본 연구는 다중벽 탄소나노튜브(MWCNT)로 보강된 복합재 구조의 동적 해석을 다루었다. Mori-Tanaka 모델을 기반으 로 MWCNT 중량 비율, 패널의 곡률, 그리고 CNT의 임의 배열이 복합재의 동적거동에 미치는 상호작용을 연구하였다. 본 연구 결과는 CNT의 부피함유비율의 변화에 따른 복합재의 유효탄성계수를 예측하는 기존 문헌결과와 비교하여 검증하였다. 수치해 석 예제는 복합재의 동적 특성을 평가함에 있어서 MWCNT 보강의 불규칙한 배열 또는 기울어진 방향으로 배치된 효과에 대한 중요성을 제시하였다.

Polypyrrole (PPy) decorated on reduced graphene oxide (rGO) films is successfully prepared with pyrrole (Py) monomers and rGO through one-step combining oxidation with polymerization reaction. Compared with the pure individual components, rGO/PPy compound turns out better electrochemical characteristics owing to the introduction of rGO sheets, which improves the specific surface area and the conductivity of composite material. When the amount of rGO is 10% of the total, the rGO/PPy compound delivers the best capacitance of 389.3 F g−1 at 1.0 A g−1 in a three-electrode system and 266.8 F g−1 at 0.25 A g−1 in the symmetric supercapacitor system. In addition, asymmetric device (rGO/PPy//AC) has been successfully fabricated using optimized rGO/PPy compound as positive electrode, activated carbon as negative electrode (AC) and 1 M Na2SO4 aqueous solution as electrolyte. The device obtains long cycle stability under the high-voltage region from 0 to 1.6 V, meanwhile displaying the satisfied energy density of 19.7 Wh kg−1 at 478.1 W kg−1. Besides, the rGO/PPy//AC device presents satisfactory rate capability and long life time.

신재생 에너지의 확대를 위한 대용량 에너지 저장장치로서 레독스 흐름전지 기술의 중요성이 부각되고 있다. 레독스 흐름전지는 양극 및 음극 전해액을 셀에 순환시켜 전해액에 용해되어 있는 활물질의 산화 및 환원 반응을 유도시키는 전지로서 전지의 효율 및 수명 확보를 위해서 양쪽 전해액을 분리시켜 주며 이온전달을 일으킬 수 있는 멤브레인의 사용이 필수적이다. 그러나 기존 레독스 흐름전지에 사용되는 멤브레인은 활물질 차단 특성, 이온 전달 특성, 물리화학적 내구성 및 가격 측면에서 부족한 특성이 많으며, 이를 개선함으로서 레독스 흐름전지의 효율, 수명 향상 및 가격저감 효과를 얻을 수 있다. 본 연구에서는 이러한 레독스 흐름전지용 멤브레인의 문제점을 정리하고, 이를 개선시키기 위한 멤브레인 소재 및 구조설계 전략에 대해 논의한다. 특히 활물질 차단과 내구성 향상 혹은 가격저감을 동시에 만족시키는 복합막 기술을 소개한다.

In this paper, the result of application of this simple method of vibration analysis developed by the author, to the special orthotropic plates with variable cross-section, and with a pair of opposite edges simple supported and the other pair of opposite edges free is presented. This problem represents the simple-supported single span bridge system without effective longitudinal edge beams. The effect of concentrated point mass/masses is also studied.

We carried out a dynamic instability assessment of carbon nanotube reinforced composite (CNTRC) and carbon nanotubes/fiber/polymer composite (CNTFPC) skew plates based on the high-order shear deformation plate theory (HSDT). The multiscale interactions between carbon nanotube (CNT) ratios and skew angles on the dynamic instability for various length-thickness ratios are studied using a two-dimensional finite element model developed for this study. The results were verified by those reported in the literature show the interactions between the CNT reinforcement and skew angles in the skew laminate. Numerical examples show the importance of CNT reinforcement when assessing the dynamic instability of CNTRC and CNTFPC skew plates.

FO is prominent membrane technology for desalination due to no hydraulic pressure requirement and low fouling propensity compared to RO. TFC membrane was widely used due to excellent perm-selectivity and chemical resistance. TFC membrane consists of dense and support layer. Academic efforts focused on advance TFC membranes characteristics and performances. This work attempts to fabricate TFC FO membrane with highly permeable ultra-thin intermediate layer on the support layer using polydopamine and graphene oxide. Role of the intermediate layer on performances was demonstrated via characterization and FO operation.

In this paper, the method of vibration analysis for calculating the natural frequency is presented. This method is a simple but exact method of calculating natural frequencies corresponding to the modes of vibration for the cantilevered composite materials conical beam. The influence of natural frequency of the cantilevered composite materials conical beam is presented. This method may be extended to stability analysis of complex structureal elements.

This study investigates the trend on application technologies of advanced composite materials and outlook on research development to the challenges associated with innovative applications of advanced composite materials in construction: 1) initiation of new construction materials; 2) development of rehabilitation techniques for aging infrastructural systems; 3) implementation of greener construction approaches; and 4) introduction of multifunctional advanced composite materials. This fundamental investigation will assure wide field implementation of advanced composite materials in construction.

Nowadays, advanced composite material are widely used in civil & architectural structures. Analysis of foam core sandwich bridges for simple supported made by advanced composite materials is presented in this paper. For the design of advanced composite materials bridge, foam core shape is economical and profitable. Navier’s solutions are compared in this paper to verify the authenticity of Finite Difference Method. Finite Difference Method is used for analysis of the pertinent problems. In this study, reduction rate of tensile strength for E-glass fibers due to increase in size, strength reduction ratios of according to mass, stress changes according to form core height and safety ratio due to increase form core height is presented. Tasi-Wu failure strength theory are used. Strength reduction is necessary for safe design of a structures.

The purpose of this paper is to demonstrate to the practicing engineers, how to apply the advanced composite materials theory to the slab bridges. For general construction material used, there is certain theoretical limit in sizes. For super slab bridges construction, the reduction in panel weight is the first step to take in order to break such size limits. For a typical slab bridges panel, both concrete and advanced composite sandwich panels are considered. The concrete panel is treated as a special orthotropic plate. Advanced composite sandwich panels are considered as a self-weights less than one tenth of that of concrete panel, with deflections less than that of the concrete panel. This conclusion gives good guide line for design of the light weight of slab bridges.

Compared with conventional construction materials such as steel and concrete, the advanced composite materials are corrosion-free, light-weight, and when used as construction materials, the construction period can be made less than one-tenth needed for conventional materials. However, because of the difficult theories and formulas, the ordinary construction engineers have difficulties in understanding and calculating formulas needed in construction. In this paper, calculation of the stiffnesses of the advanced composite laminated plates and compared with the result of stiffnesses.

In this paper. the effects of the aspect ratio on the natural frequency of the advanced composite road structures is studied. The advanced composite structures are too difficult for such design engineers for construction and some simple but accurate enough methods are necessary. Some laminate orientations have decreasing values of  ,  ,  and  stiffnesses as the ply number increases. The plate aspect ratio considered is from 1 to 5. Most of the road structures have large aspect ratios, for such cases further simplification is possible by neglecting the effect of the longitudinal moment terms.

PURPOSES: The purpose of this paper is to demonstrate to the practicing engineers, how to apply the advanced composite materials theory to the road structures. For general construction material used, there is certain theoretical limit in sizes. For super road structure construction, the reduction in panel weight is the first step to take in order to break such size limits. METHODS: For a typical road structures panel, both concrete and advanced composite sandwich panels are considered. The concrete panel is treated as a special orthotropic plate. RESULTS: All types of advanced composite sandwich panels are considered as a self-weights less than one tenth of that of concrete panel. The concrete panel is treated as a special orthotropic plate to obtain more accurate result. CONCLUSIONS: Advanced composite sandwich panels are considered as a self-weights less than one tenth (10%) of that of concrete panel, with deflections less than that of the concrete panel. This conclusion gives good guide line for design of the light weight of road structures.

PURPOSES: This paper aims to give a guideline and the way to apply the advanced composite materials theory to the road structures with different cross sections to the practicing engineers. METHODS: To simple but exact method of calculating natural frequencies corresponding to the modes of vibration of road structures with different cross sections and arbitrary boundary conditions. The effect of the D22 stiffness on the natural frequency is rigorously investigated. RESULTS: Simple method of vibration analysis for calculating the natural frequency of the different cross sections is presented. CONCLUSIONS: Simple method of vibration analysis for calculating the natural frequency of the different cross sections is presented. This method is a simple but exact method of calculating natural frequencies of the road structures with different cross sections. This method is extended to be applied to two dimensional problems including composite laminated road structures.

PURPOSES: Current theories for composite structures are too difficult for design engineers for construction. The purpose of this paper is to demonstrate to the practicing engineers, how to apply the advanced composite materials theory to the road structures. METHODS: Some laminate orientations have decreasing values of D16, B16, D26 and B26 stiffnesses as the ply number increases. The plate aspect ratio considered is from 1 to 5. In order to study the effect of Mx on the equilibrium equations, two cases are considered. Mx term is considered or neglected. RESULTS: Most of the road structures have high aspect ratios, for such cases further simplification is possible by neglecting the effect of the longitudinal moment terms. CONCLUSIONS: Most of the road structures have plate aspect ratios higher than 2. It is concluded that, for all boundary conditions, neglecting the longitudinal moment(Mx) terms is acceptable if the aspect ratio (a/b) is equal to or higher than 2. This conclusion gives good guide line for design of the road structures.