Examinando por Materia "Damage detection"

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    Consumed fatigue life assessment of composite material structures by optical surface roughness inspection
    (Trans Tech Publications Ltd., 2013-01-01) Zuluaga, P.; Frövel, M.; Restrepo, R.; Trallero, R.; Atienza, R.; Pintado, J.M.; Belenguer, T.; Salazar, F.; Universidad EAFIT. Departamento de Ciencias Básicas; Óptica Aplicada
    A strong knowledge of the fatigue state of highly advanced carbon fiber reinforced polymer composite (CFRP) structures is essential to predict the residual life and optimize intervals of structural inspection, repairs, and/or replacements. Current techniques are based mostly on measurement of structural loads throughout the service life by electric strain gauge sensors. These sensors are affected by extreme environmental conditions and by fatigue loads in such a way that the sensors and their systems require exhaustive maintenance throughout system life. This work is focused on providing a new technique to evaluate the fatigue state of CFRP structures by means of evaluating the surface roughness variation due to fatigue damage. The surface roughness is a property that can be measured in the field by optical techniques such as speckle and could be a useful tool for structural health monitoring. The relation between surface roughness and fatigue life has been assessed on CFRP test specimens. A tensile fatigue load with an R=0.1 (T-T) and a maximum load of 60% of the material ultimate strength has been applied. The surface roughness of the specimens has been determined from the surface topography measured by a high precision confocal microscope. Results show that the surface roughness of the specimens increases with the accumulation of fatigue cycles in such a way that the roughness could be taken into account as a fatigue damage metrics for CFRP. © (2013) Trans Tech Publications.
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    Ítem
    Detection of structural damage and estimation of reliability using a multidimensional monitoring approach
    (SAGE PUBLICATIONS LTD, 2018-04-01) Ortiz J.O.; Betancur G.R.; Gómez J.; Castañeda L.F.; Zajsc G.; Gutiérrez-Carvajal R.E.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)
    Many structural elements are exposed to load conditions that are difficult to model during the design phase, such as environmental uncertainties, random impacts, and overloading, amongst others, thus increasing unprogrammed maintenance and reducing confidence in the reliability of the structure in question. One way to deal with this problem is to monitor the structural condition of the element. This approach requires supervising several signals coming from critical locations and then performing an accurate condition estimation of the element in question based on the data collected. This study implements a method to diagnose and evaluate the reliability of the bolster beam structure of the railway vehicle during a fatigue test. The results show that multidimensional monitoring not only diagnoses the element accurately but also results in correct estimation of reliability. © 2017, © IMechE 2017.