Dynamic Performance of Hydraulic Buffers of Unequal Rating in Series

1981 ◽  
Vol 23 (5) ◽  
pp. 221-224
Author(s):  
M. J. O'Carroll
Keyword(s):  
Dynamic Performance ◽  
Work Load ◽  
High Peak ◽  
Actual Impact ◽  
In Series ◽  
Design Value ◽  
The Impact ◽  
Impact Mass

Standard hydraulic buffers are designed to produce a nearly uniform force so that the work load is equitably shared over the whole stroke. Such designs depend upon the impact mass to be presented to the buffer. If the actual impact mass is greater than the design value then the resulting force has a high peak at closure of the buffer. Occasionally impact conditions have two buffers of different mass-rating in series. This paper shows that such combinations behave like a single uniform-force buffer until one of them closes. The safe impact mass of the combination is established.

scholarly journals REDESAIN JABATAN DAN KEPUASAN KERJA: STUDI PADA GABUNGAN KELOMPOK TANI (GAPOKTAN)

2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Muafi Muafi ◽  
Ari Wijayani
Keyword(s):  
Job Satisfaction ◽  
Survey Research ◽  
Work Load ◽  
Qualitative Approach ◽  
Job Description ◽  
The Government ◽  
Load Handling ◽  
Job Specification ◽  
The Impact ◽  
Work Method

<p>The purpose of this study is to understand the impact of the need to redesign the position of Gapoktan’s management towards job satisfaction. This research is a survey research using qualitative approach. The data were collected using interviews, photos, and notes in the field. Populations in this research are stakeholders (Gapoktan committee, farmers, government) who also become a key participant in Hargobinangun, Kaliurang Sleman Daerah istimewa Yogyakarta. The Gapoktan committee’s participant is 5 person, the government is 3 person, and farmers group is 4 person. The result conclude that a position can be redesigned if the job in that position was used to improve the work method, minimize failure and mistakes, eliminate the work load handling that is unnecessary and work duplication, reduce the fatigue, improve the responsibility, and eventually can increase job satisfaction of the management. All of that can be analyzed by job description and job specification which attached to of each management so that eventually the job satisfaction of the management can be improved.</p>

scholarly journals The Impact of Agile Transformations on Organizational Performance: A Survey of Teams, Programs and Portfolios

2021 ◽  
pp. 86-102
Author(s):  
Christoph Johann Stettina ◽  
Victor van Els ◽  
Job Croonenberg ◽  
Joost Visser
Keyword(s):  
Organizational Performance ◽  
Employee Satisfaction ◽  
International Survey ◽  
Organizational Benefits ◽  
Actual Impact ◽  
The Impact ◽  
Larger Sample ◽  
Insight Into

AbstractWhile many organizations embark on agile transformations, they can lack insight into the actual impact of these transformations across organizational layers. In this paper, we collect new and study existing evidence on the impact of agile transformations on organizational performance across teams, programs and portfolios. We conducted an international survey collecting the perceptions of agile coaches, transformation leads and other relevant roles, and we correlated levels of agile maturity to the perceptions on dimensions of organizational performance. Based on 134 responses from 29 countries across 16 industries, (1) we consolidated understanding of the benefits of agile transformations based on prior evidence and our data from a more diverse and larger sample, (2) we identified the dimensions impacted by agile transformations as being productivity, responsiveness, quality, workflow health and employee satisfaction & engagement and (3) we traced specific benefits on those dimensions to individual organizational layers of teams, programs and portfolios, showing the magnitude of impact of each dimension per layer. Overall, we can conclude that agile transformations have a variety of strong organizational benefits. This aggregated evidence allows reflection on transformation trends, but also enables organizations to optimize their agile transformation efforts.

Numerical analysis of the dynamic performance of aerostatic thrust bearings with different restrictors

2018 ◽  
Vol 233 (3) ◽  
pp. 406-423 ◽  
Author(s):  
Hailong Cui ◽  
Yang Wang ◽  
Xiaobin Yue ◽  
Yifei Li ◽  
Zhengyi Jiang
Keyword(s):  
Load Capacity ◽  
Dynamic Stiffness ◽  
Dynamic Performance ◽  
Dynamic Mesh ◽  
Eccentricity Ratio ◽  
Thrust Bearings ◽  
Stiffness And Damping Coefficient ◽  
Stiffness And Damping ◽  
The Impact ◽  
The Relationship

This study utilizes a dynamic mesh technology to investigate the dynamic performance of aerostatic thrust bearings with orifice restrictor, multiple restrictors, and porous restrictor. An experiment, which investigates the bearing static load capacity, was carried out to verify the calculation accuracy of dynamic mesh technology. Further, the impact of incentive amplitude, incentive frequency, axial eccentricity ratio, and non-flatness on the bearing dynamic performance was also studied. The results show incentive amplitude effect can be ignored at the condition of amplitude less than 5% film thickness, while the relationship between dynamic characteristics and incentive frequency presented a strong nonlinear relationship in the whole frequency range. The change law of dynamic stiffness and damping coefficient for porous restrictor was quite different from orifice restrictor and multiple restrictors. The bearing dynamic performance increased significantly with the growth of axial eccentricity ratio, and the surface non-flatness enhanced dynamic performance of aerostatic thrust bearings.

A novel model-based robust control design for collaborative robot joint module

2022 ◽  
pp. 095440622110547
Author(s):  
ShengChao Zhen ◽  
WangXu Cui ◽  
XiaoLi Liu ◽  
GuanJun Meng ◽  
Ye-Hwa Chen
Keyword(s):  
Numerical Simulation ◽  
Robust Control ◽  
Trajectory Tracking ◽  
Dynamic Performance ◽  
Dynamic Control ◽  
Robot System ◽  
Excellent Control ◽  
Robust Control Design ◽  
The Impact ◽  
Collaborative Robot

In order to reduce the impact of load and system parameter changes on the dynamic performance of collaborative robot joint module, a novel robust control algorithm is proposed in this paper to solve the problem of dynamic control of collaborative robot joint module trajectory tracking. The controller is composed of two parts: one is a nominal control term designed based on the dynamical model, aiming to stabilize the nominal robot system; the other is a robust control term based on the Lyapunov method, aiming to eliminate the influence of uncertainty on tracking performance, where the uncertainties include nonlinear friction, parameter uncertainty, and external disturbances. The Lyapunov minimax method is adopted to prove that the system is uniformly bounded and uniformly ultimately bounded. We performed numerical simulation and experimental validation based on an actual collaborative robot joint module experimental platform and the rapid controller prototype cSPACE. The numerical simulation and experimental results show that the controller has excellent control performance for the collaborative robot joint module and provides more accurate trajectory tracking under the influence of uncertainties.

Modeling and Analysis of Single Hydraulic Props in Coal Mines

2016 ◽  
Vol 693 ◽  
pp. 364-372
Author(s):  
Tao He ◽  
Cao Feng Yu ◽  
Xiao Lei Wu ◽  
Hai Shun Deng
Keyword(s):  
Support System ◽  
Safety Valve ◽  
Impact Load ◽  
Dynamic Performance ◽  
Core Stability ◽  
Mine Safety ◽  
Dead Volume ◽  
Modeling And Analysis ◽  
Hydraulic Prop ◽  
The Impact

This research is focused on dynamic performance of water hydraulic single hydraulic prop, the mathematical and AMESim model of single hydraulic prop are established. And the drop hammer is introduced to simulate the impact load of the surrounding rock acting on the prop. The performance parameters of prop retract displacement and cavity pressure are used as the research objects. The working process of single hydraulic prop is reproduced by the simulation. And the influence of safety valve parameters on the support system is analyzed. The results show that: increasing maximal valve core stroke and dead volume or reducing valve damping hole diameter can improve the support performance of the single hydraulic prop. But the influence of equivalent damping has two sides. For support system, decrease damping can improve the support performance, but for the safety valve, reduce the damping make the valve core stability decline. In addition, the pressure overshoot of the optimized system is 18.3%, adjusting time is 0.5s and the retract displacement is 10mm. The dynamic performances meet the technology requirements of the coal mine safety production of China.

Controlling bridge vibrations using a viscoelastic waveguide absorber

2017 ◽  
Vol 232 (4) ◽  
pp. 1088-1102 ◽  
Author(s):  
Caiyou Zhao ◽  
Ping Wang
Keyword(s):  
Energy Consumption ◽  
Dynamic Performance ◽  
Railway Track ◽  
Favourable Effect ◽  
Railway Bridges ◽  
Vibration Absorption ◽  
Parameter Configuration ◽  
Bridge Vibrations ◽  
The Impact ◽  
Track Slab

The study aims to mitigate the impact of structure-borne noise from existing elevated railway bridges on residents living along the line. In the study, a viscoelastic waveguide absorber mounted on a track slab was proposed based on waveguide vibration absorption techniques by proceeding from the vibration transmitting path and using the track slab as the carrier. First, a dynamic model for the slab-mounted viscoelastic waveguide absorber was constructed, in which a vibration equation was derived and an energy consumption mechanism was obtained. Then, a Chinese railway track style II (CRTS II) ballastless track slab most widely used in Chinese elevated railways was modelled as the primary vibration system, on which an experimental modal analysis was performed. Additionally, a parameterized analysis was performed on the dynamic performance of the slab-mounted viscoelastic waveguide absorber based on the vibration absorption and energy consumption mechanism of the absorber to determine the optimum parameter configuration for the dissipater. Furthermore, the most suitable installation positions for the energy waveguide links were defined using a response surface method. Finally, a bridge vibration response control effectiveness under train loads was also investigated, and it indicated that the waveguide absorbers had a favourable effect in reducing the vibration and structure-borne noise from the elevated railway bridge.

Empirical Optimization of High Density Plate-Fin Heat Sink for Constant Pumping Power in Low Profile Cooling Application

2005 ◽  
Author(s):  
Kazuaki Yazawa ◽  
Tatsuro Yoshida ◽  
Shinji Nakagawa ◽  
Masaru Ishizuka
Keyword(s):  
Fluid Dynamic ◽  
Dynamic Performance ◽  
High Heat ◽  
Heat Sinks ◽  
High Heat Flux ◽  
Pumping Power ◽  
Low Profile ◽  
Data Points ◽  
Narrow Space ◽  
The Impact

Since the VLSI processors are increasing power in accordance with exponential law, cooling solutions for such as personal computers have been evolving for over a decade. Recent heat sinks are designed with high dense fins and low profile to adapt to a high heat flux source within a slim enclosure. To achieve such compact cooling solution, thin fin and small gap is desirable. In addition, the pumping power is also limited by the allowable narrow space for fans. Thus it is important to minimize the thermal resistance for given pumping power that we define the optimum. Due to the lack of literatures on topic of low profile and high dense fins experiments, an apparatus was specially built to measure the thermal and fluid dynamic performance at the same time. Since such a high dense fin arrangement requires extra space on the sides by manufacturing reasons, the impact of bypass flow needs to be considered. The experiments are carefully carried out and the results are precisely compared with numerical analysis. The numerical model aiming to find the optimum for given pumping power is discussed with extrapolating the data points. This report is concluded with the best configuration of plate fins of low profile heat sinks for a given fan performance.

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