• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.05a
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• pp.421-422
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• 2010

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.6
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• pp.585-592
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• 2014

In this study, a multibody simulator was developed to analyze the bio-mimetic motion of a lizard robot design. A RecurDyn multibody dynamics model of a lizard was created using a micro-computerized tomography scan and motion capture data. The bio-mimetic motion simulator consisted of a trajectory generator, an inverse kinematics module, and an inverse dynamics module, which were used for various walking motion analyses of the developed lizard model. The trajectory generation module produces spinal movements and gait trajectories based on the lizard's speed. Using the joint angle history from an inverse kinematic analysis, an inverse dynamic analysis can be carried out, and the required joint torques can be obtained for the lizard robot design. In order to investigate the effectiveness of the developed simulator, the required joint torques of the model were calculated using the simulator.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.6
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• pp.14-22
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• 2010

In this study, a large bus is tested for measuring the steering response based on the slarom test and step steer test. A full car model by using ADAMS/Car is established for computer simulation. For bus modeling, user defined templates are made and used in the simulation. Simulation results according to the slarom and step steer test are compared to the physical experiments, in which several sensors are installed to measure vehicle responses. The results obtained from the comparison show a good agreement with regard to the vehicle velocity and steering angle.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.3
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• pp.73-79
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• 2010

A preliminary study on a length-variable rotor blade for a small unmanned helicopter has been conducted. After surveys on previous researches, and examining requirements for application to a small unmanned helicopter, a length-variable rotor blade was designed and manufactured to be driven by centrifugal force from rotor revolution with no mechanical actuator. The rotor blade was divided into a fixed inboard section and an outboard section sliding in span-wise direction. In order to determine the operating conditions of the length-variable rotor during revolution, and to derive the design variables of extension spring and rotor weight, a series of analyses from multi-body dynamics solution were conducted. The manufactured prototype was verified of its length-varying mechanism from a rotor stand, the results and required future improvements are discussed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.2
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• pp.115-120
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• 2014

In this study, a module is developed for modeling and analyzing dynamic behavior of a wind turbine using RecurDyn, which is a commercial multi-body dynamics software developed by FunctionBay, Inc. The wind turbine consists of tower, nacelle, hub and blades. Tower and blades are regarded as flexible bodies for considering elastic effect using beam theory and spring force. In this paper, a constant speed wind was assumed and aerodynamic force is modeled using BEM theory. Dynamic analysis applying this aerodynamic force is carried out. To verify the validity of analysis results, these results are compared to those of GH-Bladed which is a commercial software for analyzing wind turbine system distributed by Garrad Hassan.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.4
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• pp.56-61
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• 2019

In this country, mackerel landing, sorting, and packing are mostly performed manually, which is time consuming and labor intensive. An unloading automation system saves time and labor by automating the landing, sorting, and packing processes. Casers are devices for manufacturing packing boxes for fish used by unloading automation systems. The caser design in this study is for mackerel packing boxes. This caser makes a packing box based on a press using the caser's slide crank. When the caser makes a packing box, the manufacturing sequence is determined by the caser's production guide and assisting rod. The caser design in this study is simulated using a multi-body dynamics program. The simulation is used to analyze the caser and to visualize the box-making sequence.

• Journal of Ocean Engineering and Technology
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• v.29 no.2
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• pp.120-127
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• 2015

When a deep-seabed lifting pump is kept this device has bending and deformation in the axis due to its long length(8m). These influences can be caused a breakdown. Therefore, a mounting must be developed to keep the lifting pump safe. This paper discusses the hydraulic cylinder design of the lifting pump and structural safety estimation of the mounting using SBD(simulation-based design). The multi-body dynamic simulation method is used, which has been used in the automotive, structural, ship building, and robotics industries. In this study, the position and diameter of the hydraulic cylinder were determined based on the results of the strokes and buckling loads for the design positions of the hydraulic cylinder. A structural dynamic model of the mounting system was constructed using the determined design values, and the structural safety was evaluated using this dynamic model. According to these results, this system has a sufficient safety factor to manufacture.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.9
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• pp.4142-4148
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• 2013

Because of effective fruit growing and management in the slope land, the use of orchard vehicle with lifting utilities has been increased. For this reason the study on the stability of that vehicle for worker's safety is needed. This study is investigated on the stability estimation of orchard vehicle with four wheels and dual rectangular-type lifting utilities which can be moved on the dirt sloping load. Through the multi-body dynamics analysis on the vehicle mechanism, overturning angles of 19.2 and $34.6^{\circ}$ in the right-left and front-rear direction can be calculated. It is determined tractive resistances and required powers of the wheels. And through the finite element analysis on the frame of lifting utility its maximum von-Mises stress is 146 MPa and it is structural stable. Therefore it is known that the orchard vehicle with wheels and lifting utilities has static and dynamic stability.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.3
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• pp.26-32
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• 2019

This study was conducted to analyze the stresses by impact loads on front-end loaders attached to tractors using flexible multi-body dynamics. The model was designed and validated by comparing previous experimental data with the simulation data obtained in this study. Nine sets of conditions were designed using three weights (500, 300, and 100 kg) loaded inside a bucket and three heights (1700, 1350, and 1000 mm) of the bucket from ground level. A parametric study was carried out at five locations for two types of parts of a front-end loader. All the safety factors for the five locations under all conditions were calculated and were greater than 1. Thus, the designs of the front-end loaders were structurally safe. Based on this study, front-end loaders attached to tractors can be designed effectively in terms of cost and safety.

• Journal of Drive and Control
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• v.21 no.1
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• pp.22-30
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• 2024

Gearboxes designed for reciprocating motion operating mechanisms operate under conditions where both the load and speed undergo continuous variations. When conducting durability tests on gearboxes designed for such applications, operating the target gearbox under conditions similar to the intended usage is essential. The gearbox must be operated for the required number of cycles to validate its durability under conditions mirroring its intended usage. This study devised an accelerated test method for gearboxes, which reduces operating angles and operational strokes. The reliability of the accelerated test was verified by comparing the stresses imposed on the gears under general and acceleration conditions through multi-body dynamic simulations. The results confirmed that the maximum contact stress levels under normal and accelerated conditions were within a 0.1% error range, indicating a minimal difference in the gear damage rates. However, a difference in the maximum contact stress results between the normal and accelerated conditions was observed when inertial forces acted on the output shaft due to the operational acceleration of the gearbox. Therefore, when conducting this acceleration test, caution should be exercised to ensure that the operational load on the gearbox, which affects inertia, does not significantly deviate from the conditions observed under normal operating conditions.