Testing and Analysis of Fasteners

2021 ◽  
Vol 9 (10) ◽  
pp. 235-243
Author(s):  
Omkar Adhikari
Keyword(s):  
Biaxial Loading ◽  
Experimental Testing ◽  
Axial Loading ◽  
Control Valve ◽  
Pneumatic Cylinder ◽  
Flow Control Valve ◽  
Mode Of Failure ◽  
Long Time ◽  
Upward Direction ◽  
Over Time

Abstract: By considering the tightening process, the experimental testing will be conducted to explore the mechanism of bolt selfloosening under biaxial loading. The most common mode of failure is overloading: Operating forces of the application produce loads that exceed the clamp load, causing the joint to loosen over time or fail catastrophically. Over torque might cause failure by damaging the threads and deforming the fastener, though this can happen over a very long time. Also, the bolts may fail under fatigue. The components used in the system are bolts, pneumatic cylinder and flow control valve. The pneumatic cylinder is actuated with the help of compressor. The flow of air in the cylinder will be controlled with the help of pneumatic cylinder which will be acted on the bolts in two directions that is from downward & upward direction. This means the load will be tensile and shearing load. The bolts are attached to the plates. Because of actuation of the pneumatic cylinder the bolts will become loose. These bolts will be tested by using biaxial loading. The result & conclusion was drawn after the experimental testing. Keywords: Bi-axial Loading, Fasteners, Bolt Loosening, Residual Torque, Fastener Overloading

scholarly journals Speed Control of Pneumatic Cylinder using Particle-Excitation Flow Control Valve

2015 ◽  
Vol 46 (2) ◽  
pp. 7-13 ◽  
Author(s):  
Daisuke HIROOKA ◽  
Tomomi YAMAGUCHI ◽  
Naomichi FURUSHIRO ◽  
Koichi SUZUMORI ◽  
Takefumi KANDA
Keyword(s):  
Flow Control ◽  
Control Valve ◽  
Speed Control ◽  
Pneumatic Cylinder ◽  
Flow Control Valve

A Multi-modes Flow Control Valve for Simplifying the Driving System of Pneumatic Soft Robots

2020 ◽  
pp. 1-1
Author(s):  
Yang Yang ◽  
Yongjian Zhao ◽  
Songyi Zhong ◽  
Yan Peng ◽  
Yi Yang ◽  
...  
Keyword(s):  
Flow Control ◽  
Control Valve ◽  
Flow Control Valve ◽  
Soft Robots ◽  
Driving System

scholarly journals Predicting Mixture Effects over Time with Toxicokinetic–Toxicodynamic Models (GUTS): Assumptions, Experimental Testing, and Predictive Power

2021 ◽  
Vol 55 (4) ◽  
pp. 2430-2439
Author(s):  
Sylvain Bart ◽  
Tjalling Jager ◽  
Alex Robinson ◽  
Elma Lahive ◽  
David J. Spurgeon ◽  
...  
Keyword(s):  
Predictive Power ◽  
Experimental Testing ◽  
Mixture Effects ◽  
Over Time

scholarly journals Dynamics of life expectancy and life span equality

2020 ◽  
Vol 117 (10) ◽  
pp. 5250-5259 ◽  
Author(s):  
José Manuel Aburto ◽  
Francisco Villavicencio ◽  
Ugofilippo Basellini ◽  
Søren Kjærgaard ◽  
James W. Vaupel
Keyword(s):  
Life Expectancy ◽  
Life Span ◽  
Health Policies ◽  
Public Health Policies ◽  
Dynamic Relationship ◽  
Mortality Increase ◽  
Long Time ◽  
Underlying Causes ◽  
The Relationship ◽  
Over Time

As people live longer, ages at death are becoming more similar. This dual advance over the last two centuries, a central aim of public health policies, is a major achievement of modern civilization. Some recent exceptions to the joint rise of life expectancy and life span equality, however, make it difficult to determine the underlying causes of this relationship. Here, we develop a unifying framework to study life expectancy and life span equality over time, relying on concepts about the pace and shape of aging. We study the dynamic relationship between life expectancy and life span equality with reliable data from the Human Mortality Database for 49 countries and regions with emphasis on the long time series from Sweden. Our results demonstrate that both changes in life expectancy and life span equality are weighted totals of rates of progress in reducing mortality. This finding holds for three different measures of the variability of life spans. The weights evolve over time and indicate the ages at which reductions in mortality increase life expectancy and life span equality: the more progress at the youngest ages, the tighter the relationship. The link between life expectancy and life span equality is especially strong when life expectancy is less than 70 y. In recent decades, life expectancy and life span equality have occasionally moved in opposite directions due to larger improvements in mortality at older ages or a slowdown in declines in midlife mortality. Saving lives at ages below life expectancy is the key to increasing both life expectancy and life span equality.

Pattern Recognition Approach to Fault Diagnosis in the DAMADICS Benchmark Flow Control Valve

2003 ◽  
Vol 36 (5) ◽  
pp. 861-866 ◽  
Author(s):  
A. Marciniak ◽  
C.D. Bocăială ◽  
R. Louro ◽  
J. Sa da Costa ◽  
J. Korbicz
Keyword(s):  
Pattern Recognition ◽  
Fault Diagnosis ◽  
Flow Control ◽  
Control Valve ◽  
Flow Control Valve ◽  
Pattern Recognition Approach

Design and evaluation of orifice arrangement for particle-excitation flow control valve

2011 ◽  
Vol 171 (2) ◽  
pp. 283-291 ◽  
Author(s):  
Daisuke Hirooka ◽  
Koichi Suzumori ◽  
Takefumi Kanda
Keyword(s):  
Flow Control ◽  
Control Valve ◽  
Flow Control Valve

L1 Adaptive Control for Aircraft Air Management System Pressure-Regulating Bleed Valve

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
John Cooper ◽  
Chengyu Cao ◽  
Jiong Tang
Keyword(s):  
Management System ◽  
Control Valve ◽  
Pressure Control ◽  
Adaptive Controller ◽  
System Model ◽  
Flow Control Valve ◽  
L1 Adaptive Control ◽  
System Pressure ◽  
L1 Adaptive Controller ◽  
Linear Controllers

This paper presents an L1 adaptive controller for pressure control using an engine bleed valve in an aircraft air management system (AMS). The air management system is composed of two pressure-regulating bleed valves, a temperature control valve, a flow control valve, and a heat exchanger/precooler. Valve hysteresis due to backlash and dry friction is included in the system model. The nonlinearities involved in the system cause oscillations under linear controllers, which decrease component life. This paper is the unique in the consideration of these uncertainties for control design. This paper presents simulation results using the adaptive controller and compares them to those using a proportional–integral (PI) controller.

QUALITY AND SAFETY - TWO SIDES OF THE SAME COIN IN HOSPITALITY AND TOURISM

2009 ◽  
Vol 15 (2) ◽  
pp. 193-204
Author(s):  
Anders Steene
Keyword(s):  
Quality And Safety ◽  
Quality Aspects ◽  
Long Time ◽  
Hospitality And Tourism ◽  
Two Sides ◽  
Over Time

This paper will discuss some methodical aspects in doing research in the field of hospitality and tourism. Quality aspects have been dominant subjects for a long time in the industry, safety and security aspects were more or less not on the agenda in the early 90-ies. According to how society has developed, the experience of risk and danger has changed in the society over time and nowadays both safety and security as well as quality aspects has become important elements in the tourism products. The question is, if those two different approaches can be used as mutual methods.

Design and Analysis of a Flow-Control Valve With Controllable Pressure Compensation Capability for Mobile Machinery

2021 ◽  
Author(s):  
Bo Wang ◽  
Yunwei Li ◽  
Long Quan ◽  
Lianpeng Xia
Keyword(s):  
Pressure Drop ◽  
Flow Control ◽  
Pressure Difference ◽  
Control Valve ◽  
Flow Control Valve ◽  
Continuous Control ◽  
Small Flow ◽  
Pressure Compensation ◽  
Force Compensation ◽  
Control Accuracy

Abstract There are the problems in the traditional pressure-compensation flow-control valve, such as low flow control accuracy, small flow control difficulty, and limited flow range. For this, a method of continuous control pressure drop Δprated (i.e. the pressure drop across the main throttling orifice) to control flow-control valve flow is proposed. The precise control of small flow is realized by reducing the pressure drop Δprated and the flow range is amplified by increasing pressure drop Δprated. At the same time, it can also compensate the flow force to improve the flow control accuracy by regulating the pressure drop Δprated. In the research, the flow-control valve with controllable pressure compensation capability (FVCP) was designed firstly and theoretically analyzed. Then the sub-model model of PPRV and the joint simulation model of the FVCP were established and verified through experiments. Finally, the continuous control characteristics of pressure drop Δprated, the flow characteristics, and flow force compensation were studied. The research results demonstrate that, compared with the traditional flow-control valve, the designed FVCP can adjust the compensation pressure difference in the range of 0∼3.4 MPa in real-time. And the flow rate can be altered within the range of 44%∼136% of the rated flow. By adjusting the compensation pressure difference to compensate the flow force, the flow control accuracy of the multi-way valve is improved, and the flow force compensation effect is obvious.

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