재료비선형 전달행렬법에 의한 연속보의 해석

서현수,김진섭,권민호 한국구조물진단유지관리공학회 2011 한국구조물진단유지관리공학회 논문집 Vol.15 No.1

연속보를 대상으로 한 재료비선형 전달행렬법을 제시하였으며, Gauss-Lobatto 적분법을 사용하여 보의 강성행렬로부터 전달행렬을 도출한다. 전달행렬법에서는 유한요소해석법과는 달리 각 절점의 자유도 수에 상관없이 일정한 미지값만을 가지게 되므로 선형해석뿐만 아니라 비선형해석에서도 빠른 연산속도를 보인다. 연속보에 대한 비선형 해석의 적용 예를 통한 비교 결과, 재료비선형 전달행렬법이 변위-모멘트, 변위-하중, 곡률-모멘트의 관계에서 유한요소해석법에 비해 효율적인 것으로 평가되었다. This study is to develop nonlinear analysis algorithm for transfer matrix method, which can be applied to continuous beam analysis. Gauss-Lobatto integral rule is adopted and the transfer matrix is derived from stiffness matrix. In the transfer matrix method, the system equation has a constant number of unknowns regardless of number of D.O.F. Therefore, the transfer matrix method has computational efficiencies not only in linear elastic analysis but also in nonlinear analysis. To verify the developed method, the analysis results of several examples are compared with commercial code in moment-curvature, moment-displacement and load-displacement relation.

전달행렬법에 의한 변단면 곡선 상자형 거더교의 정적해석

김용희 ( Kim Yong-hee ),이윤영 ( Lee Yoon-young ) 한국구조물진단유지관리공학회 2003 한국구조물진단유지관리공학회 논문집 Vol.7 No.4

근래에 와서 도로교량의 형식 선정에서 미관에 대한 고려가 더욱 더 강조되는 추세 있으며, 미적으로 뛰어난 곡선교의 가설이 자연적으로 선호된다. 전달행렬법은 이론의 체계가 알기 쉽고, 응용범위가 넓은 점에서 구조해석법으로 범용성이 있는 것으로 주목되어 왔다. 전달행렬법에 의한 변단면 곡선 상자형교의 정적해석을 유한요소법과 비교하여 잘 일치함으로써 프로그램의 타당성을 검증하였다. 곡률반경과 중심각에 따른 해석 및 변단면 곡선식에 따른 지간비를 구하여 최적지간비와 변단면 비를 순수비틀이론에 의한 해석치를 분석하였다. The state-of-art of curved box girder bridge with cross section design has advanced in various area. In these days, several analytical techniques for behaviors of curved box girder bridges cross section are available to engineers. The transfer matrix method is extensively used for the structural analysis because its merit in the theoretical background and applicability. The technique is attractive for implementation on a numerical solution by means of a computer program coded in Fortran language with a few elements. To demonstrate this fact, it gives good results which compare well with finite element method. Therefore, this paper proposed the static analysis method of curved box bridge with cross section by transfer matrix method based on pure-torsional theory and the optimal span ratio /variable cross section ratio of 3 span continuous curved box girder bridge.

Numerical Stability of the Transfer Matrix Method Based on Transcendental Functions for Vibration Analyses of the Structures

Jung Woo Lee(이정우),Chan U Jo(조찬우),Joon Seong Lee(이준성),Jung Youn Lee(이정윤) 한국소음진동공학회 2017 한국소음진동공학회 논문집 Vol.27 No.6

This study analyzes the cause of three numerical instabilities for the transfer matrix method (TMM) by controlling the precision of the arbitrary digits in the numerical device as follows: (1) the missing natural frequency, (2) the inaccurate results, and (3) the computational difficulty of the high-order natural frequency. Two types of TMMs are examined. One TMM is composed of the trigonometric and hyperbolic functions (4×4 TMM) for the transverse vibration of a straight beam, and the other is composed of exponential functions (8×8 TMM) for the coupled bending vibrations of a twisted beam. TMMs with numerical stability can obtain the eigenpairs of over 220 up to the overflow (2<SUP>1024</SUP>) in the numerical device. The explicit range capable of computing the eigenpairs using the 4×4 and 8×8 TMMs without any modifications is proposed in the analyzed results.

유한요소-전달행렬법에 의한 스크롤 압축기 크랭크축의 과도 동적 해석

김태종 한국소음진동공학회 2000 소음 진동 Vol.10 No.1

The dynamic behavior of crankshaft-bearing system in scroll compressor has been investigated using the combined methodologies of finite elements and transfer matrices. The finite element formulation is proposed including the field element for a shaft section and the point element at balancer weight locations, bearing locations, etc., whereas the conventional method is used with the elements. The Houbolt method is used to consider the time march for the integration of the system equations. The linear stiffness and damping coefficients are calculated for a finite cylindrical fluid-film bearing by solving the Reynolds equation, using finite difference method. The orbital response of crankshaft supported on the linear bearing model is obtained, considering balancer weights of motor rotor. And, the steady state displacement of crankshaft are compared with a variation in balancer weight. The loci of crankshaft at bearing locations are composed of the synchronous whirl component and the non-synchronous whirl component.

전달행렬법을 이용하여 비틀림 각과 회전관성을 고려한 보의 진동해석

이정윤(Jung Youn Lee) 한국소음진동공학회 2016 한국소음진동공학회 논문집 Vol.26 No.2

In this study, a transfer matrix method (TMM) for a twisted uniform beam considering the effect of rotary inertia is developed, and the differential equation and the displacements and forces are derived from Hamilton’s principle. The particular transfer matrix is derived by applying the distributed mass and transcendental function while using a local coordinate system. In addition, the results obtained from this method are independent for a number of subdivided elements, and this method can determine the exact solutions for the free vibration characteristics of a twisted uniform Rayleigh beam. To validate the accuracy of the proposed TMM, the computed results are compared with those reported in the existing literature, and the comparison results indicate notably good agreement. In addition, the method is used to investigate the effects of rotary inertia for a twisted beam.

전달행렬법을 사용하여 균열이 있는 티모센코 보의 동특성 해석

김정호(Jung Ho Kim),곽종훈(Jong Hoon Kwak),이정우(Jung Woo Lee),이정윤(Jung Youn Lee) 한국소음진동공학회 2016 한국소음진동공학회 논문집 Vol.26 No.2

This paper presents a numerical method that can evaluate the effect of crack for the in-plane bending vibration of Timoshenko beam. The method is a transfer matrix method that the element transfer matrix is deduced from the element dynamic stiffness matrix. An edge crack is expressed as a rotational spring, and then is formulated as an independent transfer matrix. To demonstrate the accuracy of this theory, the results computed from the present are compared with those obtained from the commercial finite element analysis program. Based on these comparison results, a parametric study is performed to analyze the effects for the size and locations of crack.

전달행렬법을 이용한 다중 다공판 시스템의 흡음성능 예측

이동훈,허성춘,권영필 한국소음진동공학회 2002 한국소음진동공학회 논문집 Vol.12 No.9

A practical method of predicting the sound absorption coefficient for multiple perforated-plate sound absorbing system was developed using transfer matrix method. The proposed method was validated by comparing the calculated absorption coefficients of a single layer perforated plate with the values measured by the two-microphone impedance tube method for various porosity and spacing of the perforated plate. The developed transfer matrix method was further applied to estimate the multiple layer perforated plates and it is shown that the estimated absorption coefficients agree well with the measured values.

전달행렬법을 이용하여 지반진동을 받는 전단구조물의 응답해석

조찬우(Chan U Jo),이준성(Joon-Seong Lee),이정윤(Jung Youn Lee) 한국소음진동공학회 2018 한국소음진동공학회 논문집 Vol.28 No.5

Shear story structures are widely used in industrial equipment structure and building design but are often vibrated during the vibration of the ground. Ground vibration is caused by many variables such as earthquake, mechanical vibration, vehicle and human steps. As a result, a study on the vibrational response of this type of structure is important to both accuracy product and future building designs. Traditionally, finite element methods such as the ANSYS and MIDAS have been used as the primary methods of computing the response of such a structure. However, these methods yield low calculation efficiencies. In this paper, the mechanical model of a four-story shear structures is constructed based on the expanded transfer matrix method. The expanded transfer matrix of the components in the model and the total transfer matrix equation of the structure are derived, and the corresponding MATLAB program is compiled to determine the natural frequencies and response of the structure. The results of the transfer matrix are in good agreement with the results of the modal analysis.

전달행렬법에 의한 곡선거더교의 비틀림 응력비와 비틀림 정수비에 관한 연구

이원홍,이윤영 한국구조물진단유지관리공학회 2006 한국구조물진단유지관리공학회 논문집 Vol.10 No.1

곡선거더교의 설계에서 I형 병렬, 1박스, 2박스의 거더 형태의 교량은 횡과 비틀림을 동시에 발생함으로 그 응력은 매우 복잡하다. 일반적으로 비틀림은 순수 비틀림과 횡 비틀림으로 구성되어 있으므로 곡선거더교의 발생되는 응력들을 결정하는 절차는 매우 어렵다. 전달행렬법은 이론적인 배경과 적용이 매우 쉬운 장점 때문에 구조해석 분야에서 많이 사용되고 있으며. 유한차분법과 비교하여 신뢰성을 검증하여 좋은 결과를 얻었다. 따라서, 본 연구에서는 I형 병렬 곡선교, 1박스거더 곡선교, 2박스 거더 곡선교에 대한 비틀림 정수비와 비틀림 의한 비틀림 응력비 사이 관계를 비교 검토하여 휭 비틀림에 의한 응력해석을 생략할 수 있는 비틀림 정수비의 한계 값을 분석하였다. In the design of curved girder bridges, the engineer is faced with a complex stress situatiorl. since these types of mutiple-I girder. mono-box girder and twin-box girder are subjected to both bending and torsional force. In general, the torsional forces consist of two part, St. venant's and warping. Thus the procedure for determining the induced stresses in a curved girder is difficult. The transfer matrix method is extensively used for the structural analysis because its merit in the theoretical background and applicability. The technique is attractive for implementation on a numerical solution by means of a computer program coded in Fortran language with a few elements. To demonstrate this fact. it gives good results which compare well with finite difference method. Therefore, in this paper, to clarify the range where the torsional warping stress can be approximated by pure torsional analyzed a critical value of relationships between the torsional stress ratio and torsional ratio.

점성댐퍼를 갖는 엔진 크랭크 축계의 비틀림 진동 해석

송오섭(Ohseop Song),박상윤(Sang-Yun Park),김선홍(Sunhong Kim) 한국소음진동공학회 2015 한국소음진동공학회 학술대회논문집 Vol.2015 No.4

In this study, the torsional vibration analysis for the marine propulsion system is carried out by using the transfer matrix method(TMM). The torsional torque by gas pressure and reciprocating inertia force is caused severe torsional vibration in the shafting, which is damage to the shaft. normal torque and many harmonic torque are applied to the crankshaft and rotate the shafting. In four stroke cycle, if the cycle of the n-harmonic torque matches the natural frequency of the shaft, the torsional vibration of n/2-order is generated. In general, as a method for controlling the torsional vibration, there are various ways to change natural frequency due to the shaft diameter and the inertia moment adjustment and to reduce excitation force by firing order and crank arrangement and to lower the vibration energy by torsional vibration damper. In this paper, the viscous damper is used for reducing the torsional vibration of shafting as torsional vibration damper and it was confirmed damping effect of the torsional vibration.