Statistics Analysis of the Bridge Dynamic Response in the Survey of Expressway Traffic Loads

2011 ◽  
Vol 250-253 ◽  
pp. 1633-1637
Author(s):  
Tao Wang ◽  
Wan Shui Han
Keyword(s):  
Dynamic Response ◽  
Rapid Development ◽  
Bridge Engineering ◽  
Dynamic Responses ◽  
Critical Parameters ◽  
Dynamic Strain ◽  
Statistics Analysis ◽  
Coupling Vibration ◽  
Traffic Lane ◽  
Traffic Loads

Nowadays, with the rapid development of the traffic infrastructure construction and the growing of the traffic flowing and speed, the vehicle-bridge coupling vibration research has become the focus of the bridge engineering study. The dynamic response of the bridge under the traffic flowing is one of vital parameters for the vehicle-bridge coupling vibration analysis. In this paper, a methodology, employing the radar speed gun, the video recorder, and the dynamic strain tester in combination with manually recording is used to continuously and detailed investigate the traffic loads on the expressway bridge within 24 hours a day. With this approach introduced by this paper, all the critical parameters, such as the vehicle type, speed, traffic lane, the arriving time of the traffic and the bridge-vehicle dynamic interaction are all recorded. In this investigation, firstly the dynamic responses of 8 pieces of beams of the bridge under 5650 individual vehicles driving through the bridge are recorded, secondly statistics analysis are made for the record of each beam, and finally the space-time distribution laws of the dynamic response of the bridge under the traffic flowing are studied extensively. The result of this study could provide helpful theoretic guidance and supporting data for the vehicle-bridge coupling vibration research.

Testing and Statistics Analysis on Dynamic Response of Expressway Bridge under Various Vehicles

2011 ◽  
Vol 90-93 ◽  
pp. 1033-1038
Author(s):  
Tao Wang ◽  
Wan Shui Han ◽  
Yan Wei Li
Keyword(s):  
Dynamic Response ◽  
Rapid Development ◽  
Bridge Engineering ◽  
Dynamic Responses ◽  
Critical Parameters ◽  
Dynamic Strain ◽  
Coupling Vibration ◽  
Vehicle Type ◽  
Traffic Lane ◽  
Video Recorder

Nowadays, with the rapid development of the traffic infrastructure construction and the growing of the traffic flowing and speed, the vehicle-bridge coupling vibration research has become the focus of the bridge engineering study. The dynamic response of the bridge under the traffic flowing is one of the vital parameters for the vehicle-bridge coupling vibration analysis. In this paper, a methodology, employing the speed radar gun, the video recorder, and the dynamic strain tester in combination with manually recording is used to continuously and detailed investigate the traffic loads on the expressway bridge within 24 hours a day. With this approach introduced by this paper, all the critical parameters, such as the vehicle type, speed, traffic lane, the arriving time of the traffic and the bridge-vehicle dynamic interaction are all recorded. In this investigation, firstly the dynamic responses of 8 pieces of girders of the bridge under 5650 individual vehicles driving through the bridge are recorded, then in conjunction with the investigated traffic flowing samples, in terms of the vehicle type, some detailed statistics study is conducted on the collected records, and finally the space-time distribution laws of the dynamic response of the bridge under the traffic flowing are studied extensively. The result of this study could provide helpful theoretic guidance and supporting data for the vehicle-bridge coupling vibration research.

Dynamic Response in ALF Aggregate Base Asphalt Pavement

2011 ◽  
Vol 97-98 ◽  
pp. 40-44 ◽  
Author(s):  
Chuan Yi Zhuang ◽  
Ai Qin Shen ◽  
Lin Wang
Keyword(s):  
Dynamic Response ◽  
Compressive Stress ◽  
Asphalt Pavement ◽  
Compressive Strain ◽  
Full Scale ◽  
Dynamic Responses ◽  
Traffic Load ◽  
Dynamic Strain ◽  
Strain Response ◽  
Soil Pressure

In order to evaluate pavement dynamic responses accurately under truck loading, the full-scale asphalt pavement accelerated loading facility (ALF) was used. 10 strain gauges and 2 soil pressure cells were installed; temperature sensors were also installed in the different depth of the HMA layer. Pavement response was measured under real traffic load with ALF. The measured pavement responses are compared between the pavement sections to evaluate the effects of various experimental factors, such as axle load, speed, et al. Dynamic strain at the bottom of HMA layer and vertical compressive stress on the top of the subgrade were examined in the full-scale testing road, the regression models between dynamic response and axle load, dynamic response and speed were put forward respectively. Studies show that there is not only tensile strain but also compressive strain in the dynamic response, and the strain response is in the station of tension and compression alternation. Under the intermediate temperature, the strain response at the bottom of the asphalt layer is increased linearly with the increase of axle load and the vertical compressive stresses at the top of the subgrade is also increased with the increase of axle load. Speed has a great effect on strain response at the bottom of HMA layer, and has little effect on vertical compressive stress, it affects the loading duration of stress only. The destroy for the pavement by low speed and heavy load is more serious than that is normal.

scholarly journals The influence of accessory rods and connectors on the dynamic response of spine fixation

2021 ◽  
Author(s):  
Mahmut Pekedis ◽  
Murat Altan ◽  
Turgut Akgul ◽  
Hasan Yildiz
Keyword(s):  
Dynamic Response ◽  
Dynamic Responses ◽  
Dynamic Strain ◽  
Nondestructive Technique ◽  
Lateral Direction ◽  
Group I ◽  
Flexion Extension ◽  
Anterior Corpectomy ◽  
Band Limited ◽  
Spine Fixation

Abstract Purpose This study presents a nondestructive technique to assess the influence of accessory rods and connectors on the dynamic response of spine fixation.Methods Eighteen spine specimens were divided into three construct groups such as group I (2 rods [2R]), II (2 primary rods + 2 accessory rods with 2 transverse connectors [4R+2TC]) and III (2 primary rods + 2 accessory rods with 4 transverse connectors [4R+4TC]). Anterior corpectomy was performed for all specimens. A custom test setup was built to assess the dynamic responses of constructs in flexion-extension (FE) and left-right lateral bending (LRLB) motions. This setup can slide in lateral direction, and it is excited with an electrodynamic shaker vibrated at band limited random frequencies. Accelerometer and reusable dynamic strain sensors were installed on constructs to monitor the dynamic responses. Quasi-static eccentric loading tests were performed to determine the range of motion (RoM).Results The results demonstrated that accessory rods significantly increase the resonance frequency (RF) and decrease the strain over standard 2R construction. Although 4R+4TC provided greatest reduction in rod strain over 4R+2TC and 2R, additional 2 connectors have no significant influence on dynamic response in FE motion.Conclusions An increase in the number of rods has a significant role on the improvement of the fixation's integrity in FE and LRLB motions. However, the additional transverse connectors have significant involvements only in LRLB motion. RF obtained from dynamic tests correlated with the RoM which indicates that the technique could be used as an addendum to the quasi-static test.

Dynamic Analysis of 64-Type Rush-Repair Steel Girder under the Moving Train Loads

2011 ◽  
Vol 199-200 ◽  
pp. 87-91
Author(s):  
Yao Hui Zhang ◽  
Hai Long Wang
Keyword(s):  
Traffic Safety ◽  
Rapid Development ◽  
Dynamic Performance ◽  
Dynamic Responses ◽  
Transportation Engineering ◽  
Steel Girder ◽  
Coupling Vibration ◽  
Engineering Construction ◽  
Technical Requirements ◽  
Highway Transportation

In China, the 64-type rush-repair steel girder developed in 1964 has played a huge role in the railway and highway transportation engineering construction. When it is used as a temporary railway bridge, the original biggest design traffic speed only is 30 km/h. With the rapid development of domestic railway, the dynamic performance of the 64-type rush-repair steel girder must be studied in detail in order to make clear what it can adapt the current technical requirements. In the paper, the structure and technical characteristics of the 64-type rush-repair steel girder are introduced and the dynamic responses of the 64-type rush-repair steel girder are calculated using the train-bridge coupling vibration theory. The main objects of study in paper are the 24m-span and 32m-span girders. The vibration-related laws of the 64-type rush-repair steel girder versus the different train speeds are revealed, and the proposals about the largest reasonable traffic safety speed are given.

scholarly journals Dynamic Response of Parallel Overlapped Tunnel under Seismic Loading by Shaking Table Tests

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Tao Yang ◽  
Yunkang Rao ◽  
Honggang Wu ◽  
Junyun Zhang ◽  
Hao Lei ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Wavelet Packet ◽  
Failure Process ◽  
Side Wall ◽  
Shaking Table ◽  
Dynamic Responses ◽  
Dynamic Strain ◽  
Shaking Table Tests ◽  
Failure Characteristics ◽  
The Right

Potential earthquake-induced damage to overlapped tunnels probably occurs during the operation and maintenance of mountain tunnel engineering, especially in the seismically active zone. This study investigated the dynamic response and the failure characteristics of the parallel overlapped tunnel under seismic loadings by employing shaking table tests. The failure mode of the parallel overlapped tunnels was analyzed through macroscopic test phenomena. The dynamic responses of the surrounding rock and tunnel lining were evaluated by acceleration and dynamic strain, respectively. In particular, wavelet packets were used to investigate the spectrum characteristics of the tunnel structure in depth. The failure process of the model can be divided into three stages. The upper-span and the under-crossing tunnels showed different failure characteristics. Additionally, the lining damage on the outer surface of the tunnel mainly occurred on the right side arch waist and the left side wall, whereas the lining damage on the inner surface of the tunnel mainly appeared on the crown and invert. Wavelet packet energy results showed that the energy characteristic distributions of the upper-span and the under-crossing tunnels were not consistent. Specifically, the energy eigenvalues of the crown of the upper-span tunnel and the invert of the under-crossing tunnel were the largest, which should be considered to be the weak parts in the seismic design.

3-D elastic coupling vibration and acoustical radiation characteristics of cracked gear under elastic support condition

2015 ◽  
Vol 23 (9) ◽  
pp. 1548-1568 ◽  
Author(s):  
Shao Renping ◽  
Purong Jia ◽  
Xiankun Qi
Keyword(s):  
Dynamic Response ◽  
Support System ◽  
Three Dimensional ◽  
Elastic Support ◽  
Dynamic Responses ◽  
Tooth Root ◽  
Support Condition ◽  
Elastic Boundary ◽  
Root Crack ◽  
Elastic Disc

According to the actual working condition of the gear, the supporting gear shaft is treated as an elastic support. Its impact on the gear body vibration is considered and investigated and the dynamic response of elastic teeth and gear body is analyzed. On this basis, the gear body is considered as a three-dimensional elastic disc and the gear teeth are treated as an elastic cantilever beam. Under the conditions of the elastic boundary (support shaft), combining to the elastic disk and elastic teeth, the influence of three-dimensional elastic discs on the meshing tooth response under an elastic boundary condition is also included. A dynamic model of the gear support system and calculated model of the gear tooth response are then established. The inherent characteristics of the gear support system and dynamics response of the meshing tooth are presented and simulated. It was shown by the results that it is correct to use the elastic support condition to analyze the gear support system. Based on the above three-dimensional elastic dynamics analysis, this paper set up a dynamics coupling model of a cracked gear structure support system that considered the influence of a three-dimensional elastic disc on a cracked meshing tooth under elastic conditions. It discusses the dynamic characteristic of the cracked gear structure system and coupling dynamic response of the meshing tooth, offering a three-dimensional elastic body model of the tooth root crack and pitch circle crack with different sizes, conducting the three-dimensional elastic dynamic analysis to the faulty crack. ANSYS was employed to carry out dynamic responses, as well as to simulate the acoustic field radiation orientation of a three-dimensional elastic crack body at the tooth root crack and pitch circle with different sizes.

Evaluation of the Dynamic-Response-Based Intact Stability Criterion for Floating Wind Turbines

2015 ◽  
Author(s):  
Marco Masciola ◽  
Xiaohong Chen ◽  
Qing Yu
Keyword(s):  
Wind Speed ◽  
Dynamic Response ◽  
Wind Turbines ◽  
Stability Criterion ◽  
Area Ratio ◽  
Operating Conditions ◽  
Dynamic Responses ◽  
Stability Criteria ◽  
Intact Stability ◽  
Overturning Moment

As an alternative to the conventional intact stability criterion for floating offshore structures, known as the area-ratio-based criterion, the dynamic-response-based intact stability criteria was initially developed in the 1980s for column-stabilized drilling units and later extended to the design of floating production installations (FPIs). Both the area-ratio-based and dynamic-response-based intact stability criteria have recently been adopted for floating offshore wind turbines (FOWTs). In the traditional area-ratio-based criterion, the stability calculation is quasi-static in nature, with the contribution from external forces other than steady wind loads and FOWT dynamic responses captured through a safety factor. Furthermore, the peak wind overturning moment of FOWTs may not coincide with the extreme storm wind speed normally prescribed in the area-ratio-based criterion, but rather at the much smaller rated wind speed in the power production mode. With these two factors considered, the dynamic-response-based intact stability criterion is desirable for FOWTs to account for their unique dynamic responses and the impact of various operating conditions. This paper demonstrates the implementation of a FOWT intact stability assessment using the dynamic-response-based criterion. Performance-based criteria require observed behavior or quantifiable metrics as input for the method to be applied. This is demonstrated by defining the governing load cases for two conceptual FOWT semisubmersible designs at two sites. This work introduces benchmarks comparing the area-ratio-based and dynamic-response-based criteria, gaps with current methodologies, and frontier areas related to the wind overturning moment definition.

Experimental Investigation on the Dynamic Response of a Three Legged Articulated Type Offshore Wind Tower

2016 ◽  
Author(s):  
Chinsu Mereena Joy ◽  
Anitha Joseph ◽  
Lalu Mangal
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Renewable Energy Sources ◽  
Offshore Structures ◽  
Dynamic Responses ◽  
Offshore Wind ◽  
Experimental Investigations ◽  
Offshore Wind Turbine ◽  
Ocean Engineering ◽  
Study Results

Demand for renewable energy sources is rapidly increasing since they are able to replace depleting fossil fuels and their capacity to act as a carbon neutral energy source. A substantial amount of such clean, renewable and reliable energy potential exists in offshore winds. The major engineering challenge in establishing an offshore wind energy facility is the design of a reliable and financially viable offshore support for the wind turbine tower. An economically feasible support for an offshore wind turbine is a compliant platform since it moves with wave forces and offer less resistance to them. Amongst the several compliant type offshore structures, articulated type is an innovative one. It is flexibly linked to the seafloor and can move along with the waves and restoring is achieved by large buoyancy force. This study focuses on the experimental investigations on the dynamic response of a three-legged articulated structure supporting a 5MW wind turbine. The experimental investigations are done on a 1: 60 scaled model in a 4m wide wave flume at the Department of Ocean Engineering, Indian Institute of Technology, Madras. The tests were conducted for regular waves of various wave periods and wave heights and for various orientations of the platform. The dynamic responses are presented in the form of Response Amplitude Operators (RAO). The study results revealed that the proposed articulated structure is technically feasible in supporting an offshore wind turbine because the natural frequencies are away from ocean wave frequencies and the RAOs obtained are relatively small.

scholarly journals State-of-the-art and annual progress of bridge engineering in 2020

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Renda Zhao ◽  
Kaifeng Zheng ◽  
Xing Wei ◽  
Hongyu Jia ◽  
Haili Liao ◽  
...  
Keyword(s):  
High Performance ◽  
Concrete Bridges ◽  
Bridge Engineering ◽  
Research Progress ◽  
Concrete Bridge ◽  
Steel Bridge ◽  
Bridge Structure ◽  
Coupling Vibration ◽  
Main Research ◽  
Bridge Assessment

AbstractBridge construction is one of the cores of traffic infrastructure construction. To better develop relevant bridge science, this paper introduces the main research progress in China and abroad in 2020 from 16 aspects. The content consists of four major categories in 16 aspects. The first part is about the bridge structure, including concrete bridge and high-performance materials, steel bridges, composite girders. The second part is about the bridge disaster prevention and mitigation, including bridge seismic resistance, wind resistance of bridge, train-bridge coupling vibration research, bridge hydrodynamics, the durability of the concrete bridges, fatigue of steel bridge, temperature field and temperature effect of bridge; The third part is about the bridge analyses, including numerical simulation of bridge structure, box girder and cable-stayed bridge analysis theories. The last part is concerning the bridge emerging technologies, including bridge informatization and intelligent bridge, the technology in bridge structure test, bridge assessment and reinforcement, prefabricated concrete bridge structure.

scholarly journals A New Optimal DTC Switching Strategy for Open-End Windings Induction Machine using Dual Inverter

2021 ◽  
Vol 12 (3) ◽  
pp. 1405
Author(s):  
Nabilah Aisyah ◽  
Maaspaliza Azri ◽  
Auzani Jidin ◽  
M. Z. Aihsan ◽  
MHN Talib
Keyword(s):  
Dynamic Response ◽  
High Speed ◽  
Dynamic Condition ◽  
Dynamic Control ◽  
Direct Torque Control ◽  
Torque Control ◽  
Dynamic Responses ◽  
Voltage Source ◽  
Optimal Switching ◽  
Stator Flux

<span>Since the early 1980s, fast torque dynamic control has been a subject of research in AC drives. To achieve superior torque dynamic control, two major techniques are used, namely Field Oriented Control (FOC) and Direct Torque Control (DTC), spurred on by rapid advances in embedded computing systems. Both approaches employ the space vector modulation (SVM) technique to perform the voltage source inverter into over modulation region for producing the fastest torque dynamic response. However, the motor current tends to increase beyond its limit (which can damage the power switches) during the torque dynamic condition, due to inappropriate flux level (i.e. at rated stator flux). Moreover, the torque dynamic response will be slower, particularly at high speed operations since the increase of stator flux will produce negative torque slopes more often. The proposed research aims to formulate an optimal switching modulator and produce the fastest torque dynamic response. In formulating the optimal switching modulator, the effects of selecting different voltage vectors on torque dynamic responses will be investigated. With greater number of voltage vectors offered in dual inverters, the identification of the most optimal voltage vectors for producing the fastest torque dynamic responses will be carried out based on the investigation. The main benefit of the proposed strategy is that it provides superior fast torque dynamic response which is the main requirements for many AC drive applications, e.g. traction drives, electric transportations and vehicles.</span>

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