• 대한기계학회논문집A
• /
• 제38권6호
• /
• pp.691-698
• /
• 2014

본 논문에서는 복합재료를 이용하여 플렉스빔과 토크튜브를 제작하기 위한 공정과 기본 물리량 시험과정을 소개하였다. 플렉스빔과 토크튜브는 헬리콥터에 적용되는 무베어링 로터 허브 시스템을 구성하기 위한 핵심 구성품이다. 토크튜브는 블레이드의 피치각을 변화시키기 위한 조종력을 전달하며, 플렉스빔은 구조적인 변형을 통해 플랩, 래그 및 페더링 힌지를 구현하는 기능을 담당한다. 지상회전시험을 수행하기에 앞서 플렉스빔과 토크튜브 및 블레이드의 플랩강성, 래그강성 및 토션강성을 측정하기 위한 기본 물리량 시험을 수행하였다. 또한, 해석을 통해 예측된 단면 강성과 기본 물리량을 통해 획득된 강성 값을 비교하였으며, 그 결과를 통해 복합재료로 제작된 플렉스빔과 토크튜브가 구조적인 강성 요구도를 만족함을 확인할 수 있었다.

• Wind and Structures
• /
• 제32권2호
• /
• pp.169-177
• /
• 2021

This study investigates the effects of blade configuration and solidity of Darrieus wind turbine on the starting torque characteristics. Generally, the configuration of Darrieus wind turbine is divided into Troposkien, parabola, Catenary, Sandia, modified-parabola and straight types. A numerical analysis has been carried out using Multiple Stream Tube (MST) method to investigate the effect of blade configuration and solidity of Darrieus wind turbine on the starting torque under the initial low range of rotational speed. The simulation results show that the starting torque of Darrieus wind turbine varies considerably depending on the blade configuration. The initial starting torque was larger with Troposkien, Parabola, Catenary, and Sandia configurations than with modified parabola or straight types. The increase in solidity with increasing number of blades raised the starting torque and improved the dynamic stability during the initial operational speed of Darrieus wind turbine. Additionally, these torque results represent basic data for fluid-structure interaction (FSI) simulation of the steady-dynamic operation of the turbine.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2011년도 추계학술대회 논문집
• /
• pp.52-56
• /
• 2011

Recently, KARI(Korea Aerospace Research Institute) has been developing a modern 11.5m diameter four bladed bearingless main rotor system, and this rotor system can be used for 7,000lb class helicopter. Flexbeam and torque tube can be considered as the key structural components, and large elastic twist of flexbeam induced by pitch control motion of torque tube can influence the nonlinear aeroelastic behavior. In this paper, the dynamic characteristic analysis results of bearingless rotor system were presented. In order to construct a input model and validate the analysis procedures, calculated results using the comprehensive helicopter analysis program CAMRAD II were compared with the measured natural frequencies and lag damping data from small-scale wind tunnel test. Next, the analysis model was extended to a full-scale model, and the dynamic analysis results were presented.

• 한국소음진동공학회논문집
• /
• 제22권2호
• /
• pp.187-192
• /
• 2012

Recently, KARI(Korea Aerospace Research Institute) has been developing a modern 11.5 m diameter four bladed bearingless main rotor system, and this rotor system can be used for 7,000 lb class helicopter. Flexbeam and torque tube can be considered as key structural components, and large elastic twist of flexbeam induced by pitch control motion of torque tube can influence the nonlinear aeroelastic behavior. In this paper, the dynamic characteristic analysis results of bearingless rotor system were presented. In order to construct a input model and validate the analysis procedures, calculated results using the comprehensive helicopter analysis program CAMRAD II were compared with the measured natural frequencies and lag damping data from small-scale wind tunnel test. Next, the analysis model was extended to a full-scale model, and the dynamic analysis results were presented.

• 대한기계학회논문집A
• /
• 제34권8호
• /
• pp.1083-1089
• /
• 2010

형상기억합금은 지능형 재료와 구조물에 널리 쓰인다. 큰 힘과 변위를 발생시키는 것이 특징이며 작동기, 소음 및 진동감쇠, 동역학적 튜닝, 형상의 변형 제어 등의 다양한 분야에 응용될 수 있다. 본 논문에 서는 형상기억합금튜브와 초탄성 스프링으로 구성된 형상기억합금 비틀림 작동기를 제안하였고 각각의 거동 특성을 알아보았다. 열전달 해석을 통해 저항열과 히터의 열을 동시에 형상기억합금튜브에 가하면 작동기의 성능을 더 향상시킬 수 있음을 확인하였다. 접촉 해석으로는 실제 작동기의 거동을 시뮬레이션하였고 정상적으로 작동함을 알 수 있었다. 3 차원 형상기억합금의 거동을 표현하기 위해 비선형 구성방정식을 유한요소 법으로 풀고 ABAQUS 의 U-MAT 기능을 이용하여 비선형 해석을 수행하였다.

• 한국산학기술학회논문지
• /
• 제12권12호
• /
• pp.5393-5397
• /
• 2011

본 연구는 나노튜브 제조시스템의 주요 구성요소인 압축-절단 장치가 안전한 성능을 발휘할 수 있도록 설계하는데 목적이 있다. 나노튜브의 제조에 있어서 가장 중요한 핵심기술은 튜브에 나노물질을 주입한 후 압력을 가하여 안전하게 봉합하고 전단분리 하는 것이다. 이 때 작용하는 압력과 속도가 나노튜브의 품질을 결정한다. 본 연구에서는 DC서보모터에 의하여 구동되는 압축-절단 장치의 구동력을 설계하고 이를 바탕으로 시스템을 제작한 후 시제품을 생산하는 과정을 보이고자 한다.

• 한국기계가공학회지
• /
• 제17권4호
• /
• pp.32-38
• /
• 2018

In this study, the one-piece propeller shaft composed of carbon/epoxy was designed and manufactured for 4 wheel drive automobiles that can bear the target torsional torque performance of 3.5kN.m. For the CFRP tube, braiding machine was used to weaving carbon fiber and it was formed the braided yarns with the braid angle ${\pm}45^{\circ}$ and axial yarns to improve strength of the lengthwise direction. The final CFRP tube of propeller shaft was evaluated through the torsional torque test. The CFRP propeller shaft satisfied requirement of the target torsional maximum torque of 3.5kN.m. Also, it was found that the one-piece composite propeller shaft with CFRP tube had 30% weight saving effect compared with a two-piece steel propeller shaft.

• 소성∙가공
• /
• 제5권2호
• /
• pp.165-175
• /
• 1996

the process of strip twisting is practiced for the manufacture of some commercial parts such as elements for tube type line mixers. A thin metal strip with rectangular cross section is twisted thru an angle greater than 180。. Initial geometry is altered in to a complex one with dimen-sional changes. In practice several tryouts are necessary to obtain required dimensional accu-racies. A simple analysis model is proposed to predict the dimensional changes forming torque and axial force.

• International Journal of Aerospace System Engineering
• /
• 제4권1호
• /
• pp.13-21
• /
• 2017

In this paper, we present some results on performance analysis for flap actuation system of aircraft. For this, by utilizing MATLAB/Simulink solution, which is widely used physical model-based design tool, we particularly construct the architecture of the analysis model consisting of the main three phases: 1)commanding and outer-controlling the flap angle through flight control computer; 2)generating hydraulic/mechanical power through control module and power drive unit; 3)transmitting torque and actuating the flap through torque tube and rotary geared actuators. For mimicking the motion of the actual flap, we apply each mechanical component, which is already being used in actual aircraft, to our performance analysis model so that it guarantees the congruency of the simulation results. That is, we reflect the actual specifications of flap hardware and software as parameters of the model. Finally, simulation results are presented to illustrate the model.

• 대한기계학회논문집
• /
• 제17권10호
• /
• pp.2407-2417
• /
• 1993

Thermal deformations and stresses due to temperature changes are the serious problems in cryogenic structures such as the torque tube in a superconducting generator, In this paper, the equations of thermal expansion coefficients expressed only by material properties and winding angles are derived for the filament wound composite tubes. The experimental results of thermal contraction of CFRP tubes are compared with those from theoretical approach. Composite tubes with optimally regulated thermal expansion coefficient are designed on the basis of the study for the torque tube in the superconducting generator with temperature distributions varying from 300K to 4.2 K. The filament winding angle of composites resisting thermal stresses properly is sought by the finite element method using layered shell elements. The results show that the composite tubes designed for the requirements in cryogenic environments can effectively cope with the thermal stress problem.