Rapid Determination of the High Cycle Fatigue Limit Curve of Carbon Fiber Epoxy Matrix Composite Laminates by Thermography Methodology: Tests and Finite Element Simulations

Abstract

International audienceSelf-heating measurements under cyclic loading allow a fast estimation of fatigue properties of composite materials. The tensile fatigue behavior of a high stress carbon fiber epoxy-matrix composite laminates is examined at room temperature. Tension- tension cyclic fatigue tests are also conducted under load control at a sinusoidal frequency of 5 Hz to obtain high-cycle fatigue stress curves (S-N). The fatigue limits of the different composite lay-ups tested were successfully compared with data resulting from the self-heating test method on the same laminates. This comparison reveals a good agreement between the two methods dedicated to stress fatigue limit determination. In addition, a tomographic analysis is used to perform comparisons at the microscale between both fatigue methods. The nonlinear heat transfer laminate theory is used for self-heating tests simulation. Self-heating simulations involving conduction, convection, and boundary radiation are performed with the Finite Element code Cast3 M

The fatigue of carbon fibre reinforced plastics - A review

“…The build up of heat in CFRP under cyclic loads is a point of importance as heat can affect the mechanical behaviour, and can also instigate chemical changes to the polymer matrix. Thermography can be used to monitor heat build up in CFRP, [44,45,35]. When cyclically loading CFRP under high loads and frequencies, hysteresis loops can be observed to increase in area.…”

Failure of Fiber-Reinforced Composites

“…The second type of heat source is friction inside the material or between the support and the test specimen. While the generation of heat due to the latter is a general problem especially during fatigue testing of composites [199][200][201], the friction inside the material is key to assist in interpretation of material failure. During periodic cyclic loading experiments, existing crack surfaces can rub against each other and therefore generate a noticeable amount of heat.…”

Effect of heat conduction on rapid evaluation of fatigue limit based on temperature evolution due to cyclic loading

“…The numerical resolution of the thermal problem allows determination of the time evolution of the temperature fields in the specimen. Gornet et al (2013) tried to determine fatigue limit of carbon fiber epoxy matrix laminated composites under cyclic loadings by self-heating measurements using experiment and simulation. It is reported that the proposed self-heating test method combined with tomography and finite element simulations confirms that the fatigue limit of composite materials could be measured in few hours without classical fatigue test campaigns.…”