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1 – 10 of 37
Article
Publication date: 4 February 2020

Dong Tang, Li Wang, Yang Liu, Ning Liu, Yuzhe Wu and Lie Chen

This paper aims to design and optimize the threaded fastener of leakage current particulate matter (PM) sensor. The corresponding air-tight test is conducted to ensure the…

Abstract

Purpose

This paper aims to design and optimize the threaded fastener of leakage current particulate matter (PM) sensor. The corresponding air-tight test is conducted to ensure the reliability of the installation strategy with screw connection.

Design/methodology/approach

Research on the pressure-deformation curve of seal gasket was conducted and the vibration load of engine was considered for the calculation of the minimum installation pre-tightening force. Simultaneously, the danger threaded section area was calculated, and the carrying capacity was verified. The height of the welding line was studied to ensure the reliability of the application. FEA was carried out to acquire the relationship between local structure size and local stress for continuous improvement of thread connection. The installation torque range was acquired from the torque control principle for the pre-tightening force. The sealing reliability of the connector was proved with leakage.

Findings

The air tightness of the thread connector is proved to be fine. When the pre-tightening force is over 8,000 N, and its length reaches 2 mm, the connector has good reliability at ambient temperature. The tightening torque of 60-74 Nm can guarantee the reliable fixing ability of thread connector, and its plastic non-deformation ability in the process of repeated tearing down.

Originality/value

This paper provides an installation strategy and an optimization of PM sensor, which has a positive effect on the study and the manufacture of PM sensor. It is helpful to further develop PM sensor and after-treatment technology. This kind of real-time monitoring PM sensor needs to be studied further to achieve its commercial application.

Details

Sensor Review, vol. 40 no. 1
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 13 January 2022

Jun Zhang, Yixuan Ma, Zongjin Ren, Tao Bai, Peikai Hu and Zunhao Wang

The purpose of this paper is to improve the reliability of the force measurement system by determining the reliable test range of dynamometer.

Abstract

Purpose

The purpose of this paper is to improve the reliability of the force measurement system by determining the reliable test range of dynamometer.

Design/methodology/approach

Based on the principle of leverage and moment balance, a general force distribution model is applicable in where the test point is located either inside or outside the support region of four three-component force links of dynamometer is established. After corroborating the correctness of the model through verification experiments, the boundary conditions that each three-component force link should satisfy are analyzed by considering the characteristic of the dynamometer components comprehensively. Furthermore, the reliable test range of dynamometer is determined, followed by a calibration experiment to verify its rationality.

Findings

The relationships between the reliable test range and the tested force, the bolt pre-tightening force and the bearing capacity of quartz wafers are clarified. Further, the experimental calibration results show that when the test point is within the reliable test range, the three-directional output voltage of dynamometer has excellent linearity and repeatability. The nonlinearity and repeatability in X-, Y- and Z-directions are all less than 1.1%.

Originality/value

A general mathematical model of force distribution of four three-component force links is constructed, which provides a theoretical basic for the mechanical analysis of multi-sensors’ dynamometer. Comprehensively considering the performance of dynamometer components, the value of measured force and the pre-tightening force, the simultaneous equations of reliable test range are deduced, which limits the boundary of allowable test position of piezoelectric dynamometer.

Details

Sensor Review, vol. 42 no. 2
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 4 September 2017

Dou Wang, Xiaodong Shao, Xiaobo Ge and Simeng Liu

The purpose of this study is to guarantee assembly quality and reduce the number of manufacturing cycles required for an reflector of the large reflector antenna. An optimal…

Abstract

Purpose

The purpose of this study is to guarantee assembly quality and reduce the number of manufacturing cycles required for an reflector of the large reflector antenna. An optimal approach combining a finite element method (FEM) with a genetic algorithm (GA) is developed to simulate and optimize reflector assembly before the assembly stage.

Design/methodology/approach

The chromosomes of GA are encoded with the consideration of the factors that affect the assembly of reflector. The fitness function of the GA consists of the assembly accuracy obtained from simulation, with evaluation of the assembly time consumption and labor cost. The algorithm will terminate when the GA is finished or the simulation results meet the permissible accuracy. Taking the assembly process of the reflector into account, an FEM based on a “life – death element” technique is introduced to quickly and precisely simulate reflector assembly.

Findings

A case study is presented, to which the proposed approach is applied. The results of finite element simulation demonstrate that the proposed FEM can simulate the reflector assembly process with oversimplified modeling and accurate simulation results. The optimal approach provides an accurate and efficient method for reflector assembly sequence planning indicated by the comparison of the measurements and calculation results.

Originality/value

The results also demonstrate that the proposed approach has practical significance for guiding reflector assembly in engineering practice.

Details

Assembly Automation, vol. 37 no. 4
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 9 November 2021

Shufeng Li, Di Zhao and Yating Zhou

Concrete-filled steel tube structures are widely used for their high bearing capacity, good plasticity, good fire resistance and optimal seismic performance. In order to give full…

Abstract

Purpose

Concrete-filled steel tube structures are widely used for their high bearing capacity, good plasticity, good fire resistance and optimal seismic performance. In order to give full play to the advantages of concrete-filled steel tube, this paper proposes a prefabricated concrete-filled steel tube frame joint.

Design/methodology/approach

The concrete-filled steel tube column and beam are connected by high-strength bolted end-plate, and the steel bars in the concrete beam are welded vertically with the end-plates through the enlarged pier head. In addition, the finite element software ABAQUS is used numerically to study the seismic performance of the structure.

Findings

The ductility coefficient of the joint is in 1.72–6.82, and greater than 2.26 as a whole. The equivalent viscous damping coefficient of the joint is 0.13–3.03, indicating that the structure has good energy dissipation capacity.

Originality/value

The structure is convenient for construction and overcomes the shortcomings of the previous on-site welding and on-site concrete pouring. The high-strength bolted end-plate connection can effectively transfer the load, and each component can give play to its material characteristics.

Details

International Journal of Structural Integrity, vol. 13 no. 2
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 6 July 2015

Shaochun Wang and Ru Zhao

The purpose of this paper is to describe a technical creation called a constant-force cylinder, which exhibits more advantages in providing constant force in a low-gravity…

1109

Abstract

Purpose

The purpose of this paper is to describe a technical creation called a constant-force cylinder, which exhibits more advantages in providing constant force in a low-gravity environment than some existing methods.

Design/methodology/approach

The authors design the constant-force cylinder with simple ideas and realistic applicability that is easy to achieve. The authors analyze and formulate the cylinder, and explain how the realization of constant force and low gravity are obtained during the experiment by calculations. Force analysis and simple mathematics/statistics are used in the calculation.

Findings

The authors prove the effectiveness and accuracy of the constant and low-gravity properties of the new cylinder. In addition, the authors formulate the acceleration value to drive the cylinder which is flexible and easy to be adjusted during the experiment.

Practical implications

The constant-force cylinder can be functioning in a low-gravity environment with simple structures and economical extensions to real-world applications.

Originality/value

This is an innovative design of a constant-force cylinder under the low-gravity environment. In the experiment, the new cylinder was revised from an ordinary and economic cylinder with constant force and the applicability easy to be realized in practice.

Details

Aircraft Engineering and Aerospace Technology: An International Journal, vol. 87 no. 4
Type: Research Article
ISSN: 0002-2667

Keywords

Article
Publication date: 21 October 2021

Feng Gao, Pan-Pan Li and Yan Li

For ball screw feed system, a sudden start or stop has a great influence on the transmission stiffness, so the axial stiffness mutation of feed system will occur. The purpose of…

Abstract

Purpose

For ball screw feed system, a sudden start or stop has a great influence on the transmission stiffness, so the axial stiffness mutation of feed system will occur. The purpose of this paper is to study the influence of acceleration on the transmission stiffness and dynamic characteristics of the ball screw feed system.

Design/methodology/approach

Taking the ball screw feed system as a research object, on the basis of the Hertz contact theory and the mixed element method, axial stiffness model and dynamic model are established. And the system stability was analyzed by the time history diagram and Phase-plane portrait diagram. The feed system was analyzed theoretically and experimentally, the experimental results are in good agreement with the model results.

Findings

Lead screw lead angle, preload, load and start acceleration affected ball-screw pair, bearing and transmission stiffness. And the load, nut contact stiffness, bearing contact stiffness, preload have a large effect on the transmission stiffness. The results show that a certain acceleration value will make the axial stiffness abrupt change.

Originality/value

This research provides a useful theoretical support for ensuring a good dynamic for the ball screw feed system.

Details

Industrial Lubrication and Tribology, vol. 73 no. 10
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 1 July 2020

Zhang Jun, Muhammad Ayaz Akbar, Wang Xin lei and Danaish

The purpose of this study is to present the optimization of the design and measurement principle of a six-component force/thrust measurement stand. This study highlights some key…

Abstract

Purpose

The purpose of this study is to present the optimization of the design and measurement principle of a six-component force/thrust measurement stand. This study highlights some key problems found in previous studies and proposes improvements in design and measurement principles.

Design/methodology/approach

The numerical simulation approach is used to verify the proposed improvements. An improved design and measurement principle are proposed and to verify the proposed improvements, simulation experiments are conducted. The data obtained from simulations are analyzed through the proposed improved measurement principle. The proposed stand is capable of measuring the main thrust and other components as pitch, yaw and roll. The stand is capable of measuring the main thrust more than 50,000 N and orthogonal thrust components more than 1,000 N. Improved design of measurement stand is also capable of measuring moments in three-axis more than 150 Nm. Thrust stand consists of two main sections: front and rare. Stand consists of seven piezoelectric force sensors to measure all components of force.

Findings

The simulations experiments and basic theoretical laws of kinematics prove that the proposed design indeed improves the precision of measurement and also enhance the efficiency of design. Evaluation results show that the measurement stand designed is highly functional. Non-linearity, coupling and repeatability errors are found to be within acceptable range during numerical simulations.

Originality/value

This study is unique in this kind. This study identifies the key problems found in previous studies and proposes an improved design and measurement principle. This study provides evidence for the improvements to be really functional and necessary.

Details

Journal of Engineering, Design and Technology , vol. 18 no. 5
Type: Research Article
ISSN: 1726-0531

Keywords

Open Access
Article
Publication date: 15 November 2022

Liyao Song, Bai Chen, Bo Li, Rupeng Zhu and Dan Wang

The supercritical design of tail rotor drive shaft has attracted more attention in helicopter design due to its high power–weight ratio and low maintenance cost. However, there…

Abstract

Purpose

The supercritical design of tail rotor drive shaft has attracted more attention in helicopter design due to its high power–weight ratio and low maintenance cost. However, there exists excessive vibration when the shaft passes through the critical frequency. Dry friction damper is the equipment applied to the drive shaft to suppress the excessive vibration. In order to figure out the damping mechanism of the dry friction damper and improve the damping efficiency, the dynamic model of the shaft/damper system is established based on the Jeffcott rotor model.

Design/methodology/approach

The typical frequency response of the system is studied through bifurcation diagrams, amplitude-frequency characteristic curves and waterfall frequency response spectrum. The typical transient responses under frequency sweeps are also obtained.

Findings

The results show that the response of the system changes from periodic no-rub motion to quasi-periodic rub-impact motion, and then to synchronous full annular rub-impact, and finally, back to periodic no-rub motion. The slip of the rub-impact ring improves the stability of the system. Besides, the effects of the system parameters including critical dry friction force, rub-impact friction coefficient, initial clearance on the stability and the vibration damping capacity are studied. It is observed that the stability changes significantly varying the three parameters respectively. The vibration damping capacity is mainly affected by the critical dry friction force and the initial clearance.

Originality/value

Presented results provide guidance for the design of the dry friction damper.

Details

Journal of Intelligent Manufacturing and Special Equipment, vol. 3 no. 2
Type: Research Article
ISSN: 2633-6596

Keywords

Article
Publication date: 10 July 2019

Zhen Chen, Zhenqqi Gu and Tao Jiang

The main purpose of this paper is to gain a better understanding of the transient aerodynamic characteristics of moving windshield wipers. In addition, this paper also strives to…

Abstract

Purpose

The main purpose of this paper is to gain a better understanding of the transient aerodynamic characteristics of moving windshield wipers. In addition, this paper also strives to illustrate and clarify how the wiper motion impacts the airflow structure; the aerodynamic interaction of two wipers is also discussed.

Design/methodology/approach

A standard vehicle model proposed by the Motor Industry Research Association and a pair of simplified bone wipers are introduced, and a dynamic mesh technique and user-defined functions are used to achieve the wiper motion. Finite volume methods and large eddy simulation (LES) are used to simulate the transient airflow field. The simulation results are validated through the wind tunnel test.

Findings

The results obtained from the study are presented graphically, and pressure, velocity distributions, airflow structures, aerodynamic drag and lift force are shown. Significant influences of wiper motion on airflow structures are achieved. The maximum value of aerodynamic lift and drag force exists when wipers are rotating and there is a certain change rule. The aerodynamic lift and drag force when wipers are rotating downward is greater than when wipers are rotating upward, and the force when rotating upward is greater than that when steady. The aerodynamic lift and drag forces of the driver-side wiper is greater than those of the passenger-side wiper.

Originality/value

The LES method in combination with dynamic mesh technique to study the transient aerodynamic characteristics of windshield wipers is relatively new.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 29 no. 8
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 28 December 2020

Nanshan Wang, Heng Liu, Qidan Wang, Shemiao Qi and Yi Liu

This study aims to obtain the dynamic behaviours of cracked rod-fastening rotor bearing system (RFBS), and experimental investigation was carried out to examine the dynamic…

Abstract

Purpose

This study aims to obtain the dynamic behaviours of cracked rod-fastening rotor bearing system (RFBS), and experimental investigation was carried out to examine the dynamic characteristics of this kind of assembled rotor bearing system with a transverse crack passing through the critical speed.

Design/methodology/approach

An experimental test rig of cracked RFBS was established for examining the vibration behaviours between intact and cracked system. The crack on the surface of a fastening rod was simulated by wire-electrode cutting processing method. The comprehensive analysis method of vibration was used to obtain the dynamic characteristics such as vibration amplitude, acceleration and whirling orbits before and after the critical speed as well as the instantaneous response in the process of speed up.

Findings

Some experimental vibration datum is obtained for cracked RFBS. The appearance of a crack will introduce the initial bending and make the vibration amplitude, acceleration and instant response in the process of speed up increase greatly as well as the change of whirling orbits.

Originality/value

The actual vibration characteristics for this complex assembled rotor system with a transverse crack are given passing through the critical speed. It can provide some useful help for monitoring the vibration behaviours of this kind of assembled rotor system as well as the detection of the crack fault.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2020-0260/

Details

Industrial Lubrication and Tribology, vol. 73 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

1 – 10 of 37