• International Journal of Concrete Structures and Materials
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• v.18 no.3E
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• pp.199-205
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• 2006

The composite frame system with reinforced concrete column and steel beam can be improved in its structural efficiency by complementing the shortcomings of the two systems. The system, however, has many inherent problems in practical design and construction process due to the dissimilarities of the materials. Considering these circumstance, this research aims for the development of a composite structural system which connects the steel beams to the R/C columns with higher structural safety and economy. Basically, the proposed connection system is composed of four split tees, structural angles reinforced by a stiffener, high strength steel rods, connecting plates and shear plates. Structural tests have been carried out to investigate the moment transfer mechanism 1Tom the beam flange to steel rods or connecting plates through the structural angle reinforced by a stiffener. The four prototype specimens have been tested until the flange of the beam reached a plastic state. The test results indicated that no distinct material dissimilarities between concrete and steel have been detected for the proposed hybrid beam-column connection system and that the stress transfer through the structural angle between the beam flange and steel rods or connecting plates was very encouraging.

• Composites Research
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• v.18 no.4
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• pp.59-65
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• 2005

This report is on the Reinforcing System(MFRI) for Concrete Structure using FRP ROD & High-Performance Mortar. The main characteristic of this system is as follow. First, the fiber rods in this system have seven times greater tensile strength than general reinforcing steel bars(re-bar) and the weight is a fifth lighter. Camels coated on the fiber rods' surfaces to improve adhesive strength and pull-out strength. Second, high strength shotcrete mortar is has very good workability and low rebound rate. After installing the Fiber Rods, Shotcrete mortar Is applied or sprayed to finish reinforcement. Finally, MFRI system has excellent fire-resisting performance and sogood tolerance against external environment by inserting fiber rods and reinforcing materials into mortar which has high compressive strength. It is applied to bridge slab, utility box and tunnel of civil engineering works, and beam and slab of building structures.

• Design & Manufacturing
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• v.7 no.1
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• pp.11-18
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• 2013

This paper presents the plastic inhomogeneous deformation behavior of bimetal composite rods during the axisymmetric and steady-state extrusion process through a conical die. The rigid-plastic FE model considering frictional contact problem was used to analyze the co-extrusion process with material combinations of Cu/Al. Different cases of initial geometry shape for composite material were simulated under different conditions of co-extrusion process, which includes the interference and frictional conditions. The main design parameters influencing on deformation pattern are diameter ratio of the composite components and semi-die angle. Efforts are focused on the deformation patterns, velocity gradient, predicted forming load and the end distance through the various simulations. Simulation results indicate that there is an obvious difference of forming pattern with various diameter ratio and semi-die angle. The analysis in this paper is concentrated on the evaluation of the design parameters on the deformation pattern of composite rod.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.313-318
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• 2002

The use of carbon fiber rods is a promising technology of increasing flexural and shear strength of deficient reinforced concrete members. The purpose of this experimental study is to investigate the fatigue behavior and strengthening effects of the strengthened bridge deck with isotropic and othortropic carbon fiber rod. This study shows a fatigue loading, compliance and S-N Curve between strengthened isotropically and othortropically. Then estimate the effective fatigue behavior of RC slab using composite rods that are inserted in high special purposed polymer mortar.

• Steel and Composite Structures
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• v.21 no.2
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• pp.357-371
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• 2016

Column base connections are critical components in steel structures because they transfer axial forces, shear forces and moments to the foundation. Exposed column bases are quite commonly used in low- to medium-rise buildings. To investigate shear transfer in exposed column base plates, four large scale specimens were subjected to a combination of axial load (compression or tension) and lateral shear deformations. The main parameters examined experimentally include the number of anchor rod, arrangement of anchor rod, type of lateral loading, and axial force ratio. It is observed that the shear resisting mechanism of exposed column base changed as the axial force changed. When the axial force is in compression, the resisting mechanism is rotation type, and the shear force will be resisted by friction force between base plate and mortar layer. The specimens could sustain inelastic deformation with minimal strength deterioration up to column rotation angle of 3%. The moment resistance and energy dissipation will be increased as the number of anchor rods increased. Moreover, moment resistance could be further increased if the anchor rods were arranged in details. When the axial force is in tension, the resisting mechanism is slip type, and the shear force will be resisted by the anchor rods. And the shear resistance was reduced significantly when the axial force was changed from compression to tension. The test results indicated that the current design approach could estimate the moment resistance within reasonable acceptance, but overestimate the shear resistance of exposed column base.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.26 no.2
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• pp.74-79
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• 2016

The lanthanum oxide nano-rods were grown on the surface of 3 mol% Yttria Partially Stabilized Zirconia ceramic composite which containing Lanthanum-Strontium Manganate, $La_xSr_yMn_zO_3$ for the purpose of endorsing the antistatic property. The diameter and the aspect ratio of the nano-rods were greatly changed according to the growing condition. With the optical microscope observation, the nano-rods shining brightly. It was confirmed that the major components of nano-rods is La, and Sr, Mn, Si are minor components by SEM and TEM analyses.

• Composites Research
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• v.25 no.5
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• pp.136-140
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• 2012

This paper describes the bone healing process of fractured long bones such as a tibia applied by composite IM rods using finite element analysis. To simulated tissue differentiation process mechano-regulation theory with a deviatoric strain was implemented and a user's subroutine programmed by a Python code for an iterative calculation was used. To broadly find the appropriate rod modulus for healing bone fractures, composite IM rods were analyzed considering the stacking sequence. To compare mechanical stimulation at fracture gap, two kinds of initial loading conditions were applied. As a result, it was found that the initial loading condition was the most sensitive factor for the healing performance. In case a composite IM rod made of a plain weave carbon fiber/epoxy (WSN3k) had a stacking sequence of $[{\pm}45]_{nT}$, the healing efficiency was the most effective under a initial load of 10%BW.

• Structural Engineering and Mechanics
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• v.24 no.3
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• pp.291-306
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• 2006

In order to improve the constructability and meanwhile ensure excellent seismic behavior, several innovative composite connection details were conceived and studied by the authors. This paper reports experimental results and observations on seismic behavior of steel beam bolted to reinforced concrete column connections (bolted RCS or BRCS). The proposed composite connection details involve post tensioning the end plates of the steel beams to the reinforced concrete or precast concrete columns using high-strength steel rods. A rational design procedure was proposed to assure a ductile behavior of the composite structure. Strut-and-tie model analysis indicates that a bolted composite connection has a favorable stress transfer mechanism. The excellent capacity and behavior were then validated through five full-scale beam to column connection model tests.

• International Journal of Concrete Structures and Materials
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• v.9 no.1
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• pp.61-67
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• 2015

The concept of horizontal shear connection utilization on wood-concrete beams intends to be an alternative connection detail for composite wood-concrete decks. The volume of sawn-wood is over three times more expensive than concrete, in Brazil. In order to be competitive in the Brazilian market we need a composite deck with the least amount of wood and a simple and inexpensive connection detail. This research project uses medium to high density tropical hardwoods managed from the Brazilian Amazon region and construction steel rods. The beams studied are composed of a bottom layer of staggered wood boards and a top layer of concrete. The wood members are laterally nailed together to form a wide beam, and horizontal rebar connectors are installed before the concrete layer is applied on top. Two sets of wood-concrete layered beams with horizontal rebar connectors (6 and 8) were tested in third-point loading flexural bending. The initial results reveal medium composite efficiency for the beams tested. An improvement on the previously conceived connection detail (set with six connectors) for the composite wood-concrete structural floor system was achieved by the set with eight connectors. The new layout of the horizontal rebar connectors added higher composite efficiency for the beams tested. Further analysis with advanced rigorous numerical Finite Element Modeling is suggested to optimize the connection parameters. Composite wood-concrete decks can attend a large demand for pedestrian bridges, as well as residential and commercial slabs in the Brazilian Amazon.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.437-440
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• 2000

Composite material consists of more than two materials and make various kinds of composite materials by combining different single materials. Copper clad aluminum composite material is composed of Al and Cu, and it has already been put to practical use in Europe because of its economic benefits. This paper presents the interface bonding according to the variation of extrusion ratio and semi-angle die by observing the interface between Cu and Al using metal microscope. By that result, we can predict the conditions of the interface bonding according to the extruding conditions.