Gear Checking for the Sun Gear in Planet-Gear Reducer based on Practical Engineering Application

A 2D electrohydraulic proportional directional valve is proposed, which integrates both direct and pilot operation of the valve. In this valve, the output magnetic force of the proportional solenoid is converted to rotate the spool through a thrust-torsion coupling and thus the pressure in the valve sensitive chamber is varied. The varied pressure exerted on the areas of the spool end produces a hydrostatic force to move the spool linearly, which will rotate the spool reversely. Theoretical analysis is carried to the proposed valve and the effects of the key geometric parameters on the dynamic characteristics of the 2D valve and stability are investigated. Experiments are also designed to access to the characteristics of the valve working under direct and pilot operation. The 2D electrohydraulic valve can work properly for both direct operation and pilot operation. The hysteresis and frequency response are measured and the results are within the acceptable range in practical engineering application required of the directional proportional valve.

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Planetary Gearbox Dynamic Modeling Considering Bearing Clearance and Sun Gear Tooth Crack

Sensors ◽

10.3390/s21082638 ◽

2021 ◽

Vol 21 (8) ◽

pp. 2638

Author(s):

Xianhua Chen ◽

Xingkai Yang ◽

Ming J. Zuo ◽

Zhigang Tian

Keyword(s):

Dynamic Model ◽

Dynamic Modeling ◽

Failure Modes ◽

Gear Tooth ◽

Working Environment ◽

The Sun ◽

Planetary Gearbox ◽

Bearing Clearance ◽

Vibration Responses ◽

Planet Gear

Planetary gearbox systems are critical mechanical components in heavy machinery such as wind turbines. They may suffer from various failure modes, due to the harsh working environment. Dynamic modeling is a useful method to support early fault detection for enhancing reliability and reducing maintenance costs. However, reported studies have not considered the sun gear tooth crack and bearing clearance simultaneously to analyze their combined effect on vibration characteristics of planetary gearboxes. In this paper, a dynamic model is developed for planetary gearboxes considering the clearance of planet gear, sun gear, and carrier bearings, as well as sun gear tooth crack levels. Bearing forces are calculated considering bearing clearance, and the dynamic model equations are updated accordingly. The results reveal that the combination of bearing clearances can affect the vibration response with sun gear tooth crack by increasing the kurtosis. It is found that the effect of planet gear bearing clearance is very small, while the sun gear and carrier bearing clearance has clear impact on the vibration responses. These findings suggest that the incorporation of bearing clearance is important for planetary gearbox dynamic modeling.

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Experimental Study on Influence of Temperature to Control Performance for Viscoelastic Materials Pounding Tuned Mass Damper

Frontiers in Materials ◽

10.3389/fmats.2021.676405 ◽

2021 ◽

Vol 8 ◽

Author(s):

Dehui Ye ◽

Jie Tan ◽

Yabin Liang ◽

Qian Feng

Keyword(s):

Engineering Application ◽

Tuned Mass Damper ◽

Frame Structure ◽

Force Model ◽

Viscoelastic Materials ◽

Mass System ◽

Mass Damper ◽

Different Temperatures ◽

Practical Engineering ◽

Portal Frame Structure

The pounding tuned mass damper (PTMD) is a novel passive damper that absorbs and dissipates energy by an auxiliary tuned spring-mass system. Viscoelastic materials are attached to the interface of the limitation collar in the PTMD so that the energy dissipation capacity can be enhanced. Previous studies have successfully demonstrated the effectiveness of PTMD at room temperature. However, in practice, the PTMD may face a broad temperature range, which can affect the mechanical properties of the viscoelastic materials. Thus, the study of vibration control effectiveness of PTMD at different temperatures is of great significance for its practical engineering application. In this paper, a series of experiments were conducted to investigate the performance of a PTMD in a temperature-controlled environment. A PTMD device was designed to suppress the vibration of a portal frame structure and tested across environmental temperatures ranging from –20°C to 45°C. The displacement reduction ratios demonstrated the temperature robustness of the PTMD. Additionally, the numerical results validated the accuracy of the pounding force model and the performance of PTMD.

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Study on Flexural Behavior of Pre-Stressed Concrete Hollow Slabs Strengthen with CFRP

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.446-447.1413 ◽

2013 ◽

Vol 446-447 ◽

pp. 1413-1416

Author(s):

Bo Wang ◽

Juan Han

Keyword(s):

Experimental Method ◽

Engineering Application ◽

Flexural Behavior ◽

Experimental Basis ◽

Concentrated Force ◽

Disaster Area ◽

Practical Engineering ◽

Symmetrical Load

The purpose of this paper is to focus on studying its flexural behavior after different damages pre-stressed concrete hollow slab is strengthened with CFRP. By the experimental method, twelve residential pre-stressed concrete hollow slabs are tested under concentrated force at the two points of the symmetrical load in order to analyze both flexural behavior and effects factored by different bonding modes. The conclusion can be drawn that the flexural behavior of pre-stressed concrete hollow slabs strengthened with CFRP is well-tried. It provides design suggestions and reference for pre-stressed concrete hollow slabs strengthened with CFRP, and also provides an experimental basis for the repairing and reinforcing practical engineering application in Wenchuan disaster area.

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A Fault-Tolerant Offset Algorithm for Measured Data with Defects

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.902.344 ◽

2014 ◽

Vol 902 ◽

pp. 344-350

Author(s):

Xiang Jia Li ◽

Ning Dai ◽

Wen He Liao ◽

Yu Chun Sun ◽

Yong Bo Wang

Keyword(s):

High Efficiency ◽

Fault Tolerant ◽

Engineering Application ◽

Measured Data ◽

Sphere Model ◽

High Quality ◽

Fitting Method ◽

Enveloping Surface ◽

Practical Engineering ◽

Offset Surface

Offsetting of measured data, as a basic geometric operation, has already been widely used in many areas, like reverse engineering, rapid prototyping and NC machining. However, measured data always carry typical defects like caves and singular points. A fault-tolerant offset method is proposed to create the high quality offset surface of measured data with such defects. Firstly, we generated an expansion sphere model of measured data with the radius equivalent to the offset length. Secondly, using the computational geometry application of convex hull, we acquire the data of outermost enveloping surface of this expansion sphere model. Finally, we use local MLS projection fitting method to wipe out existing defects, and generate the high-quality triangular mesh surface of the offset model. The offset surface generated by this method is suitable for practical engineering application due to its high efficiency and accuracy.

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Recent advances in reliability analysis of aeroengine rotor system: a review

International Journal of Structural Integrity ◽

10.1108/ijsi-10-2021-0111 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Xue-Qin Li ◽

Lu-Kai Song ◽

Guang-Chen Bai

Keyword(s):

Reliability Analysis ◽

Surrogate Model ◽

Engineering Application ◽

Rotor System ◽

Engineering Structures ◽

Content Type ◽

Reliability Design ◽

Rotor Systems ◽

Practical Engineering ◽

Complex Engineering

PurposeTo provide valuable information for scholars to grasp the current situations, hotspots and future development trends of reliability analysis area.Design/methodology/approachIn this paper, recent researches on efficient reliability analysis and applications in complex engineering structures like aeroengine rotor systems are reviewd.FindingsThe recent reliability analysis advances of engineering application in aeroengine rotor system are highlighted, it is worth pointing out that the surrogate model methods hold great efficiency and accuracy advantages in the complex reliability analysis of aeroengine rotor system, since its strong computing power can effectively reduce the analysis time consumption and accelerate the development procedures of aeroengine. Moreover, considering the multi-objective, multi-disciplinary, high-dimensionality and time-varying problems are the common problems in various complex engineering fields, the surrogate model methods and its developed methods also have broad application prospects in the future.Originality/valueFor the strong demand for efficient reliability design technique, this review paper may help to highlights the benefits of reliability analysis methods not only in academia but also in practical engineering application like aeroengine rotor system.

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Vibration Control of Blade Section Based on Sliding Mode PI Tracking Method and OPC Technology

Shock and Vibration ◽

10.1155/2019/8314898 ◽

2019 ◽

Vol 2019 ◽

pp. 1-12 ◽

Cited By ~ 1

Author(s):

Tingrui Liu

Keyword(s):

Vibration Control ◽

Sliding Mode ◽

Engineering Application ◽

Control Input ◽

Pi Method ◽

Opc Technology ◽

Practical Engineering ◽

Blade Section ◽

The Stability ◽

And Control

Vibration control of the blade section of a wind turbine is investigated based on the sliding mode proportional-integral (SM-PI) method, i.e., sliding mode control (SMC) based on a PI controller. The structure is modeled as a 2D pretwisted blade section integrated with calculation of structural damping, which is subjected to flap/lead-lag vibrations of instability. To facilitate the hardware implementation of the control algorithm, the SM-PI method is applied to realize tracking for limited displacements and velocities. The SM-PI algorithm is a novel SMC algorithm based on the nominal model. It combines the effectiveness of the sliding mode algorithm for disturbance control and the stability of PID control for practical engineering application. The SM-PI design and stability analysis are discussed, with superiority and robustness and convergency control demonstrated. An experimental platform based on human-computer interaction using OPC technology is implemented, with position tracking for displacement and control input signal illustrated. The platform verifies the feasibility and effectiveness of the SM-PI algorithm in solving practical engineering problems, with online tuning of PI parameters realized by applying OPC technology.

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Superior Research for Selection of Bracing Structure of Deep Pit Foundation Based on Fussy Theory

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.838-841.214 ◽

2013 ◽

Vol 838-841 ◽

pp. 214-218

Author(s):

Dong Li

Keyword(s):

General Model ◽

Engineering Application ◽

Hard Work ◽

Deep Foundation ◽

Scientific Methods ◽

Deep Pit ◽

Practical Engineering ◽

Fuzzy Math ◽

Selection Of

Before the construction of the deep pit foundation, we must choose a project. Although there aren't many projects to be chosen as usual, we often feel that it's a very complex and hard work. Actually there is no a mature and general model to use. In this paper, the author attempted to use the theory of fuzzy math to establish a former to select the best project, meanwhile provided two ways to solve how to quantify the qualitative targets and how to determine the weights of the targets. Finally they were confirmed to be useful and successful by a practical engineering application. It is worthily to popularize these scientific methods in construction and management in deep foundation pits.

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Comparative Optimization on the Focusing Methods of Solar-Electric Dish Stirling System

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.236-237.714 ◽

2012 ◽

Vol 236-237 ◽

pp. 714-719

Author(s):

Wei Lan ◽

Bin Wang ◽

Yi Ming Feng

Keyword(s):

Power Systems ◽

High Speed ◽

Power Plants ◽

Solar Power ◽

Thermal Power ◽

Engineering Application ◽

Solar Thermal ◽

Solar Thermal Power ◽

Low Emission ◽

Practical Engineering

Nowadays, the high-speed economic development has caused significant consumption of energy. While the circumstance is getting severer, solar energy is taken as a kind of clean, environmental friendly resource with infinite storage that has aroused a wide public concern. Photovoltaic and solar thermal are two main categories of solar applications. Because of its high conversion efficiency, low emission and flexible installation, dish Stirling solar power technology is more preferable to be used among the solar thermal area. From the view of practical engineering application, this paper illustrates multiple focusing methods of the current dish Stirling solar power systems in detail, and the comparison of these methods are given to analyze their advantages, disadvantages and their application scenarios. It can be used for the future development of dish Stirling solar power technology and applied as a reference for large dish solar thermal power plants’ installations and tests.

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