유연체 판스프링 모델을 이용한 서스펜션 지오메트리 연구

김기태(Gitae Kim),문일동(Ildong Moon),임정환(Junghwan Lim) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

This paper proposes a modeling technique which is able to not only reliably and easily represent the wheel rate but also analyze the suspension characteristics. The flexible body model of the leaf spring is developed by interfacing the finite element model and computation model of the leaf spring. The SPMD test of the vehicle is conducted for the validation of the reliability of the flexible body model of the leaf spring developed in this paper. The SPMD test is started at an constraint state of frame using the jig with the excitation amplitude of 1-2㎜/sec. The simulation is conducted with the same condition as the SPMD test. Then, the simulations are conducted with bump mode and roll mode. The diagram of wheel rate and wheel alignment from the SPMD test is compared with the ones from the simulation for the validation of the reliability of the model. The flexible body of the leaf spring is compared with the rigid body of the leaf spring. The sensitivity analysis of the front suspension and steering system is also conducted with the developed flexible body model under a bump mode of K&C analysis.

풍력을 이용한 선박의 돛 캠버에 대한 공기력 해석에 대한 연구

문병영,장세명 한국유체기계학회 2015 한국유체기계학회 논문집 Vol.18 No.2

In the design of sailing yachts, para-glider, or high-sky wind power, etc., the analysis of side-wind aerodynamic forcesexerted on a cambered 3-D model is very important to predict the performance of various machinery systems. To understandthe essential flow physics around the three-dimensional shape, simplified rigid-body models are proposed in this study. Fourparameters such as free stream velocity, angle of attack, aspect ratio, and camber are considered as the independent variables. Lift and drag coefficients are computed with CFD technique using ANSYS-CFX, and the results with the visualization ofpost-processed flow fields are analyzed in the viewpoint of fluid dynamics.

불연속체 구조물의 해석을 위한 강체-고체 복합모델의 개발

김승덕,정하선 한국전산구조공학회 1998 한국전산구조공학회논문집 Vol.11 No.4

불연속적 거동이 탁월한 벽식 프리캐스트 구조물을 해석하기 위한 방법으로 유한요소법과 강체요소법 등이 있으나, 이들 해석법은 접합부의 거동을 정확히 반영하지 못하고 있다. 본 연구에서는 패널은 강체적 거동을 하고, 판널과 판널 사이의 접합부는 고체적 거동을 가정하는 강체-고체 복합모델(Coupled Model by Rigid and Solid bodies)에 의한 해석법을 제안하며, 간단한 모델의 예를 통해 검증하였다.

캠버가 있는 3차원 박판 강체 모형의 측풍 공기력에 대한 수치 연구

신종현(Jong-Hyeon Shin),장세명(Se-Myong Chang),문병영(Byung-Young Moon) 한국항공우주학회 2015 韓國航空宇宙學會誌 Vol.43 No.2

돛 요트, 패러글라이더, 또는 고공 풍력 등의 설계에 있어, 3차원 모델에 가해지는 측풍 공기력을 해석하는 일은 다양한 기계의 성능을 예측하기 위해 매우 중요하다. 3차원 형상 주위의 본질적인 유동 물리를 이해하기 위하여, 본 연구에서는 간략화된 강체 모델들이 제안되었다. 자유류 속도, 받음각, 종횡비, 그리고 캠버가 독립변수로서 고려되었다. 양력과 항력 계수들은 ANSYS-CFX를 이용한 전산유체역학 해석을 통하여 계산되었고, 유동장의 후처리된 가시화 결과는 유체역학의 관점에서 해석되었다. In the design of sailing yachts, para-glider, or high-sky wind power, etc., the analysis of side-wind aerodynamic forces exerted on a cambered 3-D model is very important to predict the performance of various machinery systems. To understand the essential flow physics around the three-dimensional shape, simplified rigid-body models are proposed in this study. Four parameters such as free stream velocity, angle of attack, aspect ratio, and camber are considered as the independent variables. Life and drag coefficients are computed with CFD technique using ANSYS-CFX, and the results with the visualization of post-processed flow fields are analyzed in the viewpoint of fluid dynamics.

Sail 요트의 공기력에 대한 강체 모형의 광역 파라미터에 관한 기초 연구

선민영,문병영,Sun, M.Y.,Moon, B.Y. 한국마린엔지니어링학회 2014 한국마린엔지니어링학회지 Vol.38 No.4

In the design of sailing yachts, the analysis of aerodynamic forces exerted on sails is very important to predict the performance of propulsion of a ship. To understand the essential flow physics around the sail, a simplified rigid-body sail model is proposed in this study. Four parameters such as free stream velocity, angle of attack, maximum width of sail, and camber length are considered as the independent variables. Lift and drag coefficients are computed with CFD technique using ANSYS-CFX, and the results with the visualization of flow field are analyzed in the viewpoint of fluid dynamics. 본 연구에서는 범선형 요트에 작용하는 공기력을 해석하기 위하여 매우 단순화된 표준 강체 모형을 제시하였다. 모델의 전산유체역학 해석을 통하여 자유류 속도, 받음각, 돛의 최대 폭, 캠버 길이에 대한 광범위 파라미터 연구를 실시하였다. 삼각 돛과 사각 돛에 대한 양력계수와 항력계수가 분석되었으며, 각각의 인자에 대한 물리적 해석을 실시하였다. 자유류 속도에 대해서 주어진 인자 범위의 Reynolds 수영역 내에서 삼각 돛은 캠버와 공력 계수가 순방향의 민감도를 보이는 반면, 사각 돛은 역방향의 민감도를 보이는 사실을 확인하였다. 또한 와도의 분석 결과 돛 뒷면의 앞전에서 발생하는 유동 박리에 의한 와류 강도의 복잡한 3차원적 간섭에 의해 후류의 와도가 영향을 받는 것으로 밝혀졌다. 이러한 연구를 통하여 돛의 주변에 나타나는 유동 물리 현상을 좀 더 깊이 이해하고 추후 범선형 요트 설계를 위한 주요 외력 인자와 민감도를 기저 값으로 이용하여 요트를 설계하고자 한다.

골격근 활성도를 고려한 남성 50% articulated rigid body 모델을 이용한 썰매 실험 해석

김영만(Youngman Kim),사성진(Sungjin Sah),조현석(Hyunseok Jo),강성재(Seongjae Kang),최형연(Hyung-Yun Choi),이진희(Jinhee Lee),문무성(Museong Moon) 한국자동차공학회 2004 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

It is a main purpose that sled test measures the acceleration pulse of sled, volunteer and dummy attached an accelerometer and analyzes how their motions are. However in this study, sled test analyzes mainly stiffened muscles due to the crash stress before the crash happens. Test equipment was embodied the same environment of driving seat of a middle size car so that we can realized the real driving posture and we induced enough crash-risk of volunteers during the direct￢crash. Also. we applied H-ARB(Human Articulated Rigid body) included hill type muscles on the analysis of sled test. And then we validated a load cell pulse of steering wheel and brake pedal, pressure sensor of back seat and EMG signal of each muscle by using the optimization.

Design and Analysis on The Connections of RC Precast Large Panel

Park, Kang-Geun 한국공간구조학회 2006 한국공간구조학회지 Vol.6 No.2

본 연구에서는 철근콘크리트 프리캐스트 대형판의 접합부 설계방법 및 해석방법에 대해서 연구를 수행하였다. 접합부의 설계방법은 수평접합부와 수직접합부의 구조적 거동에 대한 안정성 및 일체성을 확보하기 위한 설계법을 제시하였고, 접합부의 해석은 강체스프링 모델에 의한 탄소성해석을 수행 하였다. Precast large panel structures have various connection system such as the horizontal slab-to-wall connection, the vertical wall to wall connection, horizontal slab-to-slab connection, etc. Horizontal connection is connected by vertical tie bars, and vertical joint is connected loop bars and shear keys. The basic function is equalized deformations on later forces and the entire wall panel assembly acts as monolithic actions. Under lateral load some slip occurs in almost vertical connections. The shape and detail of precast connections are very important to the monolithic behavior of overall structures. The paper is a study on the design method and new elasto-plastic analysis of the connections by rigid-bodies spring model.

반응표면법에 의한 연약지반 차량 거동의 통계적 분석 및 예측

이태희(TAE-HEE LEE),정재준(JAE-JUN JUNG),홍섭(SUP HONG),김형우(HYUNG-WOO KIM),최종수(JONG-SU CHOI) 한국해양공학회 2006 韓國海洋工學會誌 Vol.20 No.3

For optimal design of a deep-sea ocean mining collector system,based on self-propelled mining vehicle, it is imperative to develop and validate the dynamic model of a tracked vehicle traveling on soft deep seabed. The purpose of this paper is to evaluate the fidelity of the dynamic simulation model by means of response surface methodology. Various statistical techniques related to response surface methodology, such as outlier analysis, detection of interaction effect, analysis of variance, inference of the significance of design variables, and global sensitivity analysis, are examined. To obtain a plausible response surface model, maximum entropy sampling is adopted. From statistical analysis and prediction for dynamic responses of the tracked vehicle, conclusions will be drawn about the accuracy of the dynamic model and the performance of the response surface model.

헬리콥터 동체의 진동 예측

윤철용(Chul Yong Yun),김도형(Do-Hyung Kim),강희정(Hee Jung Kang) 한국소음진동공학회 2013 한국소음진동공학회 학술대회논문집 Vol.2013 No.4

This paper describes a helicopter vibration induced by main rotor in forward flight. The hub loads in the fixed frame, which are dominant source of helicopter vibration, are obtained by multi-blade summation of rotating blades loadings. The components of 3/rev, 4/rev, and 5/rev blades loadings are transmitted by blades to 4/rev hub loads in the fixed frame. The vertical vibrations of helicopter at pilot seat and copilot seat are calculated through rigid body transfer functions considering airframe to be rigid body. The blades are assumed to be elastic and undergo the flap, lag, and torsion motion and free wake aerodynamic model is used to calculate the precise blade loadings in the analysis. The 4/rev vertical vibration responses are analyzed from rotating blade loadings and fixed hub loadings.

모듈시험을 통한 밸런스 샤프트 동특성 평가

배철용(Chulyong Bae),김찬중(Chanjung Kim),이봉현(Bonghyun Lee),권성진(Seongjin Kwon),나병철(Byungchul Na),김현철(Hyunchul Kim) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

Generally, a balance shaft for 4 cylinder diesel engine is an important component for the compensation of the inertia force due to dynamic unbalance at driving status. But in domestic vehicle industry, its development technique is limited to only manufacturing skills instead of design techniques. Therefore, on this study in order to present the basic design technique the dynamic characteristics of balance shaft are analysed using module experiments which are the vibration test and the driving torque test. Also the analytical model for multi-body dynamics analysis is composed. The composed analytical model is verified by comparison with the result of module experiments.