• 대한기계학회논문집A
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• 제29권2호
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• pp.270-276
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• 2005

This paper develops the flexible computational model of a heavy truck by interfacing the frame modeled as a flexible body to the heavy truck's computational model composed of rigid bodies. The frame is modeled by the finite element method. Three torsional modes and three bending modes of the frame are considered for the interface of the heavy truck's computational model. The actual vehicle test is conducted off road with a velocity of 20km/h. The vertical accelerations at the cab and front axle are measured in the test. For the verification of the developed computational model, the measured vertical acceleration profiles are compared with the simulation results of the heavy truck's flexible computational model. E grade irregular road profile of ISO is used as an excitation input in the simulation. The verified flexible computational model is used to compare the vibration characteristics of a front suspension system having a multi-leaf spring and that having a tapered leaf spring. The comparison results show that the front suspension having a tapered leaf spring has a higher vertical acceleration at the front axle but a lower vertical acceleration at the cab than the suspension system having a multi-leaf spring.

• 한국생산제조학회지
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• 제19권3호
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• pp.307-312
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• 2010

In this study, advanced computational technique for mechatronic analysis has been developed for the efficient design and test of typical machine tool models. Flexible multi-body dynamic (FMBD) analysis method combined with motion controller including control logics is used to simulate typical operation conditions. The present FMBD machine tool model is composed of flexible column structure, rigid body spindle, vertical motion guide (arm) and screw elements. Driving motor clement with rotating degree-of-freedom is interconnected and governed by the designed Matlab Simulink control logic, and then the position of the spindle is feedback into the control logic. It is practically shown from the results that the investigation of designed machine tools with controller can be effectively conducted and verified.

• 대한기계학회논문집
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• 제12권3호
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• pp.450-456
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• 1988

본 연구에서는 자동차의 동력학적 해석을 위한 특별프로그램을 만들어서 범용 프로그램인 DADS와 효율성을 비교해 보고자 한다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2001년도 봄 학술발표회 논문집
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• pp.489-494
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• 2001

This paper deals with a dynamic modeling of artillery system loaded by gun charge explosion during firing condition. Geometric and elastic gun data are used to modify a projectile interaction model. The maximum impact force on gun barrel was 15,000 N and the gun barrel moved about 1.3 m. A cannon bal] was presented to travel in the flexible gun, the traveling distance was about 23,000 m, and the angular velocity was about 10rad/sec. The artillery dynamic system using the multi-body dynamics enables us to obtain the data for the fatigue analysis.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2003년도 추계학술대회
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• pp.390-395
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• 2003

Moving flexible structures such as transfer systems in press machine, crane, working table of machine tools have vibration problems because of starting, feeding and stopping. An analysis method is suggested and experimentally studied in order to solve a vibration problem of a moving flexible structure. In this method, the concepts of substructure synthesis method and semi-static displacement including rigid body mode were used. Total deformation of a structure was assumed to be composed of quasi-static and dynamic components. Experimental results from an elementary model of a transfer feeder showed good agreements with computational results.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2006년도 추계 학술대회논문집
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• pp.66-69
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• 2006

In the present study, we propose a virtual boundary method for simulation of massive inextensible flexible strings immersed in viscous fluid flow. The fluid motion is governed by the Navier-Stokes equations and a momentum forcing is added in order to bring the fluid to move at the same velocity with the immersed surface. A massive inextensible flexible string model is described by another set of equations with an additional momentum forcing which is a result of the fluid viscosity and the pressure difference across the string. The momentum forcing is calculated by a feedback loop. Simulations of several numerical examples are carried out, inlcuding a hanging string which starts moving under gravity without ambient fluid, a string swimming within a uniform flow and a uniform flow over two side-by side strings. The numerical results agree well with the theoretical analysis and previous experimental observations. Preliminary results of a swimming elongated fishlike body will also be presented.

• 한국해양학회지:바다
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• 제13권3호
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• pp.237-245
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• 2008

우리는 해저 연약지반 주행차량과 주행차량의 상부에 결합되어 있는 유연관의 연성거동 동력학 해석 기법을 개발하였다. 연약지반 주행차량은 1개의 강체로 모델링되었으며, 질량집중매개변수 기법을 이용한 이산화기법을 적용하여 유연관을 모델링하였다. 강체 무한궤도 주행차량의 운동방정식과 유연관의 3차원 비선형 지배방정식을 결합시켰으며, 4개의 오일러 매개변수를 이용하여 주행차량과 유연관의 자세를 표현하였다. 주행차량과 유연관의 비선형 연성거동 동력학 방정식의 해를 구하기 위해, 증분-반복법을 이용하였다. 시간영역 수치적분을 위해 $Newmark-\beta$기법을 이용하였다. 증분-반복법을 적용하여 연성 운동방정식에 대한 자코비안 행렬을 유도하였다. 동적거동 동력학 해석 기법을 통해 유연관의 동적거동과 연약지반 위를 주행하는 무한궤도 차량의 동적거동 사이의 상호작용을 시간영역에서의 관찰하였다.

• 한국전산구조공학회논문집
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• 제27권5호
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• pp.379-384
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• 2014

본 논문은 갠트리 크레인의 설계를 위해 컨테이너 하역작업 시 특정하중 조건하의 RTGC(Rubber Tired Gantry Crane)의 동적거동과 그에 따른 윤하중을 분석한 내용을 기술하고 있다. 먼저 RTGC의 동적거동을 살펴보기 위해 거대 구조물인 크레인의 유한요소 모델을 개발하고 고유진동수와 고유모드의 모달시험결과를 이용하여 유한요소모델을 검증하였다. RTGC의 기타 부속품은 3차원 CAD모델링을 통해 다물체 동역학해석 소프트웨어인 ADAMS에서 강체로 모델링하였다. 본 연구에서 하중 조건은 일반적인 컨테이너의 이송조건(OP1)과 외부부하조건 없이 단순히 트롤리를 이용하여 컨테이너를 하역하는 2가지 경우로 고려하였다. 해석 결과 RTGC의 컨테이너 작업 시 발생하는 크레인의 진동은 거대 구조물의 강성과 변형에 주로 기인함을 확인하였으며 이러한 크레인의 진동은 RTGC의 움직임을 발생시켜 컨테이너 하역작업 불능 등의 거동을 발생시킬 수 있음을 분석할 수 있었다.

• 대한기계학회논문집
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• 제18권6호
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• pp.1503-1509
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• 1994

An analysis method is suggested and experimentally studied in order to solve a vibration problem of a flexible structure while it is moving. In this method, substructure synthesis method, modal analysis method and Newmark's integral method were used. Total deformation of a structure was composed of quasistatic component and dynamic component. Rigid body modes were considered in calculation of dynamic component. Combining those two component, deformation behavior and a real structural model of a transfer feeder showed good agreements with computational results.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.147-150
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• 2005

The torsion beam axle type is widely used in the rear suspension for small passenger car because of low cost, good performance and etc. The FE and dynamic analysis using the computer are very helpful for the efficiency of the torsion beam design. First of all, the reliability on the computational model must be verified for the analysis. In this study, The FE model of the torsion beam was verified according to comparison with he test data. And after making the flexible body using the FE model, the dynamic characteristic of the tubular type torsion beam axles was compared with that of the V-beam type.