An investigation of the influence of macroscopic heterogeneity on the thermoelastic response of fibre reinforced plastics

A generalised approach to the calibration of orthotropic materials for thermoelastic stress analysis

“…This was also confirmed in a study on pultruded composite materials [14]. Pitarresi et al [15] studied woven composite material and concluded that the thermoelastic response was generated by strain transfer into the resin-rich surface layer. A number of quantitative studies have been carried out on composite structures [16][17][18] by deriving a calibration constant; however a generalised calibration routine has not been developed.…”

“…(3) in terms of strain and use this as a basis for calibration, as under in-plane loading the strain is constant through the thickness of a multidirectional laminate and can be measured using extensometers or strain gauges. In [10,13,14,15] strain formulations are used to assess the thermoelastic response for specific materials, but the issue of calibration is not addressed. The objective of the present work is to devise a general calibration routine for orthotropic composite laminates based upon laminate strains rather than the surface lamina stresses.…”

On the fatigue response of a bonded repaired aerospace composite using thermography

“…However, cyclic mechanical loading induces both thermoelastic and thermoplastic effects on the tested component. Thermoelastic phenomena are solely present when the material is stressed in the elastic region whist thermoplastic phenomena [18] are cumulatively added to the thermomechanical coupling beyond the elastic region, after irreversible processes take place [36]. In the case of cyclic loading, thermoelastic phenomena are expected to affect the material's mean temperature during testing reflecting the thermo-sensitivity of the material or the coupling between the material's mechanical and thermal states.…”

“…Other studies assessing thermomechanical mechanisms in dynamically tested composites have also been reported by Wong [32], Cunningham et al [33] and Refs. [34][35][36]. Myriounis et al [9] examined the fracture mechanics of metal-matrix composites through the monitoring of 'intrinsic energy' dissipated by thermomechanical coupling during fatigue mechanical loading [37].…”

Material Properties for Quantitative Thermoelastic Stress Analysis of Composite Structures

“…Since the resins used in composite materials are poor conductors, even a thin surface resin layer can act as a 'strain witness' [3,4]. In these cases the thermoelastic response from the resin layer can be related to the strains in the laminate by [3,4]:…”