Wind loads on a moving vehicle-bridge deck system by wind-tunnel model test

Li, Yongle,Hu, Peng,Xu, You-Lin,Zhang, Mingjin,Liao, Haili Techno-Press 2014 Wind and Structures, An International Journal (WAS Vol.19 No.2

Wind-vehicle-bridge (WVB) interaction can be regarded as a coupled vibration system. Aerodynamic forces and moment on vehicles and bridge decks play an important role in the vibration analysis of the coupled WVB system. High-speed vehicle motion has certain effects on the aerodynamic characteristics of a vehicle-bridge system under crosswinds, but it is not taken into account in most previous studies. In this study, a new testing system with a moving vehicle model was developed to directly measure the aerodynamic forces and moment on the vehicle and bridge deck when the vehicle model moved on the bridge deck under crosswinds in a large wind tunnel. The testing system, with a total length of 18.0 m, consisted of three main parts: vehicle-bridge model system, motion system and signal measuring system. The wind speed, vehicle speed, test objects and relative position of the vehicle to the bridge deck could be easily altered for different test cases. The aerodynamic forces and moment on the moving vehicle and bridge deck were measured utilizing the new testing system. The effects of the vehicle speed, wind yaw angle, rail track position and vehicle type on the aerodynamic characteristics of the vehicle and bridge deck were investigated. In addition, a data processing method was proposed according to the characteristics of the dynamic testing signals to determine the variations of aerodynamic forces and moment on the moving vehicle and bridge deck. Three-car and single-car models were employed as the moving rail vehicle model and road vehicle model, respectively. The results indicate that the drag and lift coefficients of the vehicle tend to increase with the increase of the vehicle speed and the decrease of the resultant wind yaw angle and that the vehicle speed has more significant effect on the aerodynamic coefficients of the single-car model than on those of the three-car model. This study also reveals that the aerodynamic coefficients of the vehicle and bridge deck are strongly influenced by the rail track positions, while the aerodynamic coefficients of the bridge deck are insensitive to the vehicle speed or resultant wind yaw angle.

Wind loads on a moving vehicle–bridge deck system by wind-tunnel model test

Yongle Li,Peng Hu,You-Lin Xu,Mingjin Zhang,Haili Liao 한국풍공학회 2014 Wind and Structures, An International Journal (WAS Vol.19 No.2

Wind-vehicle-bridge (WVB) interaction can be regarded as a coupled vibration system. Aerodynamic forces and moment on vehicles and bridge decks play an important role in the vibration analysis of the coupled WVB system. High-speed vehicle motion has certain effects on the aerodynamic characteristics of a vehicle-bridge system under crosswinds, but it is not taken into account in most previous studies. In this study, a new testing system with a moving vehicle model was developed to directly measure the aerodynamic forces and moment on the vehicle and bridge deck when the vehicle model moved on the bridge deck under crosswinds in a large wind tunnel. The testing system, with a total length of 18.0 m, consisted of three main parts: vehicle-bridge model system, motion system and signal measuring system. The wind speed, vehicle speed, test objects and relative position of the vehicle to the bridge deck could be easily altered for different test cases. The aerodynamic forces and moment on the moving vehicle and bridge deck were measured utilizing the new testing system. The effects of the vehicle speed, wind yaw angle, rail track position and vehicle type on the aerodynamic characteristics of the vehicle and bridge deck were investigated. In addition, a data processing method was proposed according to the characteristics of the dynamic testing signals to determine the variations of aerodynamic forces and moment on the moving vehicle and bridge deck. Three-car and single-car models were employed as the moving rail vehicle model and road vehicle model, respectively. The results indicate that the drag and lift coefficients of the vehicle tend to increase with the increase of the vehicle speed and the decrease of the resultant wind yaw angle and that the vehicle speed has more significant effect on the aerodynamic coefficients of the single-car model than on those of the three-car model. This study also reveals that the aerodynamic coefficients of the vehicle and bridge deck are strongly influenced by the rail track positions, while the aerodynamic coefficients of the bridge deck are insensitive to the vehicle speed or resultant wind yaw angle.

Dynamic analysis of wind-vehicle-bridge systems using mutually-affected aerodynamic parameters

Wang, Bin,Xu, You-Lin,Li, Yongle Techno-Press 2015 Wind and Structures, An International Journal (WAS Vol.20 No.2

Several frameworks for the dynamic analysis of wind-vehicle-bridge systems were presented in the past decade to study the safety or ride comfort of road vehicles as they pass through bridges under crosswinds. The wind loads on the vehicles were generally formed based on the aerodynamic parameters of the stationary vehicles on the ground, and the wind loads for the pure bridge decks without the effects of road vehicles. And very few studies were carried out to explore the dynamic effects of the aerodynamic interference between road vehicles and bridge decks, particularly for the moving road vehicles. In this study, the aerodynamic parameters for both the moving road vehicle and the deck considering the mutually-affected aerodynamic effects are formulized firstly. And the corresponding wind loads on the road vehicle-bridge system are obtained. Then a refined analytical framework of the WVB system incorporating the resultant wind loads, a driver model, and the road roughness in plane to fully consider the lateral motion of the road vehicle under crosswinds is proposed. It is shown that obvious lateral and yaw motions of the road vehicle occur. For the selected single road vehicle passing a long span bridge, slight effects are caused by the aerodynamic interference between the moving vehicle and deck on the dynamic responses of the system.

Dynamic analysis of wind-vehicle-bridge systems using mutually-affected aerodynamic parameters

Bin Wang,You-Lin Xu,Yongle Li 한국풍공학회 2015 Wind and Structures, An International Journal (WAS Vol.20 No.2

Several frameworks for the dynamic analysis of wind-vehicle-bridge systems were presented inthe past decade to study the safety or ride comfort of road vehicles as they pass through bridges undercrosswinds. The wind loads on the vehicles were generally formed based on the aerodynamic parameters ofthe stationary vehicles on the ground, and the wind loads for the pure bridge decks without the effects ofroad vehicles. And very few studies were carried out to explore the dynamic effects of the aerodynamicinterference between road vehicles and bridge decks, particularly for the moving road vehicles. In this study,the aerodynamic parameters for both the moving road vehicle and the deck considering themutually-affected aerodynamic effects are formulized firstly. And the corresponding wind loads on the roadvehicle-bridge system are obtained. Then a refined analytical framework of the WVB system incorporatingthe resultant wind loads, a driver model, and the road roughness in plane to fully consider the lateral motionof the road vehicle under crosswinds is proposed. It is shown that obvious lateral and yaw motions of theroad vehicle occur. For the selected single road vehicle passing a long span bridge, slight effects are causedby the aerodynamic interference between the moving vehicle and deck on the dynamic responses of thesystem.

GPS 차량주행궤적자료와 MOVES 데이터베이스를 활용한 미시배출계수 추정 연구

허혜정,신현주,김재헌,이건우 한국도로학회 2022 한국도로학회논문집 Vol.24 No.4

PURPOSES : A methodology for estimating micro-emission factors using vehicle trajectory data collected from navigation and DTG devices and basic emission factors for each vehicle type of the MOtor Vehicle Emission Simulator (MOVES) is presented. The methodology can calculate micro-emissions based on only the traffic volume and average speed for each vehicle type. METHODS : Cluster analysis was performed by accumulating the trajectories of individual vehicles on a specific road section into speed groups in which vehicles drove with the same range of average speed. Then, the micro-emission factors were estimated for each speed group. RESULTS : Using the vehicle trajectory data revealed that the emissions calculated from micro-emission factors estimated by the proposed methodology were similar to the sum of the emissions calculated from the vehicle trajectories for each vehicle. CONCLUSIONS : The micro-emission factor database for each road type and vehicle type proposed in this study should be useful for estimating vehicle emissions on the road. The proposed method can calculate emissions in the same way as the macroscopic analysis method, using the traffic volume, average speed, and link length

차세대 자율주행차 시트 디자인 개발

홍성경(Sungkyung Hong),신성훈(Sunghoon Shin),장지혜(Jihye Jang) 한국자동차공학회 2018 한국자동차공학회 학술대회 및 전시회 Vol.2018 No.11

Autonomous driving is a vehicle that can scan a road condition and drive itself without human conduction. Recently, Autonomous vehicle research and development studies are accelerating and companies are competing about direction of autonomous vehicle. Vehicle technologies are developed by vehicle manufacturer for decades. Unlike vehicle technologies, autonomous vehicle technologies are developed by IT companies in advance. For these reasons, we can refer that “smart” technologies, which can be called artificial intelligence, are another ways to approach core technology of vehicle. Autonomous vehicle commercialization requires lots of changes such as traffic rules, new environments, and sensor technologies. Most of all, connection with vehicles and humans are huge changes that requires. In addition, drivers will be free in vehicle interior space without conduction. In this article, we will set a keyword as “Moving Space Concept” for autonomous vehicle and study seats roles in the moving space. First of all, analyze future trend and discover customers’ needs base on the analysis. Second, propose autonomous vehicle seat layout for new concept. Unlike purchasing personal vehicle, customers might want ridesharing. However, in the article, studies will set limits to autonomous vehicle as a privately-owned car.

Elimination of moving vehicles effects on modal identification of beam type bridges

Wen-Yu He,Xu-Cong Ding,Wei-Xin Ren,Yue-Ling Jing 국제구조공학회 2021 Smart Structures and Systems, An International Jou Vol.28 No.3

The modal parameters identified under operation conditions are normally employed for bridge damage detection. However, the moving vehicles are usually deemed as part of the operation conditions without considering their mass property. Thus, the identified modal parameters belong to the vehicle-bridge system rather than the bridge itself, which would affect the effectiveness of subsequent damage detection. In this paper, the effects of moving vehicles on the identified frequencies and mode shapes under operation conditions are investigated via finite element model. The necessary of considering the moving vehicle effects is demonstrated by comparing the modal parameters variations induced by the moving vehicle and bridge damage. Then the empirical formulas to eliminate the moving vehicle effects considering the vehicle mass, velocity, bridge span and relative position are established by using the orthogonal test and least square method. Finally, examples are conducted to verify of the effectiveness of the proposed empirical formulas.

한국형 운행 모드 기반 배출량 산정 모형 개발에 관한 연구

허혜정,Christopher Frey,윤천주,양충헌,김진국 대한교통학회 2016 大韓交通學會誌 Vol.34 No.2

Atmospheric pollutants such as Nitrogen Oxides(NOx), Carbon Monoxide(CO), Carbon Dioxide(CO2), Particulate Matter(PM) and Hydrocarbons(HC) come from vehicle exhaust gases. Emission curves based on average travel speeds have been employed for estimating on-road emissions as well as evaluating environmental impacts of transportation plans and policies in Korea. Recently, there is a growing interest in estimation methods of vehicle emissions considering relationship between vehicle dynamic driving characteristics and emissions, and incorporating such emission estimators into traffic simulation models. MOVES Lite, a simplified version of MOVES, is one of the estimation methods. In this study, the authors performed a study to develop an adaptable version of MOVES Lite for Korea, called MOVES Lite-K. Vehicle types, driving characteristics, emission rates, and emission standards of Korea were reflected in MOVES Lite-K. The characteristics of emission calculation of MOVES Lite-K and NIER emission curves were compared and the adaptability of MOVES Lite-K were examined. 차량의 배기가스에는 질소산화물(NOx), 일산화탄소(CO), 이산화탄소(CO2), 입자상 물질(PM), 탄화수소(HC)와 같은 대기 오염물질이 포함되어 있다. 이러한 도로이동오염원의 배출량을 산정하기 위하여 한국에서는 평균속도 기반의 배출계수 곡선식을 사용하고 있으며 교통 계획과 교통 정책의 대안 평가에서 환경적 영향을 분석할 때 활용하고 있다. 그러나 최근에는 차량의 동적 운행 특성과 배출량의 관계를 보다 정확하게 반영하여 배출량을 산정할 수 있는 방법론과 이 방법론을 교통 시뮬레이션 모형에 통합하는 것에 대한 관심이 증가하고 있다. MOVES Lite는 MOVES의 간략 버전으로서 교통 시뮬레이션 모형에 통합될 수 있도록 개발된 운행모드 기반 배출량 산정모형이다. 본 연구에서는 한국의 차종, 주행특성, 배출계수, 배출규제 등을 반영하여 MOVES Lite를 개량한 MOVES Lite-K를 개발하기 위한 연구를 수행하였고, 국내의 대표적 배출량 산정 방법인 평균속도 기반의 배출계수 곡선식과 MOVES Lite-K의 배출량 산정 특성을 비교하여 두 방법론의 차이와 국내 적용성을 살펴보았다.

Crosswind effects on high-sided road vehicles with and without movement

Wang, Bin,Xu, You-Lin,Zhu, Le-Dong,Li, Yong-Le Techno-Press 2014 Wind and Structures, An International Journal (WAS Vol.18 No.2

The safety of road vehicles on the ground in crosswind has been investigated for many years. One of the most important fundamentals in the safety analysis is aerodynamic characteristics of a vehicle in crosswind. The most common way to study the aerodynamic characteristics of a vehicle in crosswind is wind tunnel tests to measure the aerodynamic coefficients and/or pressure coefficients of the vehicle. Due to the complexity of wind tunnel test equipment and procedure, the features of flow field around the vehicle are seldom explored in a wind tunnel, particularly for the vehicle moving on the ground. As a complementary to wind tunnel tests, the numerical method using computational fluid dynamics (CFD) can be employed as an effective tool to explore the aerodynamic characteristics of as well as flow features around the vehicle. This study explores crosswind effects on a high-sided lorry on the ground with and without movement through CFD simulations together with wind tunnel tests. Firstly, the aerodynamic forces on a stationary lorry model are measured in a wind tunnel, and the results are compared with the previous measurement results. The CFD with unsteady RANS method is then employed to simulate wind flow around and wind pressures on the stationary lorry. The numerical aerodynamic forces are compared with the wind tunnel test results. Furthermore, the same CFD method is extended to investigate the moving vehicle on the ground in crosswind. The results show that the CFD results match with wind tunnel test results and the current way using aerodynamic coefficients from a stationary vehicle in crosswind is acceptable. The CFD simulation can provide more insights on flow field and pressure distribution which are difficult to be obtained by wind tunnel tests.

Crosswind effects on high-sided road vehicles with and without movement

Bin Wang,You-Lin Xu,Le-Dong Zhu,Yong-Le Li 한국풍공학회 2014 한국풍공학회지 Vol.18 No.2

The safety of road vehicles on the ground in crosswind has been investigated for many years. One of the most important fundamentals in the safety analysis is aerodynamic characteristics of a vehicle in crosswind. The most common way to study the aerodynamic characteristics of a vehicle in crosswind is wind tunnel tests to measure the aerodynamic coefficients and/or pressure coefficients of the vehicle. Due to the complexity of wind tunnel test equipment and procedure, the features of flow field around the vehicle are seldom explored in a wind tunnel, particularly for the vehicle moving on the ground. As a complementary to wind tunnel tests, the numerical method using computational fluid dynamics (CFD) can be employed as an effective tool to explore the aerodynamic characteristics of as well as flow features around the vehicle. This study explores crosswind effects on a high-sided lorry on the ground with and without movement through CFD simulations together with wind tunnel tests. Firstly, the aerodynamic forces on a stationary lorry model are measured in a wind tunnel, and the results are compared with the previous measurement results. The CFD with unsteady RANS method is then employed to simulate wind flow around and wind pressures on the stationary lorry. The numerical aerodynamic forces are compared with the wind tunnel test results. Furthermore, the same CFD method is extended to investigate the moving vehicle on the ground in crosswind. The results show that the CFD results match with wind tunnel test results and the current way using aerodynamic coefficients from a stationary vehicle in crosswind is acceptable. The CFD simulation can provide more insights on flow field and pressure distribution which are difficult to be obtained by wind tunnel tests.