• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(I)
• /
• pp.367-370
• /
• 2005

This study is to propose a truss model which is able to reasonably predict the shear strength of reinforced concrete (RC) members with high-strength materials. The shear strengths of 107 RC test beams with high-strength steel bars reported in the technical literatures were compared to those obtained from proposed model, TATM, and existing truss models. The shear strength of reinforced concrete beams obtained from test was better predicted by TATM than other truss models. Also, the theoretical results by TATM were almost constant regardless of yield strengths and steel ratios of tension and shear reinforcements.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2005년도 추계학술대회논문집
• /
• pp.612-615
• /
• 2005

This studies presented truss frame which use aluminum beam by damage model. Truss frame which each joint part is contracted by bolt contracted conclusion of each bolt by 3.0 N/m. And measured impedance change that appear making bolt 0.5 N/m on damage condition 8 times. Compares impedance change of 5 segments that was set by measurement area and displayed result. To measure torque change of bolt, other damage model did not apply.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2007년도 춘계학술대회 논문집
• /
• pp.262-265
• /
• 2007

Metallic sandwich plates constructed of two face sheets and low relative density cores have lightweight characteristics and various static and dynamic load bearing functions. To predict the formability and performance of these structured materials, a computationally efficient FE-analysis method incorporating virtual equivalent projected model has been newly introduced for analysis of metallic sandwich plates. Two dimensional models using the projected shapes of 3D structures have the same equivalent elastic-plastic properties with original geometries including anisotropic stiffness, yield strength and linear hardening function. The projected shapes and virtual properties of the virtual equivalent projected model have been estimated analytically with the same equivalent properties and face buckling strength of 3D pyramidal truss core.

• Structural Engineering and Mechanics
• /
• 제23권6호
• /
• pp.713-737
• /
• 2006

This paper presents the results of an experimental investigation on the behaviour of 56 reinforced concrete beams subjected to pure torsion. The reported results include the behaviour curves, the failure modes and the values of the pre-cracking torsional stiffness, the cracking and ultimate torsional moments and the corresponding twists. The influence of the volume of stirrups, the height to width ratios and the arrangement of longitudinal bars on the torsional behaviour is discussed. In order to describe the entire torsional behaviour of the tested beams, the combination of two different analytical models is used. The prediction of the elastic till the first cracking part is achieved using a smeared crack analysis for plain concrete in torsion, whereas for the description of the post-cracking response the softened truss model is used. A simple modification to the softened truss model to include the effect of confinement is also attempted. Calculated torsional behaviour of the tested beams and 21 beams available in the literature are compared with the experimental ones and a very good agreement is observed.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
• /
• pp.229-233
• /
• 2003

This paper describes a practical formulation of Non-Bernoulli-Compatibility Truss Model. Not only equilibrium conditions but also some approximations are employed to solve for the unknowns included in the proposed model. By assuming that the ratio of $V_a$ to V remains to be constant along the shear span, the relationship between $\alpha$ and z is mathematically established as an arch shape function. $V_m$ is also approximated to be an empirical value that is equal to the least membrane shear strength. The coefficient a is made utilizing a nonlinear finite element analysis. The adequacy of the model is examined by test results available in literatures, and the predicted values are shown to be in excellent agreement with the experimental results.

• 한국공간구조학회논문집
• /
• 제5권2호
• /
• pp.89-97
• /
• 2005

건축 구조물이 초고층화, 대형화, 특수화 되어감에 따라 고강도 재료의 사용이 증대되고 있으며, 고강도 재료가 사용된 철근콘크리트 보의 전단강도를 타당하게 예측할 수 있는 해석모델이 반드시 필요하다. 본 연구에서는 고강도 철근이 사용된 철근콘크리트 보의 전단강도를 타당하게 예측할 수 있는 트러스 모델을 제안한다. 고강도 철근이 사용된 철근콘크리트 보의 전단강도에 대한 제안된 모델인 TATM의 타당성을 검토하기 위하여 총 107개 보의 실험결과를 수집하였으며, TATM 및 기존 트러스 모델의 전단강도 해석결과를 이들 실험결과와 비교하였다. 비교 결과, TATM은 다른 트러스 모델보다 실험결과를 더 잘 예측하였으며, TATM의 해석결과에 대한 실험결과의 비는 인장철근과 전단 철근의 항복강도에 거의 관계없이 일정하였다.

• Structural Engineering and Mechanics
• /
• 제43권6호
• /
• pp.711-724
• /
• 2012

The goal of this study is to conceptually orientate optimized layouts of outrigger belt trusses which are in widespread use today in the design of tall buildings by strut-and-tie truss models utilizing a topology optimization method. In this study unknown strut-and-tie models are realized by using a typical SIMP method of topology optimization methods. In tradition strut-and-tie model designs find the appropriate strut-and-tie trusses along force paths with respect to elastic stress distribution, and then engineers or designers determine the most proper truss models by experience and intuition. It is linked to a trial-and-error procedure based on heuristic strategies. The presented strut-and tie model design by using SIMP provides that belt truss models are automatically and robustly produced by optimal layout information of struts-and-ties conforming to force paths without any trial-and-error. Numerical applications are studied to verify that outrigger belt trusses for tall buildings are optimally chosen by the proposed method for both static and dynamic responses.

• 한국농공학회논문집
• /
• 제57권6호
• /
• pp.59-68
• /
• 2015

Traditional structure analysis method is based on numerical matrix analysis to use the geometries consisting of the structure. The characteristics require a lot of computer memories and computational time. To avoid these weaknesses, new approach to analyze truss structure was suggested by adopting topological load redistribution method. The axial forces to be not structurely analyzed yet against outside loads were redistributed by using nodal equation of equilibrium randomly at each node without constructing global matrix. However, this method could not calculate the axial forces if structure is statically indeterminate due to degree of many indeterminacies. Therefore, to apply the method suggested in this research, all redundancies of truss structure were replaced by unit loads. Each unit load could make the deformation of a whole structure, and a superposition method was finally adopted to solve the simultaneous equations. The axial forces and deflections agreed with the result of commercial software within the relative error of 1 %, whereas in the case that the axial forces are relatively very smaller than others, the relative errors were increased to 2 %. However, as the values were small enough not to be considered, it was practically useful as a structural analysis model. This model will be used for structural analysis of truss type of large structure such as agricultural farming facility.

• 한국공간구조학회논문집
• /
• 제5권3호
• /
• pp.117-122
• /
• 2005

This paper investigated the optimum design of truss structures based on Genetic Algorithms (GA's). With GA's characteristic of running side by side, the overall optimization and feasible operation, the optimum design model of truss structures was established. Elite models were used to assure that the best units of the previous generation had access to the evolution of current generation. Using of non-uniformity mutation brought the obvious mutation at earlier stage and stable mutation in the later stage; this benefited the convergence of units to the best result. In addition, to avoid GA's drawback of converging to local optimization easily, by the limit value of each variable was changed respectively and the genetic operation was performed two times, so the program could work more efficiently and obtained more precise results. Finally, by simulating evolution process of nature biology of a kind self-organize, self-organize, artificial intelligence, this paper established continuous structural optimization model for ten bars cantilever truss, and obtained satisfactory result of optimum design. This paper further explained that structural optimization is practicable with GA's, and provided the theoretic basis for the GA's optimum design of structural engineering.

• 한국강구조학회 논문집
• /
• 제24권5호
• /
• pp.549-558
• /
• 2012

본 연구에서는 유전 알고리즘(GA, Genetic Algorithm)을 이용하여 트러스 구조물에서 부재의 특성변화에 의한 손상탐지를 확인하였다. 구조물의 손상 탐지를 위하여 트러스 구조물을 모델링하여 특정 부재의 탄성계수를 감소시킴으로써 구조물의 손상을 결정하였다. 트러스 구조물의 해석은 특정 하중이 가하여졌을 경우의 정적 해석을 통하여 수행하였으며, 구조물의 손상 위치와 정도는 손상을 입기전의 구조물과 손상을 입은 구조물의 각 부재 변형률의 차이를 마이크로 유전 알고리즘을 통하여 비교 분석하여 탐지하였다. 본 연구에서는 트러스 구조물의 수치 해석 예제를 모델링하여 마이크로 유전 알고리즘을 이용하여 손상 탐지를 수행하였으며, 이를 통하여 구조물의 손상 위치와 정도가 탐지되는 것을 확인하였다.