scholarly journals Investigation of the Dynamic Performance of a Large-Span Suspension Bridge Influenced by Scouring Based on Vehicle-Bridge Coupled Vibration

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Qingfei Gao ◽  
Biao Wu ◽  
Renzhi Wang ◽  
Jiaqiang Zhang ◽  
Binqiang Guo ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Dynamic Load ◽  
Dynamic Performance ◽  
Dynamic Responses ◽  
Vibration Modes ◽  
Vehicle Speed ◽  
Coupled Vibration ◽  
Erosion Depth ◽  
Dynamic Load Allowance ◽  
Scouring Depth

To study the damage of bridge pile foundations caused by scouring, two damage mechanisms of scouring are proposed in this paper. Considering the vehicle-bridge coupled vibration in terms of two aspects of the scouring depth and erosion depth, the vertical and transversal dynamic characteristics and dynamic responses of the bridge are studied under different cases for the most sensitive vehicle speed. The dynamic characteristics include the 1st and 2nd vibration modes of the vertical and transversal directions of the bridge. The dynamic responses include the vertical and transversal dynamic load allowances and acceleration of the bridge. The souring depth is more sensitive than the erosion depth, and the 2nd vertical mode is most substantially influenced by scouring and erosion. Because of the small value of the natural frequency of the vertical vibration modes, the transversal vibration modes may be more convenient to obtain. The study of the dynamic responses shows that the scouring depth can be represented by the dynamic load allowance in the middle of the span’s section and the erosion depth can be characterized by the dynamic load allowance at the quarter location of the span’s section.

Dynamic Field Performance of Glued Laminated Timber Bridges

2005 ◽  
Vol 1928 (1) ◽  
pp. 154-164
Author(s):  
Jake Bigelow ◽  
Brent Phares ◽  
Terry Wipf ◽  
Mike Ritter ◽  
Doug Wood
Keyword(s):  
Dynamic Load ◽  
Dynamic Performance ◽  
Field Performance ◽  
Performance Data ◽  
Girder Bridges ◽  
Dynamic Field ◽  
Dynamic Load Allowance ◽  
Glued Laminated Timber ◽  
National Programs ◽  
Timber Bridges

To use and develop timber structures in transportation better, the U.S. government implemented several national programs starting in the early 1990s to address the needs of the timber industry. One need was to investigate the dynamic field performance of timber bridges in relation to vehicular loading. The AASHTO load and resistance factor design specifications recommend a dynamic load allowance of 0.165 for timber bridges. To investigate this codified value, research was needed to determine the dynamic characteristics of timber bridges and to study their dynamic performance. To obtain dynamic performance data, five glued laminated girder bridges and four longitudinal glued laminated panel bridges were selected for testing. The testing involved loading the nine structures to obtain dynamic performance data including deflection and acceleration, as well as to assess the overall condition state of the bridges. The nine bridges tested were found to have fundamental frequencies between 5 Hz and 11 Hz as well as a dynamic load allowance of less than 0.25. The bridges found to have dynamic amplifications above specified code values were also found to have physical characteristics (i.e., rough entrances) that likely caused the higher dynamic amplification values.

Effect of Track Geometric Irregularity on Dynamic Characteristics of Gear Transmission in a Locomotive

2017 ◽  
Author(s):  
Tao Zhang ◽  
Zaigang Chen ◽  
Jie Zhang ◽  
Shunqi Sui ◽  
Cheng Pan
Keyword(s):  
Dynamic Characteristics ◽  
Life Prediction ◽  
Dynamic Performance ◽  
Gear Transmission ◽  
Fatigue Life Prediction ◽  
Dynamic Responses ◽  
Mean Square ◽  
Track Irregularity ◽  
Working Performance ◽  
Statistical Indicators

Gear transmission is a key component in locomotive where it delivers the traction or braking forces between the motor and the wheelset. Its working performance has a direct effect on the operating reliability and safety. Therefore, investigation on the dynamic characteristics of the gear transmission in locomotives is very meaningful. In this study, a gear transmission-locomotive-track spatial coupled dynamic model is established based on the classical locomotive-track coupled dynamics and the gear dynamics theory. Based on this model, the dynamic responses of the gear transmission can be analysed under excitations from different track geometrical irregularity, and the dynamic performance of the gear transmission can be obtained. This paper also studies the effect law of the track irregularity on the vibration of the gear transmission by using statistical indicators RMS (Root Mean Square) and PtP (Peak-to-Peak). The results indicate that the track geometrical irregularity has an obvious impact to the dynamic performance of gear transmission. The dynamic response of the gear transmission will increase violently when the locomotive runs on the track in a worse condition. The results are expected to be capable of providing some references for fatigue life prediction and reliability analysis of the gear transmissions in locomotive.

Research on the dynamic characteristics of a 3-DOF parallel tool head

2017 ◽  
Vol 44 (1) ◽  
pp. 28-37 ◽  
Author(s):  
Dong Wang ◽  
Jun Wu ◽  
Liping Wang ◽  
Yuzhe Liu ◽  
Guang Yu
Keyword(s):  
Dynamic Characteristics ◽  
Dynamic Load ◽  
Dynamic Performance ◽  
Tracking Error ◽  
Joint Space ◽  
Time Varying ◽  
Parallel Mechanisms ◽  
Content Type ◽  
Dynamic Index ◽  
Coupling Dynamic

Purpose The purpose of this paper is to describe and evaluate the time-varying and coupling dynamic characteristics of a 3-DOF parallel tool head. Design/methodology/approach From the view of control, a new dynamic index of a 3-DOF parallel tool head is proposed based on the dynamic model in the joint space. This index can reflect the time-varying and coupling dynamic characteristics which are the main characteristics of the parallel mechanisms, and its distribution in the whole workspace is also given. Through comparison of the dynamic load (driving current) of each driving shaft, a series of experiments is designed and carried out on a prototype to validate the effectiveness of the dynamic analysis. The tracking error of each driving shaft has also been taken into consideration. Findings The simulations of the index have the same variation law with the experimental results. The dynamic load of the driving shaft becomes larger with the increase of the dynamic index, and the dynamic performance becomes worse at the same time. Originality/value The main dynamic characteristics of the 3-DOF parallel tool head can be described and evaluated through this work.

scholarly journals Vehicle Ride Comfort Analysis Based on Vehicle-Bridge Coupled Vibration

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yichang Zhang ◽  
Wusheng Li ◽  
Zhe Ji ◽  
Guichun Wang
Keyword(s):  
Rational Design ◽  
Ride Comfort ◽  
Dynamic Balance ◽  
Dynamic Responses ◽  
Ride Quality ◽  
Vehicle Speed ◽  
Coupled Vibration ◽  
Coupling Vibration ◽  
Multiple Vehicles ◽  
Vibration Responses

The study in this paper aims to evaluate the effects of vehicle-bridge coupled vibration on the vehicle ride comfort. The mechanical model of both vehicle and bridge subsystems and the vibration differential equations are established, respectively, based on the principle of dynamic balance and finite element method. The APDL command stream for iterative calculation is compiled on the ANSYS platform. The method to evaluate the vehicle ride comfort is established according to the criteria in ISO2631-1-1997. The vehicle dynamic responses and ride comfort are analyzed considering different pavement levels while multiple vehicles pass through the cable-stayed bridge. The analysis results indicate that the dynamic responses of vehicles decrease with the improvement of pavement roughness, resulting in the vehicle ride comfort to be better; the dynamic responses of vehicles increase with the increment of vehicle speed or the decrement of vehicle gravity, resulting in the vehicle ride comfort to be worse. The present research results can provide an insight into the rational design of bridge structure so as to reduce the vehicle-bridge coupling vibration responses and improve the ride quality of drivers and passengers.

Micro-pressure sensor dynamic performance analysis

Sensor Review ◽  
2014 ◽  
Vol 34 (4) ◽  
pp. 367-373 ◽  
Author(s):  
Bian Tian ◽  
Yulong Zhao ◽  
Zhe Niu ◽  
Jiang Zhuangde
Keyword(s):  
Dynamic Characteristics ◽  
Pressure Sensor ◽  
Dynamic Pressure ◽  
Dynamic Performance ◽  
Pressure Sensors ◽  
Dynamic Responses ◽  
Content Type ◽  
Dynamic Performances ◽  
Traditional Structures ◽  
Dynamic Performance Analysis

Purpose – The purpose of this paper is to report on a piezoresistive pressure sensor for micro-pressure measurement with a cross-beam membrane (CBM) structure. This study analyzes the dynamic characteristics of the proposed device. Design/methodology/approach – This CBM sensor possesses high stiffness and sensitivity, measuring dynamic pressure more effectively in a high-frequency environment compared with other piezoresistive structures. The dynamic characteristics are derived using the finite element method to analyze the dynamic responses of the new structure, including natural frequency and lateral effect performances. The CBM dynamic performances are compared with traditional structures. Findings – The pressure sensor performance was evaluated, and the experimental results indicate that they all exhibit similar dynamic characteristics as the designed model. Compared with traditional structures such as the single island, the CBM proves to be superior in evaluating the dynamic performances of pressure sensors at high frequencies of > 30 kHz. Originality/value – Most studies of this micro pressure sensors attempt to promote the sensitivity or focus on the static performance of pressure sensor with micro gauge. This study is concerned with analyze the dynamic characterism of micro pressure sensor and compared with the traditional structures, that prove the CBM structure has stable dynamic performance and is a better option for measuring dynamic micro pressure in biomedical applications.

Dynamic Characteristics of a Horizontal Milling Machine with Hybrid Guideway Systems

2013 ◽  
Vol 423-426 ◽  
pp. 2127-2131
Author(s):  
Jui Pin Hung ◽  
Wei Chu Lin ◽  
Tzou Lung Luo ◽  
Yu Sheng Lai
Keyword(s):  
Finite Element ◽  
Dynamic Characteristics ◽  
Contact Stiffness ◽  
Dynamic Performance ◽  
Dynamic Compliance ◽  
Element Model ◽  
Dynamic Responses ◽  
Milling Machine ◽  
Feeding Mechanism ◽  
Axis Direction

This study was aimed to investigate dynamic characteristics of a milling machine with horizontal spindle tooling system, which was feed through the linear feeding mechanism combined with the sliding guides and linear roller guide modulus. To predict the dynamic characteristics, we created finite element model of the milling machine with the introduction of the contact stiffness defined at the sliding and rolling interface, respectively. The results of the finite element simulations reveal that linear guides with different preloads greatly affect the dynamic responses of the horizontal spindle tool. The maximum dynamic compliance can be increased by 7.4 % in X-axis direction and increased by 12 % in Y-axis direction, respectively when the linear guides are changed from low to high preload. Overall, current results clearly illustrate that the proposed modeling approach of feeding mechanism can quantify the preload effect of the guideway system on the dynamic performance of a milling machine.

Evaluation for Dynamic Performance of Simple-Continuous Bridge

2011 ◽  
Vol 250-253 ◽  
pp. 1360-1365
Author(s):  
Ke Jian Sheng ◽  
Zong Lin Wang
Keyword(s):  
Vibration Amplitude ◽  
Dynamic Performance ◽  
Influential Factors ◽  
Dynamic Responses ◽  
Coupled Vibration ◽  
Vehicle Model ◽  
Structural Dynamic ◽  
Standard Design ◽  
Dynamic Performances ◽  
Traveling Speed

It is necessary to study the dynamic responses of simple-continuous bridges under traveling vehicles action, which may benefit the improvement of their dynamic performances. According to “Standard Design Drawings” issued by Ministry of Communications of PRC, this paper considers the alterations of span length, decking width and sectional style and the differences of vehicle model and traveling speed, and calculates separately dynamic response of these structures with the “vehicle-bridge coupled vibration program”. As two key influential factors, vibration amplitude and acceleration are applied for the evaluation of structural dynamic performance. The results show that dynamic performance of simple-continuous cored slab bridge is deficiency in some degree.

scholarly journals Coupled vibration of piezoelectric-based propeller blades for a novel unmanned underwater vehicle

2020 ◽  
Vol 12 (4) ◽  
pp. 168781402091658
Author(s):  
Daohua Lu ◽  
Chong Li ◽  
Jia Wang ◽  
Jiwen Fang
Keyword(s):  
Dynamic Performance ◽  
Design Procedure ◽  
Simulation Method ◽  
Underwater Vehicle ◽  
Dynamic Responses ◽  
Matlab Simulation ◽  
Coupled Vibration ◽  
Unmanned Underwater Vehicle ◽  
Lagrange’S Equation ◽  
Propeller Blades

To reduce the vibration of the propeller blades, a novel unmanned underwater vehicle–integrated piezoelectric additive manufacturing technology is proposed in this article. The operating principle and design procedure of the proposed unmanned underwater vehicle are illustrated. Utilizing piezoelectric dynamic theory and Lagrange’s equation, the coupled vibration equations of piezoelectric-propeller blades system under complex excitation are established. Applying MATLAB simulation method, the dynamic responses of the coupled blades under external and piezoelectric excitation are investigated. With finite-element method software, the correctness of the theoretical analysis is verified. Results show that the maximum amplitudes of the propeller blades are distributed at the end of the blades, thus placing the piezoelectric layers at the terminal blades can minimize the vibration of the propeller blades. Meanwhile, the vibration amplitudes of propeller blades can be reduced by more than 70% by applying piezoelectric coating. These results can be used to reduce the vibration and improve the dynamic performance during the unmanned underwater vehicle operating.

Comparison on General Track Spectrum for Chinese Main Railway Lines and Track Spectrum of American Railway Lines

2011 ◽  
Vol 250-253 ◽  
pp. 3822-3826 ◽  
Author(s):  
Xian Mai Chen ◽  
Xia Xin Tao ◽  
Gao Hang Cui ◽  
Fu Tong Wang
Keyword(s):  
Dynamic Performance ◽  
Dynamic Responses ◽  
Wave Band ◽  
Wheel Load ◽  
Railway Line ◽  
Acceleration Rate ◽  
Time Histories ◽  
Railway System ◽  
Dynamic Performances ◽  
Track Irregularity

The general track spectrum of Chinese main railway lines (ChinaRLS) and the track spectrum of American railway lines (AmericaRLS) are compared in terms of character of frequency domain, statistical property of time domain samples and dynamic performance. That the wavelength range of the ChinaRLS, which is characterized by the three levels according to the class of railway line, is less than AmericaRLS at common wave band of 1~50m is calculated. Simultaneously, the mean square values of two kinds of track spectra are provided at the detrimental wave bands of 5~10m, 10~20m, and so on. The time-histories of ChinaRLS and AmericaRLS are simulated according to the trigonometric method, and the digital statistical nature of simulated time samples is analyzed. With inputting the two kinds of time-histories into the vehicle-railway system, the comparative analysis of the two kinds of dynamic performances for ChinaRLS and AmericaRLS is done in terms of car body acceleration, rate of wheel load reduction, wheel/rail force, and the dynamic responses of track structure. The result shows that ChinaRLS can characterize the feature of the Chinese track irregularity better than AmericaRLS, the track irregularity with the ChinaRLS of 200km/h is superior to the AmericaRLS, and the track irregularity with the ChinaRLS of 160km/h corresponds to with the sixth of AmericaRLS.

scholarly journals Lane Departure Warning Estimation Using Yaw Acceleration

2020 ◽  
Vol 11 (1) ◽  
pp. 102-111
Author(s):  
Em Poh Ping ◽  
J. Hossen ◽  
Wong Eng Kiong
Keyword(s):  
Vehicle Dynamics ◽  
Dynamic Responses ◽  
Dynamics Simulation ◽  
Steering Wheel ◽  
Mathematical Representation ◽  
Vehicle Speed ◽  
Lane Departure Warning ◽  
Model Based ◽  
Lane Departure ◽  
Proposed Model

AbstractLane departure collisions have contributed to the traffic accidents that cause millions of injuries and tens of thousands of casualties per year worldwide. Due to vision-based lane departure warning limitation from environmental conditions that affecting system performance, a model-based vehicle dynamics framework is proposed for estimating the lane departure event by using vehicle dynamics responses. The model-based vehicle dynamics framework mainly consists of a mathematical representation of 9-degree of freedom system, which permitted to pitch, roll, and yaw as well as to move in lateral and longitudinal directions with each tire allowed to rotate on its axle axis. The proposed model-based vehicle dynamics framework is created with a ride model, Calspan tire model, handling model, slip angle, and longitudinal slip subsystems. The vehicle speed and steering wheel angle datasets are used as the input in vehicle dynamics simulation for predicting lane departure event. Among the simulated vehicle dynamic responses, the yaw acceleration response is observed to provide earlier insight in predicting the future lane departure event compared to other vehicle dynamics responses. The proposed model-based vehicle dynamics framework had shown the effectiveness in estimating lane departure using steering wheel angle and vehicle speed inputs.

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