Thermal phenomenon of glass fibre composite under tensile static and fatigue loading

Abstract

The aim of this study is to understand the thermal phenomenon of unidirectional Glass Fibre Reinforced Polymer (GFRP) composite under static and fatigue (tensile) loads. This study used a rectangular shaped GFRP composite and consisted of specimens with and without a circular notch. Under static test, the constant displacement rate was applied. Under fatigue test, frequency and amplitude of stress were explored to study the fatigue properties and damage evolution of the specimen. Thermography was used in real-time observation to obtain the temperature profile on the external surface of the specimens. This experimental method showed that the thermal phenomenon gave a good detection of the damage appearance of GFRP material under static loading. Moreover, thermal phenomenon gave a good correlation with the energy dissipation under fatigue loading. Thermal phenomenon successfully determined the high cycle fatigue strength of GFRP composite. This study concluded that thermal phenomenon observed by Infra-Red (IR) camera has successfully demonstrated the damage propagation and the strength behaviour of GFRP composite due to tensile loading in both static and fatigue conditions. The IR camera can then be used to determine the damage evolution and the strength prediction based on the thermal phenomenon on the external surface of the GFRP composite.

Determination of Strain Limits for Dimensioning Polyurethane Components

“…As described in [ 28 , 29 , 30 ], the heating of the test specimen can be detected by means of thermographic analyses and considered in connection with the evaluation of viscoelastic effects or damage processes (under progressive load). For example, in [ 26 , 27 , 31 ], the temperature change in a composite material is measured by means of an infrared (IR) camera system and used to define a dimensioning limit for cyclically tensile stressed test specimens. Based on the results of these studies, the test method is validated within the scope of this contribution by means of an IR camera of the type ImageIR 8300 (InfraTec GmbH, Dresden, Germany), which is used to detect the heating of the tensile specimen in the DMTA during the mechanical test ( Figure 6 ).…”

kf Evaluation in GFRP Composites by Thermography

“…Despite the metallic materials case, a lot of scientific researches consider the fatigue damage monitoring by thermal methods in composite materials [11][12][13][14][15][16][17], but only some of these attempt to evaluate the fatigue limit [13,16]. The application of IR-thermography to different glass and basalt fibre-reinforced composite materials, to relate their thermal response to the mechanical behaviour, is presented in [11].…”

“…A technique to pass from temperature information to distribution of heat sources on the composites surface to monitor the damage evolution of some carbon/epoxy composite specimens during a fatigue test has been proposed [16]. Only one study analysed the influence of a particular type of notch as a central hole [17] but no study has analysed the presence of notch with different geometries in composites. The aim of this previous study was to understand the damage evolution of unidirectional GFRP specimens with and without a circular notch under static and fatigue loads, by observing the thermal phenomena on the external surface of the GFRP composite [17].…”

“…Only one study analysed the influence of a particular type of notch as a central hole [17] but no study has analysed the presence of notch with different geometries in composites. The aim of this previous study was to understand the damage evolution of unidirectional GFRP specimens with and without a circular notch under static and fatigue loads, by observing the thermal phenomena on the external surface of the GFRP composite [17].…”

Damage Behaviour and Stress Concentration Factor of Open Hole Tensile (OHT) Glass Fibre Reinforced Polymer (GFRP) Composites

“…where, α1 and α2 are the coefficients of thermal expansion (μm/m o C), Cp is the specific heat at constant pressure (J/g o C), ρ is density (g/cc) and Δσ is the change in stress (N/m 2 ) where subscripts 1 and 2 denote the longitudinal and transverse to fibre directions. Furthermore, most research works based on thermography on composite material has shown that thermal analyses can indicate the damage location on the specimen surface and successfully detected the damage formation and propagation based on the temperature evolution under static loading conditions [13,14,15,16,17,18,19].…”