• 한국철도학회논문집
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• 제14권1호
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• pp.11-18
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• 2011

본 논문은 열차의 타고오름 해석을 위한 새로운 2차원 다물체 동역학 모델링 방법을 제안하였다. 본 동역학 모델은 에너지 흡수구조/부품뿐만 아니라 차체의 변형도 고려하여 비선형 스프링, 댐퍼, 질량으로 구성되며 철도차량의 충돌에너지흡수량, 승객구간의 가속도, 연결 장치의 충격력, 차량간 타고오름 변위 등을 잘 예측할 수 있다. 제안된 방법으로 한국형고속열차를 차체 각 부분의 압괴 특성을 구하고 2차원 다물체 충돌동역학 모델을 구성하였다. 열차 대 열차 충돌 시나리오조건으로 2차원 동역학 모델을 시뮬레이션하고 3차원 가상시험 모델로 평가하였다. 그 결과 2차원 동역학 모델은 타고오름 거동을 잘 예측하였으며 차체변형을 고려한 모델링 기법이 타고오름 평가에 중요함을 확인하였다.

• 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.

• Ocean Systems Engineering
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• 제13권4호
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• pp.349-365
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• 2023

Targeting a floating wave and offshore wind hybrid power generation system (FWWHybrid) designed in the Republic of Korea, this study examines the impact of the interaction, with multiple wave energy converters (WECs) placed on the platform, on platform motion. To investigate how the motion of WECs affects the behavior of the FWWHybrid platform, it was numerically compared with a scenario involving a 'single-body' system, where multiple WECs are constrained to the platform. In the case of FWWHybrid, because the platform and multiple WECs move in response to waves simultaneously as a 'multi-body' system, hydrodynamic interactions between these entities come into play. Additionally, the power take-off (PTO) mechanism between the platform and individual WECs is introduced for power production. First, the hydrostatic/dynamic coefficients required for numerical analysis were calculated in the frequency domain and then used in the time domain analysis. These simulations are performed using the extended HARP/CHARM3D code developed from previous studies. By conducting regular wave simulations, the response amplitude operator (RAO) for the platform of both single-body and multi-body scenarios was derived and subsequently compared. Next, to ascertain the difference in response in the real sea environment, this study also includes an analysis of irregular waves. As the floating body maintains its position through connection to a catenary mooring line, the impact of the slowly varying wave drift load cannot be disregarded. To assess the influence of the 2^nd-order wave exciting load, irregular wave simulations were conducted, dividing them into cases where it was not considered and cases where it was included. The analysis of multi-degree-of-freedom behavior confirmed that the action of multiple WECs had a substantial impact on the platform's response.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.188-193
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• 2007

Airport railroad have required maximum design speed 120km/h and wind speed 50m/s condition as design item of airport railroad vehicles. To design and manufacture the vehicle satisfying these conditions, it must carry out the dynamic behaviors analysis such as hunting stability, ride comfort derailment ratio, unloading ratio and lateral force to meet the criterion described in Urban Railroad Act. Dynamic behaviors of vehicle have carried out using the multi-body dynamics simulation program(VAMPIRE). This paper presents the evaluation methods and criterion used to verify dynamic performance of airport railroad vehicle, and show the analysis results of vehicle dynamic simulation and the test results for vibration and ride comfort measured on running performance tests. As a results, each analysis results and test results meet the criterion described in Urban Railroad Act.

• 대한기계학회논문집A
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• 제32권10호
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• pp.882-889
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• 2008

A humanoid is a robot with its overall appearance based on that of the human body. When the humanoid moves or walks, dynamic forces act on the body structure. Although the humanoid keeps the balance by using a precise control, the dynamic forces generate unexpected deformation or vibration and cause difficulties on the control. Generally, the structure of the humanoid is designed by the designer's experience and intuition. Then the structure can be excessively heavy or fragile. A humanoid design scenario for a systematic design is proposed to reduce the weight of the structure while sufficient strength is kept. Lower parts of the humanoid are selected to apply the proposed design scenario. Multi-body dynamics is employed to calculate the external dynamic forces on the parts and structural optimization is carried out to design the lower parts. Because structural optimization using dynamic forces directly is fairly difficult, linear dynamic response structural optimization using equivalent static loads is utilized. Topology and shape optimizations are adopted for two steps of initial and detailed designs, respectively. Various commercial software systems are used for analysis and optimization. Improved designs are obtained and the design results are discussed.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.711-716
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• 2003

This paper presents the inverse dynamic analysis of the hydraulic excavator manipulator based on the experimental data. A three dimensional rigid multi-body model of the hydraulic excavator manipulator was built up. Inverse dynamic analysis for typical operation mode was carried out by the ADAMS program. In order to verify the analysis results with the measured, the hydraulic pressure and displacement of the cylinders were measured and the dynamic analysis was carried out using experimental data. From the results of the cylinder driving forces, good agreements are obtained between the analysis and the measurement.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.881-886
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• 2004

This paper presents the inverse dynamic analysis of the wheel loader manipulator based on the experimental data. A three dimensional rigid multi-body model of the wheel loader manipulator was built up. The inverse dynamic analysis for the typical operation mode was carried out by the ADAMS program. In order to verify the analysis result with the measured one, the hydraulic pressure and displacements of the cylinders were measured and the inverse dynamic analysis was carried out using experimental data. From the results of the analysis and measurement, it was concluded that the computational driving force showed good agreement with the measured one.

• 한국산학기술학회논문지
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• 제14권9호
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• pp.4142-4148
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• 2013

경사지 과수의 효율적인 재배 및 관리를 위해 과수원 전용 고소 작업차량 사용이 늘어나고 있다. 이러한 이유로 작업자 안전을 위해 고소 작업차의 안정성에 대해 연구가 요구되고 있다. 본 연구는 경사지 흙길을 주행할 수 있는 4개의 바퀴와 2개의 직교 좌표계 적재함을 가진 과수원 차량의 안정성 평가에 대한 연구이다. 차량 메커니즘에 대한 다물체 동역학(MBD) 해석을 통하여 19.2, $34.6^{\circ}$의 좌우 및 상하 방향의 전복각을 계산할 수 있었다. 바퀴들의 주행 저항과 소요 동력을 결정하였다. 그리고 적재함 프레임의 유한요소해석(FEA)를 통하여 최대응력 146 MPa로 구조적으로 안정하다. 따라서 적재함을 가진 바퀴형 과수원 차량은 정적 및 동적 안정성을 가짐을 알 수 있었다.

• 대한기계학회논문집A
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• 제38권2호
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• pp.115-120
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• 2014

본 연구에서는 다물체 동역학 해석 소프트웨어인 RecurDyn 을 이용하여 풍력 발전기를 쉽게 모델링하고 동적 거동 해석을 수행할 수 있는 기법을 개발하였다. 풍력 발전기는 타워, 너셀, 허브, 그리고 블레이드로 구성되어 있다. 타워와 블레이드는 탄성체로 가정하였고 탄성효과를 고려하기 위하여 탄성체 이론을 이용하여 모델링 하였다. 바람의 속도는 일정하다고 가정하였고 날개 요소 운동량 이론을 이용하여 공력하중을 모델링 하였다. 이를 통해 계산된 공력을 풍력 발전기에 적용시키고 동적 거동 해석을 수행하였다. 해석의 타당성을 검증하기 위하여 풍력 발전 시스템 상용 소프트웨어인 GH-Bladed를 이용한 해석결과와 비교하였다.

• 한국소음진동공학회논문집
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• 제22권9호
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• pp.889-895
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• 2012

A vertical launching system(VLS) is a system for holding and firing missiles on surface ships. When a missile is launched in VLS, relative motion between canister and missile and drag force induced by wind can cause initial unstability of a missile. Thus dynamic analysis of initial behavior of vertically launched missile should be performed to prevent collision with any structure of a ship. In this study, dynamic analyses of initial behavior of vertically launched missile are performed using Monte-Carlo simulation, which relys on random sampling and probabilistic distribution of variables. Each parameter related with dynamic behavior of a missile is modeled with probability variables and Recurdyn, a commercial software for multi body dynamic analysis, is used to perform Monte-Carlo simulation. As a result, initial behavior of a missile is evaluated with respect to various performance indexes in a probabilistic sense and sensitivity of the each parameters is calculated.