scholarly journals Reliability Evaluation for Cable-Spring Folding Wing Considering Synchronization of Deployable Mechanism

Actuators ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 99
Author(s):  
Yun Gao ◽  
Ming Hu ◽  
Xiaohong Zhou ◽  
Mingzhong Zhang
Keyword(s):  
Theoretical Model ◽  
Driving Force ◽  
Reliability Evaluation ◽  
Driving Mechanism ◽  
Strong Nonlinearity ◽  
Factors Affecting ◽  
Model And Simulation ◽  
Reliability Method ◽  
Folding Wing ◽  
Deployable Mechanism

The cable-spring folding wing is a novel type of rigid-flexible coupling structure for missiles, which is composed of several sets of deployable mechanisms, with each composed of a wheel-rope transmission system and a parallel spring driving mechanism. The movement of the cable is initiated by the driving force produced by parallel springs, which directly changes the magnitude and the distribution of the driving force. Therefore, the cable-spring folding wing system has the typical characteristics of strong nonlinearity and motion coupling. In addition, each deployable mechanism shares an identical structure, but the distribution of motion parameters is discrepant due to external loads. Asynchronous movement of the cable-spring folding wing will occur and become a significant issue, which is detrimental to the working performance and could even lead to failure. Focusing on these problems, the multi-body dynamics theoretical model and simulation model of deployable mechanism are established, the kinematic and dynamic characteristics of critical components are studied, and the key factors affecting the deployment performance are investigated. A new reliability method with an angular precision control for deployable mechanism is proposed based on the theoretical model. The effectiveness of the proposed model and method is verified by comparing it with the Monte Carlo method. On this basis, the reliability evaluation for cable-spring folding wing, comprehensively considering deployment performance and synchronization, is carried out.

scholarly journals Business Sustainability of Start-Ups Based on Government Support: An Empirical Study of Korean Start-Ups

2019 ◽  
Vol 11 (18) ◽  
pp. 4851 ◽  
Author(s):  
Wooseung Lee ◽  
Boyoung Kim
Keyword(s):  
Market Orientation ◽  
Driving Force ◽  
Government Support ◽  
Flow Experience ◽  
Factors Affecting ◽  
Business Sustainability ◽  
Emerging Nations ◽  
The Government ◽  
Start Ups ◽  
New Jobs

Since the mid-2000s, start-ups have increasingly become the driving force of new jobs and growth engines for advanced countries, and emerging nations are striving to vitalize start-ups through active government support policies. However, approximately 30% of start-ups shut down within two years of their foundation. Accordingly, this study determines the factors affecting the business sustainability of start-ups as based on available government support and provides suggestions to increase the effectiveness of the government-supported projects. This study conducted a survey of 273 start-ups in Korea, and empirically analyzed whether factors such as entrepreneurship, market orientation, and network affected business sustainability by using flow experience and entrepreneurial satisfaction as mediators. The results found that entrepreneurship affected business sustainability with flow experience and entrepreneurial satisfaction as the mediators, while market orientation affected business sustainability using flow experience as the mediator, and network affected business sustainability with entrepreneurial satisfaction as the mediator.

The Fatigue Reliability Evaluation & Improvement of the Single-Arm Subway Current Collector

2012 ◽  
Vol 215-216 ◽  
pp. 826-831 ◽  
Author(s):  
Yu Chen ◽  
Zhi Ming Liu ◽  
Qiang Li
Keyword(s):  
Fatigue Life ◽  
Calculation Result ◽  
Dynamic Stress ◽  
Current Collector ◽  
Reliability Evaluation ◽  
Fatigue Reliability ◽  
Railway Vehicles ◽  
Load Spectra ◽  
Reliability Method

This study developed a fatigue reliability method for evaluating and improving the key parts on railway vehicles, which was applied to real structures. The study involved a type of single-arm current collector, while its contact shoe often collapsed in operation and needs improvements. The dynamic stress data from the actual line was tested and converted to load spectra based on damage consistency rule, and then the fatigue life of the contact shoe structure was achieved. The calculation result comes to correspond to its operation life. Based on the method, an improving plan for the structure was developed under optimizing algorithms.

scholarly journals Internal Force Analysis of Buried-boring Piles in the Yuanzishan Landslide

2020 ◽  
Vol 10 (16) ◽  
pp. 5416 ◽  
Author(s):  
Hao Wang ◽  
Zhiying Lv ◽  
Jianwei Zhang ◽  
Jianwei Yue ◽  
Hongyu Qin ◽  
...  
Keyword(s):  
Driving Force ◽  
Limit Equilibrium ◽  
Bending Moment ◽  
Potential Method ◽  
Internal Force ◽  
Distribution Coefficients ◽  
Factors Affecting ◽  
Pile Diameter ◽  
Unstable Slope ◽  
Internal Forces

The Yuanzishan landslide is an unstable slope in Langzhong County, located in northeast Sichuan province, China. The Guangyuan-Nanchong expressway passes through the front edge of the unstable slope, and subgrade excavation has resulted in slope deformation, which threatens the safety of the highway construction. Emergency landslide control requires reduction of the slope disturbance. This study aims to investigate the use of buried-boring piles as a potential method for emergency landslide control. A simplified calculation method was used for the design of the buried-boring piles, according to the limit equilibrium of the soil and the elastic foundation coefficient method. The measured internal force changes of the pile were compared, in order to determine the distribution coefficients of the driving force. A relationship between the driving force of the shared pile ratio and the buried depth ratios was then established. Furthermore, a variety of factors affecting the internal forces of the buried-boring pile and the lateral reaction of the soil were also studied. The results revealed that (1) there was a quadratic relationship between the driving force of the pile-shared ratio and the sliding depth ratios; (2) the maximum bending moment of the pile increased with an increase in the sliding depth ratio of the pile, following a power law relationship; (3) increasing the buried depth of the pile head reduced the influence of the pile diameter on the maximum internal forces; (4) increasing the pile diameter decreased the maximum lateral reaction of the soil. The buried-boring piles can be used in similarly unstable regions for emergency control of deforming slopes.

scholarly journals Emotional Factors Affecting Knowledge Sharing Intentions in the Context of Competitive Knowledge Network

2020 ◽  
Vol 12 (4) ◽  
pp. 1510
Author(s):  
Hyeon Gyu Jeon ◽  
Kun Chang Lee
Keyword(s):  
Competitive Advantage ◽  
Knowledge Sharing ◽  
Driving Force ◽  
Knowledge Network ◽  
Continuance Intention ◽  
Factors Affecting ◽  
Emotional Factors

This study deals with a competitive knowledge network (CKN) where participants desire to pass their personally important exams, and henceforth want to contribute and seek knowledge about exam-related issues they need to solve. Besides, CKN members are basically competing with each other since they all aim to pass the same exams. Therefore, from the contributor’s perspective, if the advisor fears that his/her advice can be detrimental to his or her own benefits, knowledge sharing (KS) intention within the CKN may be hindered by their expectation of competitive advantage. However, few studies were done about the effects of such fear and a sense of competition on KS continuance intention in the context of CKN. In this sense, our study aims to elucidate the effects of competition and fear on KS continuance intention in a mobile CKN. By using 296 valid questionnaires, we obtained very meaningful conclusions such that competition is a driving force rather than an obstacle to KS among CKN members, and fear also enhances members’ sustainable KS intention.

scholarly journals Tangential motion mechanism and reverse hydrodynamic effects of acoustic platform with nonparallel squeeze film

2018 ◽  
Vol 233 (1) ◽  
pp. 194-204 ◽  
Author(s):  
Wei Bin ◽  
Ran Shaham ◽  
Izhak Bucher ◽  
Jianbin Luo
Keyword(s):  
Theoretical Model ◽  
Travelling Waves ◽  
Tangential Component ◽  
Squeeze Film ◽  
Hydrodynamic Effect ◽  
Driving Mechanism ◽  
Transient Pressure ◽  
Hydrodynamic Effects ◽  
Tangential Directions ◽  
Theoretical Results

In order to explain the reverse hydrodynamic effects on acoustic platform with nonparallel squeeze film, a theoretical model was proposed to evaluate the levitation and movement capacity in this paper. The mechanism of movement and levitation was revealed by the viscous fluid mechanics and dynamic lubrication theory. The transient pressure gradient and steady average velocity were calculated in different deflection angles of nonparallel squeeze film by means of numerical calculation of Reynolds equation. The theoretical results indicated that the platform of nonparallel squeeze film was provided with a bearing and pushing capacity in both normal and tangential directions and it was amazing that the reverse hydrodynamic effects made the levitated plate move into the opposite direction of gravitational tangential component. This proposed theoretical model for acoustic platform with nonparallel squeeze film was different with the original parallel one. Its driving mechanism was the reverse hydrodynamic effect instead of travelling waves. This reverse hydrodynamic effect was proved in the experiments, which could be used in levitation and transport field for precise component in future.

Mechanics of a Graphene Flake Driven by the Stiffness Jump on a Graphene Substrate

2017 ◽  
Vol 84 (8) ◽  
Author(s):  
Hong Gao ◽  
Hongwei Zhang ◽  
Zhengrong Guo ◽  
Tienchong Chang ◽  
Li-Qun Chen
Keyword(s):  
Molecular Dynamics ◽  
Analytical Model ◽  
Driving Force ◽  
Md Simulations ◽  
Driving Mechanism ◽  
Graphene Flake ◽  
Working Temperature ◽  
Directional Motion ◽  
Edge Force ◽  
Motion Behavior

Intrinsic driving mechanism is of particular significance to nanoscale mass delivery and device design. Stiffness gradient-driven directional motion, i.e., nanodurotaxis, provides an intrinsic driving mechanism, but an in-depth understanding of the driving force is still required. Based on molecular dynamics (MD) simulations, here we investigate the motion behavior of a graphene flake on a graphene substrate with a stiffness jump. The effects of the temperature and the stiffness configuration on the driving force are discussed in detail. We show that the driving force is almost totally contributed by the unbalanced edge force and increases with the temperature and the stiffness difference but decreases with the stiffness level. We demonstrate in particular that the shuttle behavior of the flake between two stiffness jumps on the substrate can be controlled by the working temperature and stiffness configuration of the system, and the shuttle frequency can be well predicted by an analytical model. These findings may have general implications for the design of nanodevices driven by stiffness jumps.

The Analysis for the Storage of Difficult Bulk Materials with Central Cone Silo

2012 ◽  
Vol 157-158 ◽  
pp. 154-160
Author(s):  
Wen Jun Meng ◽  
Tian Wei Hong ◽  
Hai Tao Bian
Keyword(s):  
Theoretical Model ◽  
Simulation Model ◽  
Theoretical Calculation ◽  
Bulk Materials ◽  
High Quality ◽  
Model And Simulation ◽  
Central Cone ◽  
Simulation Results

To design high quality and efficiency discharging system, according to the analysis of strength and the study of discharging principle for bulk materials between general silo and central cone silo with discharge arms, their theoretical model and simulation model are established. Based on the theoretical calculation and simulation results, it is proved that the central cone silo which has a rotary discharge arm or discharge arms revolving around the central cone has advantages with discharging the difficult bulk materials, which could efficiently prevent the harmful discharging such as bridging, rat-hole and so on. Controlling the outflow of bulk materials, it is easy to automatically discharge the bulk materials and improve the efficiency of silo system. The result shows that the central cone is practical and the discharging way provides a new program for solving technology problems in discharging the difficult bulk materials.

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