• Title/Summary/Keyword: Vehicle Structures

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Guideline for the Design of Wall-Climbing Mobile Robot Using Permanent Magnetic Wheels (영구 자석 바퀴를 이용한 벽면 이동 로봇의 설계시의 설계지침)

  • 이화조;김은찬;한승철
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.10a
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    • pp.548-553
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    • 2002
  • Most tasks of the large vertical or ceiling structures have been carried out by human power. Those tasks require us much operation costs and times, safety devices, etc. So the need of automation for those tasks have been rising. That automation needs a wall-climbing mobile vehicle. Most former researches are things about attachment devices and moving mechanisms. A wall-climbing mobile vehicle must be designed by a method different from the case of the vehicle of the horizontal environment. That is because gravity acts as a negative role on the stability of a wall-climbing vehicle. In this thesis, the particular shape characteristics of a wall-climbing mobile vehicle are derived by the wall-environment modeling. In addition, some design constraints of the permanent magnetic wheel as an attachment device was studied. According to those requirements and constraints, one specific wall-climbing mobile vehicle was designed and some experiments were made on the attachment ability of that vehicle.

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Variability in bridge frequency induced by a parked vehicle

  • Chang, K.C.;Kim, C.W.;Borjigin, Sudanna
    • Smart Structures and Systems
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    • v.13 no.5
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    • pp.755-773
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    • 2014
  • The natural frequency of a bridge is an important parameter in many engineering applications such as bridge seismic design and modal-based bridge health monitoring. The natural frequency of a bridge vibrating alone may differ from that vibrating along with a vehicle. Although such vehicle-induced variability in bridge frequency is revealed in several experimental and numerical simulation studies, few attempts have been made on the theoretical descriptions. In this study, both theoretically and experimentally, the variability in the bridge frequency induced by a parked vehicle is verified, and is therefore suggested to be considered in bridge-related engineering, especially for those cases with near vehicle-bridge resonance conditions or with large vehicle-to-bridge mass ratios. Moreover, the variability ranges could be estimated by an analytical formula presented herein.

Development of Automated Structural Design and Analysis Aided-Program of Aluminum Extrusion Carbody Structures for Railway Vehicle (알루미늄 압출재 철도차량 차체 구조물의 자동화 구조 설계 및 해석 지원 프로그램 개발)

  • Kim, Jun-Hwan;Shin, Kwang-Bok;Kang, Seung-Gu;Lee, Young-Ju
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.2679-2683
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    • 2011
  • The purpose of this study is to develop automated structural design and analysis aided-program of aluminum extrusion carbody structures for railway vehicle. This developed program is possible to perform simultaneously structural design and design verification of aluminum extrusion profiles independent of expertise and experience of design engineers. Design engineers was able to design it using database of existing aluminum extrusion profiles or user-defined function. The design verification was programmed to evaluate its structural integrity according to Korean Railway Safety Law or Urban Transit Safety Law. Also, this program could automatically generate an executable file of various commercial finite element program and CAD files such as stp and iges by GUI environment applications using MFC(Microsoft Foundation Classes). In conclusion, it is expected to contribute to reduce product development time and improve product quality of aluminum extrusion profile and structures in railway industry.

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Frontal Crashworthiness Analysis of Vehicle Using simplified Structure Modelling (단순 차체 모델링을 이용한 차량 정면충돌해석)

  • 김홍수;강신유;이인혁;박신희;한동철
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.2
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    • pp.23-30
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    • 1997
  • Modelling and crashworthiness analysis of simplified vehicle structures with beam element and nonlinear spring element to which axial and bending collapse mecha- nisms are applied are carried out. And on the basis of these analyses, two types of full car modelling and crahworthiness analyses with nonlinear spring and beam element are accomplished. The one is the full car model of which 30% of the structures are modelled with nonlinear spring and beam element, and the other 75% of whole structures. And the results are compared with those of full car analysis with shell element.

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Development of Vibration and Noise Prediction Softwares for Vehicle Structures Using Power Flow Analysis (파워흐름해석법을 이용한 자동차 구조물의 진동/소음 예측 프로그램 개발)

  • Lee, Ho-Won;Hong, Suk-Yoon;Seo, Sung-Hoon;Kwon, Hyun-Wung;Park, Young-Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.391-397
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    • 2005
  • Power Flow Analysis(PFA) is used as the promising tools for the vibration and noise predictions of complex structures in medium-to-high frequency ranges. When the noise and vibration of a complex structure are analyzed, Power Flow finite Element Method combining PFA with FEM is efficient in vibration analysis, and Power Flow Boundary element Method combining PFA with BEM is usful in noise analysis. PFFEM software, PFADS has been developed for the vibration analysis of coupled system structures. Also, NASPFA, the noise analysis software based on PFBEM, has been developed. Through the several upgrades, the current version PFADS R3 and NASPFA R2 are used for the vibration and noise analysis of system structures in medium-to-high frequency ranges. In this paper, the structure and function of each software are explained, and the vibration and noise levels of vehicle structures predicted by each software are shown.

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A Study on the Vibration Characteristics of 3-Dimension Submerged Vehicle in Consideration of Fluid-Structure Interaction (유체력을 고려한 3차원 수중압력선체의 진동특성에 관한 연구)

  • 손충렬;김경수;변효인
    • Journal of Ocean Engineering and Technology
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    • v.15 no.1
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    • pp.19-25
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    • 2001
  • Unlike structures in the air, the vibration analysis of a submerged or floating structure such as offshore structures or ships is possible only when the fluid-structure interaction is understood, as the whole or part of the structure is in contact with water. This paper introduces two methods to find natural frequency in consideration of fluid-structure interaction, direct coupled vibration analysis and fluid-structure modal coupled vibration analysis. The purpose of this study is to analyze the vibration characteristic of a submerged vehicle to obtain the anti-vibration design data, which could be used in the preliminary design stage. The underwater pressure hull of submerged vehicle is used as the model of this study. The F.E.M. model is meshed by shell and beam elements. Also, considering the inner hull weight, the mass element is distributed in the direction of hull length. Numerical calculations are accomplished by using the commercial B.E.M. code. The characteristics of natural frequency, mode shape and frequency-displacement response are analyzed.

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Damage identification of vehicle-track coupling system from dynamic responses of moving vehicles

  • Zhu, Hong-Ping;Ye, Ling;Weng, Shun;Tian, Wei
    • Smart Structures and Systems
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    • v.21 no.5
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    • pp.677-686
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    • 2018
  • The structural responses are often used to identify the structural local damages. However, it is usually difficult to gain the responses of the track, as the sensors cannot be installed on the track directly. The vehicles running on a track excite track vibration and can also serve as response receivers because the vehicle dynamic response contains the vibration information of the track. A damage identification method using the vehicle responses and sensitivity analysis is proposed for the vehicle-track coupling system in this paper. Different from most damage identification methods of vehicle-track coupling system, which require the structural responses, only the vehicle responses are required in the proposed method. The local damages are identified by a sensitivity-based model updating process. In the vehicle-track coupling system, the track is modeled as a discrete point supported Euler-Bernoulli beam, and two vehicle models are proposed to investigate the accuracy and efficiency of damage identification. The measured track irregularity is considered in the calculation of vehicle dynamic responses. The measurement noises are also considered to study their effects to the damage identification results. The identified results demonstrate that the proposed method is capable to identify the local damages of the track accurately in different noise levels with only the vehicle responses.

Dynamic response of railway vehicles under unsteady aerodynamic forces caused by local landforms

  • Chen, Zhengwei;Liu, Tanghong;Li, Ming;Yu, Miao;Lu, Zhaijun;Liu, Dongrun
    • Wind and Structures
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    • v.29 no.3
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    • pp.149-161
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    • 2019
  • When a railway vehicle runs in crosswinds, the unsteady aerodynamic forces acting on the train induced by the vehicle speed, crosswind velocity and local landforms are a common problem. To investigate the dynamic performance of a railway vehicle due to the influence of unsteady aerodynamic forces caused by local landforms, a vehicle aerodynamic model and vehicle dynamic model were established. Then, a wind-loaded vehicle system model was presented and validated. Based on the wind-loaded vehicle system model, the dynamic response performance of the vehicle, including safety indexes and vibration characteristics, was examined in detail. Finally, the effects of the crosswind velocity and vehicle speed on the dynamic response performance of the vehicle system were analyzed and compared.

Dynamic Performance Evaluation of Concrete Barrier Systems for Small Vehicle Roadway (소형차 전용도로를 위한 콘크리트 차량방호울타리의 동적성능 평가)

  • Hwang, In-Tae;Lee, Dong-Woo;Choi, Hyun-Ho;Woo, Kwang-Sung
    • International Journal of Highway Engineering
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    • v.14 no.4
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    • pp.113-124
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    • 2012
  • PURPOSES : In This study two different concrete barrier systems have been proposed to be established at the small vehicle driveway. One is for median barrier, and the other is for roadside barrier. METHODS : In order to determine the suitable shape of barrier, the impact parameters including vehicle weight, impact angle, impact velocity and impact level have been analyzed. The real crash test has been carried out with 0.9 ton and 2.5 ton vehicles, respectively by using the 2m segment type concrete barriers connected by steel plates that are totally 40m barrier systems. RESULTS : The numerical results obtained by LS/DYNA-3D software are compared with real crash tests from the viewpoints of vehicle stability, vehicle trajectory, occupant risk, etc. CONCLUSIONS : From the above results, the dynamic performance of proposed barrier systems satisfies the specification of Korean Code for roadside safety structures.

Structural Design Optimization of the Aluminum Space Frame Vehicle (알루미늄 스페이스 프레임 차량의 구조 최적화 설계 기법)

  • Kang, Hyuk;Kyoung, Woo-Min
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.1
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    • pp.175-180
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    • 2008
  • Due to the global environment problems and the consumer's need for higher vehicle performance, it becomes very important for the global car makers to reduce vehicle weight. To reduce vehicle weight, many car makers have tried to use lightweight materials, for example, aluminum, magnesium, and plastics, for the vehicle structures and components. Especially, the ASF(aluminum space frame) is known for the excellent concept of the vehicle to satisfy structural rigidity, safety performance and weight reduction. In this research, the design of experiments and the multi-disciplinary optimization technique were utilized to meet the weight and structural rigidity target of the ASF. For the structural performance of the ASF, the locations and the size of aluminum extruded frames, aluminum cast nodes, and the aluminum sheets were optimized. As a result, the optimization design procedure has been set up to meet both structural and weight target of the ASF, and the assembled ASF showed good structural performance and weight reduction.