• Computers and Concrete
• /
• v.31 no.3
• /
• pp.197-206
• /
• 2023

In this paper, the bending performance of a MSFRHPC (containing steel fiber, polyvinyl alcohol (PVA) fiber, and CW)-reinforced beam was studied for the first time. Introducing a multiscale fiber system increased the first crack load (up to 150%), yield load (up to 50%), and peak load (up to 15%) of reinforced beams. The multiscale fiber system delays cracking of the reinforced beam, reduces crack width of the reinforced beam in normal use, and improves the durability of the beam. Considering yield load and peak load, the reinforcing effect of multiscale fiber on the high-reinforcement ratio beam (1.00%) is better than that on the low-reinforcement ratio beam (0.57%). Introducing fibers slowed the development of cracks in the reinforced beam under bending. With the added hybrid fiber, the deformation concentration of reinforced beams after yield was more significant with concentration in 1 or 2 cracks. A model for predicting the flexural capacity of MSFRHPC-reinforced beams was proposed, considering the action of multiscale hybrid fibers. This research is helpful for structure application of MSFRHPC-containing CW.

• Nuclear Engineering and Technology
• /
• v.54 no.11
• /
• pp.4310-4321
• /
• 2022

The concept of dense granular-flow target (DGT) for the China Initiative Accelerator Driven Subcritical system (CiADS) is an attractive choice for high heat removal ability, low chemical toxicity, and radiotoxicity. A wobbling hollow beam is proposed to enhance the homogeneity of temperature rise of flowing particles in beam-target coupling zone. In this paper, the design procedure of target and beam parameters was discussed firstly. Then we simulated the heat deposition and transfer of the scanning beam in DGT to study the effect of beam parameters. The results show the flux density of proton beam plays a crucial role in the distribution of temperature rise while the contributions from scanning frequency heat transfer are also obvious. Moreover, heat transfer in transversal directions is insignificant, resulting in a low heat flux towards the sidewalls of DGT. This work not only contributes to the design of DGT, but also beneficial for understanding the beam-target coupling in porous materials.

• Journal of the Korea Concrete Institute
• /
• v.25 no.2
• /
• pp.233-240
• /
• 2013

In this study, experimental research was carried out to evaluate and improve the seismic performance of high strength R/C interior beam-column joints regions using advanced reinforcing detailings and high ductile fiber-reinforced mortar. Five specimens of retrofitted the beam-column joint regions using advanced reinforcing detailings and high ductile fiber-reinforced mortar were constructed and tested for their retrofitring performances. Specimens designed by retrofitting the interior beam-column joint regions (IJIR series) of existing reinforced concrete building showed a stable mode of failure and an increase in load-carrying capacity. Specimens of IJIR series, designed by the retrofitting of advanced reinforcing detailings and high ductile fiber-reinforced mortar in reinforecd beam-column joint regions increased its maximum load carrying capacity by 114.2~123.5% and its energy dissipation capacity by 1.55~1.85 times in comparison with the standard specimen of SIJC with a displacement ductility of 5.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2008.10a
• /
• pp.241-244
• /
• 2008

Automotive companies have conducted a study for light weigh body and crash safety. But It is difficult to adapt a mass production because of formability with high strength steel in the conventional stamping process. Recently, Automotive maker in the Europe, USA, Japan has applied a hot stamping with boron steel in the body structure. Hot stamping technology spread fast in various body parts of automobile. Bumper beam has been applied in the foreign automotive company so much nowadays. In this study, We will optimize crash performance of bumper beam using hot stamping through comparison with conventional bumper beam.

• Advances in concrete construction
• /
• v.2 no.1
• /
• pp.57-75
• /
• 2014

This paper presents an analysis of the results of an experimental program on the performance of a novel configuration of a hybrid FRP-concrete beam. The beam section consists of a GFRP pultruded profile, a CFRP laminate, and a concrete block all wrapped up using filament winding. It was found that the thickness of the concrete block and the confinement by the filament-wound wrapping had a profound effect on the energy dissipation behaviour of the beam. Using a shear punching model, and comparing the predicted results with the experimental ones, it was found that beyond a given value of the concrete block thickness, the deformational behaviour of the beam shifts from brittle to ductile. It was also found that the filament-wound wrap had many benefits such as providing a composite action between the concrete block and the GFRP box, improving the stiffness of the beam, and most importantly, enhancing the load carrying ability through induced confinement of the concrete.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.26 no.2
• /
• pp.267-274
• /
• 2002

Using a flexible rotating beam test bed, experimental verification of a flexible multibody dynamic simulations for a rotating beam model has been carried out. The test bed consists of a flexible arm, harmonic driver reducer, AC servo motor and DSP board with PC. The mechanical ports of the test bed has been designed using 3D CAD program. For the simulation model, mass and moment of inertia of each part of the flexible rotating beam test bed are also obtained from 3D CAD model. In the flexible multibody dynamic simulations, the substructuring model has been established to capture nonlinear effects of the flexible rotating beam. Through the experimental verification, substructuring model provides better results than those from the linear model in the high speed rotation.

• Journal of the Optical Society of Korea
• /
• v.14 no.2
• /
• pp.127-130
• /
• 2010

We have developed an efficient electron beam (e-beam) source, a microcolumn, that can be used as a source module for of microscopy and its applications. To obtain a low operating voltage, a very sharp cold field electron emitter was developed by electrochemically etching a tungsten wire. Laser diffraction was used for the fabrication of high-quality electron lenses and for their precise alignment. The measurement of the e-beam currents, and SEM images captured by the microcolumn confirmed the potential of the device as a very good e-beam source.

• Proceedings of the IEEK Conference
• /
• 2003.07a
• /
• pp.274-277
• /
• 2003

Millimeter-wave networking is composed of narrow beam link. High directivity of the beam provides either advantage or disadvantage in comparison with conventional wide-lobe microwave communications. In such networks, it is very substantial that beam connecting point to point is fixed in right direction. It is major requirement in the beam network to keep the beam in best direction. In this paper, We propose the method to find a best suited direction of the antenna's beam using the Genetic Algorithm in point-to-point link. Proposed method presume that each station knows his direction $\theta$$_1$,$\theta$$_2$ at every step of Genetic Algorithm, then it can be expected that GA is possible to search the ideal solution. Intensity of the received signal is evaluated by the multiplication of lengths to the point which the lobe meets with the horizontal line.

• Structural Engineering and Mechanics
• /
• v.72 no.6
• /
• pp.797-807
• /
• 2019

In this study, an exact transfer matrix expression for a twisted uniform beam considering the effect of shear deformation and rotary inertia is developed. The particular transfer matrix is derived by applying the distributed mass and transcendental function while using a local coordinate system. The results obtained from this method are independent for a number of subdivided elements, and this method can determine the required number of exact solutions for the free vibration characteristics of a twisted uniform Timoshenko beam using a single element. In addition, it can be used as a useful numerical method for the computation of high-order natural frequencies. To validate the accuracy of the proposed method, 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 shear deformation and rotary inertia for a twisted beam.

• Transactions on Electrical and Electronic Materials
• /
• v.7 no.6
• /
• pp.305-308
• /
• 2006

We have studied liquid crystal (LC) aligning capabilities for homeotropic alignment and the control of tilt angles on the $SiO_{x}$ thin film by electron beam evaporation method. A high tilt angle of about $86.5^{\circ}$ was obtained, and also the suitable tilt angle of the NLC on the $SiO_{x}$ thin film at $20{\sim}50\;nm$ thickness with e-beam evaporation can be achieved. The uniform LC alignment on the $SiO_{x}$ thin film surfaces with electron beam evaporation can be achieved. It is considerated that the LC alignment on the $SiO_{x}$ thin film by electron beam evaporation is attributed to elastic interaction between LC molecules and micro-grooves at the $SiO_{x}$ thin film surface created by evaporation.