본 연구는 3차원 비선형 유한요소해석을 이용하여 고속도로 2주형 교각 코핑부에서 철근을 유리섬유보강폴리머(GFRP) 보강 근으로 대체하는 경우를 평가하였다. 콘크리트의 균열, 손상 및 보강근 응답을 모사하기 위해 콘크리트 손상소성(CDP) 모델을 적용하 였다. 단조하중 조건에서 철근 기준 Case와 다수의 GFRP Case를 비교하였다. 주요 변수로는 GFRP의 강성, 콘크리트와의 부착계수 영향, 그리고 수직 전단보강근 상세 배근을 포함하였다. 수치해석 모델은 실험 경향과의 비교를 통해 검증되었으며 전반적인 거동이 일관되게 나타났다. GFRP로의 대체는 철근 대비 강성과 하중 전달 메커니즘을 변화시켰다. 또한 콘크리트 손상이 전체 응답과 파괴 진행을 지배하는 주요 요인으로 나타났다. GFRP 강성이 높고 부착성능이 우수할수록 구조 효율과 상세설계의 실현성이 향상되었다. 적절한 설계가 전제될 경우 전단보강근의 양은 전체 거동에 미치는 영향이 제한적인 범위에서 최적화가 가능하였다. 이상의 결과는 GFRP 적용의 실무적 가능성을 뒷받침하는 동시에, GFRP의 선형탄성ㆍ취성 거동과 국부 응력집중 가능성을 고려할 필요가 있음을 시사한다.
This study investigates the repeated impact behavior and compression-after-impact (CAI) performance of triaxially braided carbon/glass fiber-reinforced polymer (C/GFRP) composite tubes. A two-stage experimental strategy was proposed to evaluate the synergistic effect of interlayer hybridization and axial yarn reinforcement on damage evolution and mechanical performance. In Stage I, six hybrid braided tubes with different carbon/glass stacking configurations—including pure carbon, pure glass, layered, and reversed-layered structures—were subjected to repeated low-velocity impacts at 31 J. Micro-CT was employed to reconstruct the internal damage morphology and assess damage accumulation. The optimal interlayer configuration was selected based on impact force, displacement, energy absorption, and internal failure characteristics. In Stage II, the selected structure was further reinforced with four types of axial yarns (none, carbon, glass, and carbon/glass alternating), and their axial compressive and CAI performance after 10 J impact was tested. Results revealed that reversed interlayer design effectively suppressed crack propagation and improved damage tolerance under cyclic impacts. Moreover, the inclusion of hybrid axial yarns significantly enhanced residual compressive strength without compromising energy absorption. This study establishes a lightweight, high-performance braided tube design strategy suitable for aerospace and transportation applications.
In this study, foamed glass was fabricated by adjusting the final heat treatment temperature. The heat treatment temperatures ranged from 900 °C to 1,100 °C at 50 °C intervals. Blast furnace slag (BFS) powder was mixed with foaming agent such as CaCO3, Ca3(PO4)2, Na2SiO3 and NaOH, pressed under compression, then heat treated to form a porous and stable glass structure. Their optical, thermal, and physical properties, including thermal coefficient, density, glass transition temperature (Tg) and X-ray diffraction patterns, were investigated. As the heat treatment temperature increased, the apparent density decreased from 1.44 g/cm3 to 1.03 g/cm3 while the porosity increased from 46.03 % to 58.89 %. Thermal coefficient decreased from 9.997 × 10-6 /K to 9.417 × 10-6 /K. The main XRD peak gradually shifted toward a lower angle, indicating an expansion of the glass network structure. Results showed that foamed glass based on BFS, developed with a porous structure, can be used as an effective thermal insulation material, suggesting the potential for the commercial utilization of slag.
CNT/epoxy composite film (CECF) was prepared and used to fabricate the interlayer stiffened and reinforced photothermal synergistic curing glass fiber-reinforced polymer (GFRP) composites, and the influence of the photothermal effects of CECF on compressive strength and failure mechanism of the composite was investigated. Compared to GFRP composite, the uniform and wide temperature distribution in the in-plane and thickness direction was exhibited due to the heat from the lattice vibrations induced by photothermal conversions of CECF, thereby facilitating the decomposition of the thermal initiator and the increase of the curing degree in the CECF/GFRP composite. The in-plane shear modulus and interlaminar shear strength (ILSS) of the CECF/GFRP composite were 12.2% and 13.7% higher than those of the GFRP composite, respectively, indicating the enhanced deformation resistance and interfacial adhesion of the interlayer region. The compressive strength of the CECF/GFRP composite was increased by 14.1% relative to the GFRP composite, which was ascribed to restricted kink-band and delayed delamination damage during the compression process of composite.
This study investigates the vitrification of blast furnace slag (BFS) by adjusting the content of steel slag and the added amount of E-glass. SaEb glasses were prepared with a composition of x wt% BFS and (100-x) wt% E-glass (x = 10, 20, 30, 40, and 50). Each composition was melted in a platinum crucible under atmospheric conditions at 1,500 °C for 2 h, and transparent glasses with a transmittance exceeding 75 % were fabricated. All SaEb glasses exhibit an amorphous pattern, indicating successful vitrification. We also analyzed their optical, thermal, and physical properties, including Fourier transform infrared spectroscopy (FT-IR), glass transition temperature (Tg), and x-ray pattern. As the E-glass content increased, the glass transition temperature of blast furnace slag-based glass decreased from 765 °C to 734 °C due to the weakening of the SiO4 unit structure. In all compositions, the glass transition–crystallization temperature difference exceeded 220 °C, confirming the glasses stability for slag fiber applications. The blast furnace slag-based glass exhibits potential for application in slag fiber production, and is expected to provide fundamental data for future studies on related materials.
The plausibility factors influencing heterogeneous nucleation at the metal/glass interface were systematically investigated as a function of temperature. Secondary phase formation at the metal/glass interface is governed by the contact angle, which is affected by volumetric changes, microstructural evolution driven by metal ion diffusion, and redox reactions influenced by the arrangement of oxygen layers on the metal surface. A comprehensive model was developed to describe these plausibility factors based on observed interfacial phenomena. Despite the inherent non-uniformity in ion distribution within the glass, the interfacial diffusion coefficient, derived from an Arrhenius plot, exhibited a clear temperature dependence, reflecting thermally activated diffusion processes. Above the glass transition temperature (Tg), chemical interactions between diffusing metal ions and migrating glass constituents were identified as the main driving force for secondary phase formation at the metal/glass interface. These chemical reactions not only alter the local stoichiometry but also contribute to structural rearrangements at the interface. The results highlight the complex interplay between the thermal, chemical, and structural factors that control nucleation at the metal/glass boundary. The proposed model provides valuable insight into the mechanisms of interfacial phase formation and offers a useful framework for the design and processing of metal/glass composite systems with tailored properties.
본 연구에서는 온대산재 및 남양재 원목을 표층재로하고, 금속, 유리섬유, 탄소섬유로 보강한 코르크 보드를 중층에 배열한 코르크 복합 원목마루판 의 치수안정성을 평가하였다. 표층재에 따른 코르크 복합 원목마루판의 평균 흡수율은 백합나무(Tu)가 6.1%로 가장 높은 값을 나타내었고, 티크와 멀바우가 4.7%로 가장 낮은 값을 나타내었으며, 밀도가 낮은 온대산재를 배열한 원목마루판보다 남양재에서 낮은 값을 나타내는 것이 확인되었다. 중층보강재는 CM (cork board-metal) 타입이 CG (cork board-glass fiber) 및 CC (cork board-carbon fiber)타입에 비하여 높은 흡수율을 나타내어 밀도에 따른 흡수량의 차이가 확인되었다. 표층 수종에 따른 흡수두께팽창률은 백합나무가 7.2%로 가장 높은 값을, 티크(T)가 3.9%로 가장 낮은 값을 나타내었다. 전반적으로 금속 보강 원목마루판(CM)의 흡수두께팽창률은 유리섬유(CG)와 탄소섬유(CC)에 비하여 금속이 2–3배 높은 값을 나타내었다. 금속 보강 원목마루판을 제외한 모든 원목마루판은 목질 마루판에 관한 KS 규격 기준을 충족하는 우수한 치수안정성을 나타내는 것이 확인되었다.
This study proposes strategies for projecting media art onto glass-surfaced architecture, addressing challenges such as transparency, reflection, and visibility. Using the Aqua Art Overpass in Seoul as a case study, the research compares glass and opaque surfaces through mock-ups and luminance simulations. By applying high-lumen projectors, special films, and content adjustments, the study demonstrates that glass facades can effectively serve as dynamic media surfaces. The findings highlight the visual and spatial potential of glass in urban environments, offering practical insights for future applications in architectural media art.
국내 기후변화와 급격한 도시화가 진행함으로써 도심지 불투수 면적 증가로 인하여 자연적인 물순환이 원활히 이루어 지지 않고 있다. 이로 인해 국지성 폭우로 인한 지표수의 증가로 도심지 홍수 피해가 빈번하게 발생하고 있는 실정이다. 이에 본연구에서는 주차장 매립 빗물저류조를 통하여 지표 유출량을 감소시켜 원활한 물순환에 기여하고 그에 따른 해 당 구조물의 상부 하중과 배열 방식에 따른 거동 특성을 분석하고자 한다. 해당 구조물의 분석은 유한요소 해석을 이용 하였으며, 분석 결과 매립 깊이 3m 이상 시 상부 하중이 저류조에 적용되는 하중이 급격하게 저감되는 결과를 나타냈다.
국내 태양광 산업은 2000년대 초 크게 성장하였으나 태양광 패널의 수명이 도래함에 따라 폐패널 발생량이 급격히 증 가할 것으로 예상된다. 그러나 태양광 패널의 주요 구성요소인 강화유리는 상용화된 재활용 기술이 부족하여 대부분 파 쇄 후 매립되고 있는 실정이다. 향후 대량 발생하게 될 폐패널의 재활용 기술 개발 필요성이 대두됨에 따라 태양광 폐패 널의 강화유리를 아스팔트 콘크리트 재료로서 재활용할 수 있는 기술을 개발하고자 하였다. 따라서 폐패널 유리 골재를 제조 및 이를 적용한 아스팔트 혼합물의 배합설계를 수행하였으며 일반 아스팔트 혼합물과 폐패널 유리 골재 아스팔트 혼합물의 성능평가 및 경제성을 비교·분석하였다. 그 결과 폐패널 유리 아스팔트 혼합물이 저온균열 저항성을 제외한 모 든 성능 시험에서 우수한 성과를 보였으며, 경제성 또한 일반 아스팔트 혼합물과 비교 시 뛰어난 것으로 나타났다.
Semiconductors, optimized for artificial intelligence (AI) applications, are efficiently handling large-scale data processing and complex computations with high speed and low power consumption. They accelerate AI model training and inference in data centers, cloud services, autonomous vehicles, and mobile devices. As demand for high-speed data transmission and extensive data processing grows, global companies are developing proprietary AI semiconductors, and subsequently, high-density packaging technologies are needed to interconnect multiple processor chips. To achieve this, an interposer is required. An interposer is a layer used in packaging technology for combining multiple chips, which includes wiring that is inserted to electrically connect a semiconductor chip with a substrate that has a significant pitch difference. Among the materials employed as substrates or interposers, organic, silicon and glass are being considered. While silicon interposers are usually used to connect the main substrate and multiple chips, producing very thin silicon wafers and controlling warpage is challenging, and so they suffer from poor yield and integration. Also, organic substrates have difficulty achieving fine pitch because of their uneven surface and warpage. On the other hand, glass substrates and interposers have good electrical and thermal properties. For this reason, this study investigated AI semiconductor packaging trends and through glass via (TGV) technology, emphasizing the importance of suitable glass material selection, reliable glass-metal bonding and application to solder bumping on TGV. Advances in AI and TGV technologies are expected to drive next-generation AI semiconductor packaging development.
AR (alkali resistant)-glass fibers were developed to provide better alkali resistance, but there is currently no research on AR-glass fiber manufacturing. In this study, we fabricated glass fiber from AR-glass using a continuous spinning process with 40 wt% refused coal ore. To confirm the melting properties of the marble glass, raw material was put into a (platinum) Pt crucible and melted at temperatures up to 1,650 °C for 2 h and then annealed. To confirm the transparent clear marble glass, visible transmittance was measured and the fiber spinning condition was investigated by high temperature viscosity measurement. A change in diameter was observed according to winding speed in the range of 100 to 700 rpm. We also checked the change in diameter as a function of fiberizing temperature in the range of 1,240 to 1,340 °C. As winding speed increased at constant temperature, fiber diameter tended to decrease. However, at fiberizing temperature at constant winding speed, fiber diameter tended to increase. The properties of the prepared spinning fibers were confirmed by optical microscope, tensile strength, modulus and alkali-resistance tests.
The semiconductor and display industries require the development of plasma resistant materials for use in high density plasma etching process equipment. Yttria (Y2O3) is a ceramic material mainly used to ensure good plasma resistance properties, which requires a dense microstructure. In commercial production, a sintering process is applied to reduce the sintering temperature of Y2O3. In this study, the effect of the addition of glass frit to the sintered specimen was examined when manufacturing yttria sintered specimens for semiconductor process equipment parts. The Y2O3 specimen was shaped into a Ø50 mm size and then sintered at 1,600 °C for 1~8 h. The characteristics, X-ray diffraction pattern, densities, contraction rate of the specimen, and swelling of the surface of the Y2O3 specimens were investigated as a function of the sintering time and glass frit addition. The Y2O3 specimen exhibited a density of over 4.9 g/cm3 as the sintering time increased, and the swelling phenomenon characteristics were improved by glass frit, by controlling particle size.
본 연구는 탄소 기반 필러인 탄소나노튜브 (Carbon nanotube, CNT), 탄소 섬유 (Carbon fiber, CF) 와 중공유리구체 (Hollow glass microsphere, HGM)를 혼입한 전도성 복합재료가 다양한 열화 상황 에 노출된 이후의 발열성능을 조사하고 분석하였다. 대부분 상황에서 시멘트 기반의 재료들은 질산 및 황산의 침투 또는 동결융해와 같은 다양한 자연적 열화상황에 노출되게 된다. 본 연구는 기존의 이러 한 한계를 극복하고자 HGM, 전도성 필러를 혼입한 전도성 복합재료를 제조하였고, 물리적·전기적 및 열적 특성을 조사하였다. 모든 시편에서 HGM의 혼입은 시편의 밀도와 열 전도도를 감소시켰으며, 다 량의 혼입은 강도와 전기 전도도를 감소시키는 결과를 관찰할 수 있었다. 그러나 적정량의 혼입은 오 히려 전기 전도도를 향상시키는 결과를 확인할 수 있었으며, 반복적인 발열 실험에서의 성능 유지 또 한 미혼입 시편에 비하여 상대적으로 뛰어난 것을 관찰할 수 있었다. 이러한 HGM의 혼입에 대한 영 향을 더욱 자세하게 분석하기 위하여 수은압입법, 주사전자현미경, 제타전위 및 라만분광법 등의 분석 이 수행되었다.