Matlab-Simulink 软件上的仿真模型对结果进行了调查、分析、比较和评估。其中，基波谐波电平指数和总谐波失真（THD）用于比较、分析和评估不同开关模式下 H 桥逆变器输出电压的质量，如根据正弦规律的脉宽调制（sinPWM）、脉宽调整（SIR）和提议的改进脉宽调制规律。结果表明，采用改进型顺序开关规律的 H 桥逆变器输出电压形式比原来的质量更好。这一结果对研究和设计交流输电系统的功率转换电路具有实际意义。
{"title":"POWER QUALITY ENHANCEMENT OF H-BRIDGE INDIRECT OUTPUT VOLTAGE BY CHANGING TIME DISTRIBUTION OF VOLTAGE STATUS 0 AND DIFFERENT 0","authors":"Duc Tiep Le","doi":"10.56651/lqdtu.jst.v19.n01.720","DOIUrl":"https://doi.org/10.56651/lqdtu.jst.v19.n01.720","url":null,"abstract":"This article proposes a plan to improve the quality of the output AC voltage of the H-bridge inverter based on the change of the law of distribution of zero and non-zero voltage states of the inverter when controlling the H-bridge inverter. The results were surveyed, analyzed, compared, and evaluated by simulation model on Matlab-Simulink software. In which the fundamental harmonic level index and the total harmonic distortion (THD) are used to compare, analyze and evaluate the quality of H-bridge inverter output voltages in different switching modes such as pulse width modulation according to sine law (sinPWM), pulse width adjustment (SIR) and the proposed improved pulse width modulation law. The results show that the H-bridge inverter output voltage form with improved sequential switching law gives better quality than the original. This result has practical significance in the research and design of power conversion circuits for AC power transmission systems.","PeriodicalId":509166,"journal":{"name":"Journal of Science and Technique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140753341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-02DOI: 10.56651/lqdtu.jst.v19.n01.725
Van Duong Le
This article presents the dynamic model of a truck-mounted hydraulic knuckle boom crane when lifting loads operations. The article develops a dynamic model of a hydraulic knuckle boom crane considering the viscoelasticity of the boom-luff cylinder, knuckle cylinder, and extension cylinder. Modeling is constituted for the complex operation of the crane when lifting loads, in which the boom-luff cylinder, knuckle cylinder, and extension cylinder are simultaneously activated. The Lagrange equation of type II is used to build a system of differential equations describing the motion of the mechanical system. On that basis, the article analyzes the dynamic parameters of the crane when lifting loads operations. The results of the article are the basis for the hydraulic knuckle boom crane control problem to improve the performance and reliability of the crane during operation.
本文介绍了汽车式液压折臂起重机在起重作业时的动态模型。文章建立了液压折臂式起重机的动态模型，其中考虑到了臂架油缸、折臂油缸和伸缩油缸的粘弹性。该模型是针对起重机在起吊负载时的复杂操作而建立的，在这种情况下，臂架油缸、折臂油缸和伸展油缸同时启动。拉格朗日方程 II 型用于建立描述机械系统运动的微分方程系统。在此基础上，文章分析了起重机在起重作业时的动态参数。文章的结果是液压折臂式起重机控制问题的基础，以提高起重机在运行过程中的性能和可靠性。
{"title":"DYNAMIC ANALYSIS OF THE HYDRAULIC KNUCKLE BOOM CRANE WHEN LIFTING LOADS OPERATIONS","authors":"Van Duong Le","doi":"10.56651/lqdtu.jst.v19.n01.725","DOIUrl":"https://doi.org/10.56651/lqdtu.jst.v19.n01.725","url":null,"abstract":"This article presents the dynamic model of a truck-mounted hydraulic knuckle boom crane when lifting loads operations. The article develops a dynamic model of a hydraulic knuckle boom crane considering the viscoelasticity of the boom-luff cylinder, knuckle cylinder, and extension cylinder. Modeling is constituted for the complex operation of the crane when lifting loads, in which the boom-luff cylinder, knuckle cylinder, and extension cylinder are simultaneously activated. The Lagrange equation of type II is used to build a system of differential equations describing the motion of the mechanical system. On that basis, the article analyzes the dynamic parameters of the crane when lifting loads operations. The results of the article are the basis for the hydraulic knuckle boom crane control problem to improve the performance and reliability of the crane during operation.","PeriodicalId":509166,"journal":{"name":"Journal of Science and Technique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140752978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-02DOI: 10.56651/lqdtu.jst.v19.n01.636
Tien Duong Le
This article presents the results of stress field calculations for the first stage compressor impeller using the one-way fluid-structure interaction (FSI) method, which helps determine stress concentration zones and safety factors. Numerical analysis conducted with Ansys software reveals that stress concentration occurs near the blade root on the suction side and within the blade lock-disc zone. In these stress concentration zones, such as the blade lock-disc zone and blade suction side, the minimum safety factor is found to be above 2.27. These findings serve as a foundation for future research on impeller stress fields using two-way FSI methods and for providing recommendations to optimize the stress concentration field in the compressor disc.
{"title":"THE STRESS FIELD OF THE FIRST STAGE COMPRESSOR IMPELLER OF THE TV3-117 GAS TURBINE ENGINE USING NUMERICAL SIMULATION","authors":"Tien Duong Le","doi":"10.56651/lqdtu.jst.v19.n01.636","DOIUrl":"https://doi.org/10.56651/lqdtu.jst.v19.n01.636","url":null,"abstract":"This article presents the results of stress field calculations for the first stage compressor impeller using the one-way fluid-structure interaction (FSI) method, which helps determine stress concentration zones and safety factors. Numerical analysis conducted with Ansys software reveals that stress concentration occurs near the blade root on the suction side and within the blade lock-disc zone. In these stress concentration zones, such as the blade lock-disc zone and blade suction side, the minimum safety factor is found to be above 2.27. These findings serve as a foundation for future research on impeller stress fields using two-way FSI methods and for providing recommendations to optimize the stress concentration field in the compressor disc.","PeriodicalId":509166,"journal":{"name":"Journal of Science and Technique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140754870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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