본 연구는 수소 저장 용기의 지진 취약도 분석 시 요구되는 막대한 계산 자원 문제를 해결하고자, 기하학적 대칭성을 활용한 1/4 대칭 유한요소 모델(Quarter Model)을 개발하고 그 타당성을 검증하였다. 표준화된 AC 156 인공지진을 이용한 비선형 시간 이력 해석을 통해 Full Model과 응답을 비교한 결과, Quarter Model의 해석 시간을 Full Model의 20%를 가지고 해석을 완료하였으 며, 이에 따른 신뢰성 확보를 위해 최상단 변위를 통해 이를 검증하였을 때 0.13%의 미미한 오차를 보이며 변위 시간 이력 양상 역시 동일한 거동을 보이며 효율성 확보라는 연구 목표를 달성했다. 또한, 고유진동수, 강재와 콘크리트 주요부의 최대 응력에서 모두 높은 수준의 일치도를 보여 정량적 신뢰도를 입증하였다. 이를 통해 제안된 모델은 해석 정확도를 유지하면서 계산 비용을 획기적으로 절감 하는 효율적인 방법론임을 확인하였다. 다만 이는 균질 등방성 재료인 강재에 한정된 대칭 모델이며, 그 외의 재료 사용 시 추가적인 연구를 통한 모델 구축이 필요할 것으로 판단된다.

This study evaluates the structural stability of a hydrogen shut-off valve used in fuel cell electric vehicles (FCEVs) under extreme operating conditions, including high pressure and cryogenic temperatures. Using a one-way Fluid-Structure Interaction (FSI) analysis based on ANSYS CFX and Static Structural, the study simulates thermal and pressure loads on key components. The results show that the maximum equivalent stress occurs in the rod (361.22 MPa), while safety factors for all components remain above 2.11, confirming adequate structural integrity. In order to secure higher structural stability and reduce the weight of parts, attention should be paid to the selection of materials and improving the shape. The findings provide a valuable basis for improving the design reliability and optimization of hydrogen shut-off valves for future automotive applications. The leak tightness and durability tests of the hydrogen shut-off valve under cryogenic conditions verified its structural integrity, confirming its safety even after more than 5.2 million repeated operations.

This study establishes a transient CFD and coupled CFD-thermal analysis method for evaluating the insulation performance of a liquid hydrogen control valve system incorporating an MLI-VCS-MLI configuration. Parametric analysis was conducted by varying the thickness of MLI 2 (50–200 mm) to assess its impact on the temperature distribution and heat flux within the valve body and insulation layers. The results indicate that increasing the thickness of MLI 2 significantly reduces heat flux and improves insulation effectiveness, with the highest heat flux occurring at the outermost MLI layer exposed to ambient conditions. These findings provide valuable insights for optimizing insulation design in liquid hydrogen storage and transport systems, contributing to enhanced thermal management and energy efficiency.

This study evaluates how road profile and speed affect tire loads of a hydrogen tube trailer using MSC Adams/Car multibody dynamics simulation. A tractor and trailer loaded with 64 high-pressure cylinders were modeled, and four representative road profiles flat, pothole, short-wave, and long-wave were applied at 30, 60, and 80 km/h. Vertical tire load time histories were extracted for five wheel positions. Flat roads yielded stable loads matching static distribution. Potholes produced short, high-amplitude impacts (up to 120 kN at 30 km/h) with reduced peaks at higher speeds. Short-wave profiles caused severe asymmetric roll loads (67 kN at 80 km/h), while long-wave inputs generated smoother, moderate increases over longer durations. Load amplification diminished toward trailer axles due to suspension energy dissipation. The results inform structural design of tube trailers and development of speed-control or active load-mitigation strategies for autonomous hydrogen transport vehicles.

This study simulated the thermal characteristics of a liquefied hydrogen (LH) tank with varying multi-layer insulation (MLI) thickness and surrounding conditions. A transient heat conduction simulation was conducted using ANSYS Fluent software to predict the temperature distribution of the LH tank. The LH tank is composed of carbon fiber reinforced plastic (CFRP), MLI, and an Air layer for thermal insulation. A large MLI thickness delayed temperature changes inside the MLI due to its low thermal diffusivity. And then, the temperature rapidly increased near the outer wall, resulting in thermal non-uniformity. Therefore, when designing a LH tank with MLI materials, it would be necessary to optimize the design (i.e., MLI thickness) by considering structural stability issues caused by thermal non-uniformity. In addition, as the surrounding temperature increased and the convective heat transfer coefficient became higher, the enhanced heat transfer led to a higher temperature gradient within the LH tank, bringing the outer wall temperature of the LH tank closer to the environmental conditions. The results of this study will significantly contribute to establishing a comprehensive thermal database for predicting the thermal-structural behaviors, considering the thermal stress induced by the thermal distribution of LH tanks, which depends on the installation conditions and environment.

This study developed a coupled fluid-thermal analysis method for a liquid hydrogen control valve system. Using ANSYS CFX, a transient CFD analysis was performed for the control valve system, including MLI, and the thermal analysis was linked to evaluate the insulation performance of MLI. The analysis examined the pressure distribution, turbulent viscosity, and heat flux at the inlet and outlet, revealing that the highest heat flux occurred in MLI 2. This research is expected to contribute to improving the thermal shielding performance and efficient insulation design of liquid hydrogen storage systems.

Hydrogen has a wide flammability range and rapidly diffuses in air, making precision detection technology essential to prevent explosion risks and ensure system safety as the adoption of hydrogen infrastructure expands. Polymer materials are employed in such infrastructure to seal high-pressure hydrogen, and reliable measurement techniques capable of quantifying trace amounts of hydrogen permeating or leaking through these materials is necessary. In this study, a hydrogen quantification system combining volumetric analysis with image analysis was utilized to evaluate the hydrogen uptake and diffusivity of HDPE (high-density polyethylene), NBR (nitrile butadiene rubber), and EPDM (ethylene propylene diene monomer) under high-pressure conditions. The results indicated that HDPE and NBR samples containing silica filler exhibited hydrogen uptake behavior consistent with Henry’s law, while EPDM samples with carbon black filler demonstrated additional hydrogen adsorption on the carbon black surface. These research results provide a foundation for more precisely evaluating the permeation and leakage behavior of polymers in high-pressure hydrogen environments, and are expected to contribute to the safe and efficient development of hydrogen infrastructure.