Using nationally representative data from the 2008-2011 KNHANES, low pulmonary function was found to be associated with low muscle mass in community-dwelling older Korean adults.
Recently, a number of different structural health monitoring (SHM) techniques have been developed for the online inspection of air, land and sea engineering structures. Various smart materials are employed for detecting eminent damage in situ. Fatigue cracks in structural components are the most common cause of structural failure when exposed to fatigue loading. Fatigue design of structural components is typically accomplished either using a set of stress cycle (S‐N) data obtained from prior fatigue tests or using the fracture mechanics approach. The fracture mechanics approach considers the fatigue life of structures as a summation of crack initiation life and crack propagation life. The stress intensity factor (SIF) is required for the estimation of fatigue crack propagation life from the linear elastic fracture mechanics (LEFM) perspective. However, the accurate prediction of the SIF is difficult especially when the geometry or the boundary conditions of a structure becomes complex. In this study, a SHM application of macrofibre composite (MFC) sensors is presented. A set of MFC sensors is used for the real‐time measurement of the SIF. The measured values of the SIF are later used for the prediction of the crack propagation life. The impedance‐based SHM technique using the same set of MFC sensors is employed for the detection of crack initiation life.
The aim of the study was to investigate the dynamic failure initiation as well as the failure modes of insulation panels of liquefied natural gas (LNG) carriers. Insulation panels of LNG cargo tanks may include mechanical failures such as cracks as well as delaminations within the layers because of impact sloshing loads and fatigue loadings, and these failures cause a significant decrease of the structural safety. In this study, a structural health monitoring system was developed that employs fibre optic sensors for monitoring various failures that can occur in LNG insulation panels. Fibre optic sensors have the advantage of being embedded inside the insulation panels. The measurement signal of embedded fibre optic sensor is used to calculate the strain distribution within insulation panels and is analysed to identify the damage initiation. It has been observed that the presence of defects and delaminations produce noticeable changes in the strain measurement in a predictable manner. In addition, fibre optic sensors are used to measure static and dynamic strain variations with and without damage. It is expected that this study will be used as a fundamental study for the safety assessment of LNG insulation panels.
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