• Wind and Structures
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• 제7권6호
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• pp.393-404
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• 2004

The design of truss type sign support structures is based on the guidelines provided by the American Association of State Highway and Transportation Officials Standard Specifications for Highway Signs, Luminaries and Traffic Signals and the American Institute of Steel Construction Design Specifications. Using these specifications, the column design strength is normally determined using the effective length approach. This approach does not always accurately address all issues associated with frame stability, including the actual end conditions of the individual members, variations of the loads in the members, and the resulting sidesway buckling for truss type sign support structures. This paper provides insight into the problems with the simplified design approach for determining the effective lengths and discusses different approaches for overcoming these simplifications. A system buckling approach, also known as a rational buckling analysis, is used in this study to determine improved predictions for design strength of truss type sign support structures.

• Advances in Computational Design
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• 제1권2호
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• pp.119-138
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• 2016

In this article, hybridization of enhanced colliding bodies optimization (ECBO) with upper bound strategy (UBS) that is called UECBO is proposed for optimum design of truss structures with frequency constraints. The distinct feature of the proposed algorithm is that it requires less computational time while preserving the good accuracy of the ECBO. Four truss structures with frequency limitations selected from the literature are studied to verify the viability of the algorithm. This type of problems is highly non-linear and non-convex. The numerical results show the successful performance of the UECBO algorithm in comparison to the CBO, ECBO and some other metaheuristic optimization methods.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.916-921
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• 2004

At present, the highest operation speed of general domestic train is in the level of 140km/h and it is being improved to reach at the level of 200km/h in 2011. The improved environment of train operation speed which inevitably occurs owing to the operation of KTX on the existing line badly requires technology development such as testing and evaluating technology of factors hindering high speed of railway infrastructure including railway bridge, technology to ensure operation safety and technology to evaluate structure stability. Comparing dynamic numerical interpretation for railway truss bridge and load of design standard by using dynamic response measurement and analysis for the railway truss bridge currently in use, this study established the improvement program to ensure the lateral dynamic safety of truss bridge with the increased speed of train.

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

• 한국공간구조학회논문집
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• 제4권1호
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• pp.39-48
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• 2004

Generally, a structural system with large inextensional deformations, or in other words, non-strained deformation is called as 'Unstable Structure', Truss-linked structures, cable structures, membrane structures and movable structures as foldable space structures etc, are included in this category. In this paper, a dynamic analysis method for unstable structural systems is presented. Governing equations for dynamic analysis of unstable truss structures with inextensional displacements are derived. Because of singularity of inverse matrixin in practical analysis of unstable structure, the generalized inverse matrix is Introduced to resolve the singular problem. Also, the RREF technique is used to get the inextensional displacement mode. Two unstable truss structures are analyzed by using presented method. Damping is not considered. From the given results, it is known that proposed method is useful to figure out the dynamic behavior of unstable truss structures.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1997년도 봄 학술발표회 논문집
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• pp.152-159
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• 1997

This unit - structure of truss stabilized by cable tension is composed of four truss member adding to a central post and eight cables, and is connected by hinge joints and is stabilized by cable tension. As this unit - structures itself is a statically closed and stabilize system individually, it can be employed to assemble a structure with a variety of configuration. In this paper, for determination the shape of the unit - structure of truss stabilized by the cable, characteristics such as the stabilized range of the various geometrical parameter about unit system and the relation of the best governing paramter is demonstrated, and the relation of the results is compared in the range for the stabilization of unit-structure.

• Structural Engineering and Mechanics
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• 제11권4호
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• pp.393-406
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• 2001

The present paper discusses the behavior of the reinforced concrete beams subjected to torsion by applying the endochronic plastic model in conjunction with the softened truss model. The endochronic constitutive equations are developed to describe the behavior of concrete. The mechanical behavior of concrete is decomposed into hydrostatic part and deviatoric part. New definition of the bulk modulus and the shear modulus are defined in terms of compressive strength of concrete. Also, new deviatoric hardening function is developed. Then, the endochronic constitutive equations of concrete are applied with the softened truss model for the behavior of the reinforced concrete beams subjected to torsion. The theoretical results obtained based on the present model are compared with the experimental data. The present model has shown the ability to describe the behavior of reinforced concrete beams subjected to torsion.

• Structural Engineering and Mechanics
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• 제55권4호
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• pp.801-813
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• 2015

Flexural stiffness of bridge spans has become even more important parameter since Eurocode 1 introduced for railway bridges the serviceability limit state of resonance. For simply supported bridge spans it relies, in general, on accurate assessment of span moment of inertia that governs span flexural stiffness. The paper presents three methods of estimation of the equivalent moment of inertia for such spans: experimental, analytical and numerical. Test loading of the twin truss bridge spans and test results are presented. Recorded displacements and the method of least squares are used to find an "experimental" moment of inertia. Then it is computed according to the analytical method that accounts for joint action of truss girders and composite deck as well as limited span shear stiffness provided by diagonal bracing. Finally a 3D model of finite element method is created to assess the moment of inertia. Discussion of results is given. The comparative analysis proves efficiency of the analytical method.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.325-328
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• 2006

Joint structures of composite truss bridges can have the same details for the connection between diagonal members and upper concrete slab as the connection between diagonal members and lower concrete slab. Adequate connection details should be decided according to design codes, constructibility, and economical evaluation. It is necessary to clarify the design check items and load transferring mechanism because combined external loads on composite truss bridges are concentrated at the joints. Joints with gusset plates and stud connectors are applied and complicated joint details may arise some problems in construction. This paper deals with experimental evaluation of the joints in composite truss bridges and proper design provisions were investigated to enhance the details. Push-out test specimens with group studs were fabricated and the effects of grouping and bent studs were studied.

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