scholarly journals Experimental Investigation and Optimization Design of Multi-Support Pipeline System

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Xiantao Zhang ◽  
Wei Liu ◽  
Yamei Zhang ◽  
Yujie Zhao
Keyword(s):  
Natural Frequency ◽  
Vibration Frequency ◽  
Installation Space ◽  
Pipeline System ◽  
Test Results ◽  
Frequency Sweep ◽  
Analysis And Design ◽  
Engine Vibration ◽  
Aero Engine ◽  
Dynamic Frequency

AbstractThe design of aircraft hydraulic pipeline system is limited by many factors, such as the integrity of aviation structure or narrow installation space, so the limited clamp support position should be considered. This paper studied the frequency adjustment and dynamic responses reduction of the multi-support pipeline system through experiment and numerical simulation. To avoid the resonance of pipeline system, we proposed two different optimization programs, one was to avoid aero-engine working range, and another was to avoid aircraft hydraulic pump pulsation range. An optimization method was introduced in this paper to obtain the optimal clamp position. The experiments were introduced to validate the optimization results, and the theoretical optimization results can agree well with the test. With regard to avoiding the aero-engine vibration frequency, the test results revealed that the first natural frequency was far from the aero-engine vibration frequency. And the dynamic frequency sweep results showed that no resonance occurred on the pipeline in the engine vibration frequency range after optimization. Additionally, with regard to avoiding the pump vibration frequency, the test results revealed that natural frequencies have been adjusted and far from the pump vibration frequency. And the dynamic frequency sweep results showed that pipeline under optimal clamp position cannot lead to resonance. The sensitivity analysis results revealed the changing relationships between different clamp position and natural frequency. This study can provide helpful guidance on the analysis and design of practical aircraft pipeline.

Laboratory Tests Study on the Power Dissipation Characteristics of Conductor Self-Damping and Aeolian Vibration Dampers

2010 ◽  
Vol 29-32 ◽  
pp. 2290-2295 ◽  
Author(s):  
Yuan Kun Chen ◽  
Li Li ◽  
Kun Ye ◽  
Peng Yin
Keyword(s):  
Transmission Line ◽  
Natural Frequency ◽  
Vibration Frequency ◽  
Power Dissipation ◽  
Laboratory Tests ◽  
Theoretical Method ◽  
Test Results ◽  
Vibration Effect ◽  
Aeolian Vibration ◽  
Line Engineering

In this paper, laboratory tests on conductor aeolian vibration were designed and carried out, through which the power dissipation characteristics of conductor self-damping and wire dampers(bretelles) were investigated. In addition, the theoretical method was established to estimate the power dissipated by wire damper. The results show that conductor tension and vibration frequency have great influences on its self-damping property; furthermore, the results present that the natural frequency of wire damper is related with its length and the length of wire damper has significant impact on its anti-vibration effect. The theoretical method for calculating the power dissipated by wire damper was verified to be reliable by the test results. These conclusions can provide references for the research and anti-vibration design of transmission line engineering.

Investigating the vibrational behaviour of a rotating two-blade propeller by using a self-tracking method

2018 ◽  
Vol 233 (3) ◽  
pp. 835-847 ◽  
Author(s):  
Mohammad-Reza Ashory ◽  
Farhad Talebi ◽  
Heydar R Ghadikolaei ◽  
Morad Karimpour
Keyword(s):  
Natural Frequency ◽  
Measurement Errors ◽  
Mode Shapes ◽  
Model Parameters ◽  
Test Results ◽  
Modal Assurance Criterion ◽  
Tracking Method ◽  
Strong Resemblance ◽  
Test Scenarios ◽  
Good Agreement

This study investigated the vibrational behaviour of a rotating two-blade propeller at different rotational speeds by using self-tracking laser Doppler vibrometry. Given that a self-tracking method necessitates the accurate adjustment of test setups to reduce measurement errors, a test table with sufficient rigidity was designed and built to enable the adjustment and repair of test components. The results of the self-tracking test on the rotating propeller indicated an increase in natural frequency and a decrease in the amplitude of normalized mode shapes as rotational speed increases. To assess the test results, a numerical model created in ABAQUS was used. The model parameters were tuned in such a way that the natural frequency and associated mode shapes were in good agreement with those derived using a hammer test on a stationary propeller. The mode shapes obtained from the hammer test and the numerical (ABAQUS) modelling were compared using the modal assurance criterion. The examination indicated a strong resemblance between the hammer test results and the numerical findings. Hence, the model can be employed to determine the other mechanical properties of two-blade propellers in test scenarios.

Design of Six Freedom Vibration Acquisition System for Military Vehicle

2012 ◽  
Vol 430-432 ◽  
pp. 1866-1870
Author(s):  
Zhi Xiong Zhu ◽  
Shi Shun Zhu ◽  
Guo Jun Wang ◽  
Yan Zhu
Keyword(s):  
Reference System ◽  
Vibration Spectrum ◽  
Object Oriented ◽  
Linear Acceleration ◽  
Test Results ◽  
Collection System ◽  
Analysis And Design ◽  
Design And Implementation ◽  
Military Vehicle ◽  
Collection Data

Design and implementation of six freedom transportation vibration spectrum collection system is presented in this paper. The Attitude and Heading Reference System (AHRS) is used to capture signals including x, y, z, direction linear acceleration, angular rates around Z-axis and pitch, roll degree. The software’s architecture and modules for host computer is designed with object-oriented analysis and design techniques, and the software is implemented with VC++6.0. The test results show that the system was able to collect vehicular vibration information on time and the collection data was replayed on the vibration platform.

scholarly journals Performance research and safety verification of compound structure air spring

2020 ◽  
Vol 12 (12) ◽  
pp. 168781402097479
Author(s):  
Lihang Yin ◽  
Wei Xu ◽  
Zechao Hu ◽  
Yuanchao Zhang ◽  
Chuang Li
Keyword(s):  
Natural Frequency ◽  
Dynamic Stiffness ◽  
Lateral Stiffness ◽  
Test Results ◽  
Air Spring ◽  
Compound Structure ◽  
Static And Dynamic Characteristics ◽  
Vertical Stiffness ◽  
Safety And Reliability ◽  
Performance Research

To further reduce the vertical stiffness of the air spring, appropriately reduce its lateral stiffness to attenuate the transmission of vibration along the lateral and longitudinal directions, a compound structure air spring (CSAS) was designed. It is a laminated structure with a hard elastic layer at the lower end of the original air spring. Prototypes of the air spring and the CSAS were produced, then related static and dynamic characteristics tests were conducted. Compared with the test results of the air spring, it can be found that under the same air pressure, the bearing capacity of the CSAS is decreased slightly; under rated load, the vertical static/dynamic stiffness and natural frequency is decreased slightly, and the lateral static/dynamic stiffness is decrease significantly. Furthermore, the CSAS was subjected to the safety and reliability tests, and its performance was stable without damage. This article expands the stiffness range of the air spring, and provides a new idea for the design of the air spring with low lateral to vertical stiffness ratio and low natural frequency.

Frequency Characteristics Analysis of Micro-Displacement Structure with Parallel Flexure Hinges

2016 ◽  
Vol 693 ◽  
pp. 141-145
Author(s):  
Jie Qiong Lin ◽  
Ming Ming Lu ◽  
Xiao Qin Zhou ◽  
Qiang Liu
Keyword(s):  
Natural Frequency ◽  
Structure Design ◽  
Frequency Characteristics ◽  
Test Results ◽  
Structure Parameter ◽  
Dynamics Modeling ◽  
Displacement Structure ◽  
Flexure Hinges ◽  
Modeling Analysis ◽  
Characteristics Analysis

Flexure hinges based micro-displacement structure has been widely used for micro-precision machinery, and the natural frequency characteristics analysis is one of the most important elements in the structure design. In this paper, natural frequency characteristics analysis of a micro-displacement structure with parallel flexible hinges is presented. The effects of each structure parameter to the natural frequency of the micro-displacement structure are simulation by dynamics modeling. The parameters can be divided into three categories, namely, parallel flexure hinges parameter, micro-displacement structure parameter and material parameter. Two micro-displacement structures using common materials are machined for frequency test. The test results of two micro-displacement structure verified the modeling analysis, and the natural frequency characteristics analysis in this paper can be referenced in micro-displacement structure design.

Analysis and Design Recommendations for the Collapse of a Concrete Silo

2011 ◽  
Vol 250-253 ◽  
pp. 2877-2880 ◽  
Author(s):  
Guang Lin Yuan ◽  
Lu Dan Tian
Keyword(s):  
Reinforced Concrete ◽  
Concrete Strength ◽  
Structure Design ◽  
Test Results ◽  
Reinforcing Bars ◽  
Design Recommendations ◽  
Analysis And Design ◽  
The Future ◽  
Design And Construction

Accidents of the cement manufacturers’ reinforced concrete silo structures frequently occurred currently in China, because of quality problems, causing enormous losses. The collapse status of a cement raw meal silo is investigated. Combined with the test results of the location and spacing of silo wall’s reinforcing bars, concrete strength, cracks and defects, the reasons for collapse of silo wall are analyzed and design recommendations for concrete silo structures are made. This can give reference to reinforced concrete silo structure design and construction in the future.

Thermal Performance Improvement of a Heat Sink With Piezoelectric Vibrating Fins

2010 ◽  
Author(s):  
Hee Seung Park ◽  
Sung Jin Kim
Keyword(s):  
Natural Frequency ◽  
Performance Improvement ◽  
Thermal Performance ◽  
Vibration Frequency ◽  
Heat Sink ◽  
Vibration Amplitude ◽  
Piezoelectric Actuators ◽  
Convection Heat ◽  
Heat Transfer Characteristics ◽  
Heat Sink Temperature

A heat sink with piezoelectric vibrating fins is developed through attaching piezoelectric actuators to the fins of a heat sink, and the heat transfer characteristics of the heat sink are experimentally investigated. Thermal performance improvement of the heat sink by the vibration of the fins is observed compared to the thermal performance of a natural convection heat sink with static fins under a fixed heat sink geometry condition. The thermal performance of the heat sink changes as the vibration amplitude of the fins or the vibration frequency of the fins changes. Particularly, if the vibration frequency of the fins matches up to the natural frequency of the fins, the vibration amplitude is significantly increased by resonance and the thermal performance also increases. The natural frequency of the fins changes with the heat sink temperature because the geometry of the fins changes and the properties of the fins change due to the temperature change.

Effects of Ceramsite Concrete Strength on Natural Frequency Based on ANSYS

2012 ◽  
Vol 204-208 ◽  
pp. 4124-4127
Author(s):  
Hao Qing Wang ◽  
Qiu Kong ◽  
Zhou Ping Yu ◽  
Wei Jun Yang
Keyword(s):  
Natural Frequency ◽  
Seismic Design ◽  
Vibration Frequency ◽  
Concrete Strength ◽  
Reinforcing Steel ◽  
Material Parameters ◽  
Modeling Analysis ◽  
Steel Bar ◽  
Environmental Vibration

By separate modeling analysis based upon ANSYS, SOLID65 unit of the entity is selected to simulate ceramsite concrete, and reinforcing performance is selected to simulate the effect of reinforcing steel bar. The strength on natural frequency’s effects was studied through changing the ansys model’s material parameters of ceramsite concrete. The strength of ceramsite concrete can be determined and applied to the anti-seismic design according to the size of the environmental vibration frequency.

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