Comparison of fatigue limits obtained on thermoplastic composites from SN curve & self-heating method

Comparison of fatigue limits obtained on thermoplastic composites from SN curve & self-heating method

Catherine Peyrac Fabien Lefebvre Ophélie Westphal Laurent Gornet 

Cetim, 52 avenue Félix Louat, 60304 Senlis

Ecole Centrale Nantes

30 April 2016
| Citation

To achieve weight reduction of structures, composite materials are used extensively in different industrial applications as aerospace and automotive. Their high mechanical performances and good fatigue durability offer advantages compared to more traditional materials. To be able to design composite parts, it is necessary to characterize their fatigue behavior and specifically to evaluate fatigue limit. All fatigue tests generally used for this determination take long time and are potentially very costly. In this paper we propose to apply on thermoplastic composites, the self-heating method, which has been developed and validated initially on carbon/epoxy composite materials.The material under consideration is a woven made of carbon fibers and PA66 matrix. Fatigue tests are conducted on two stacking sequences ([0°] and [+/-45°]). The results show that during self-heating tests at room temperature, the mechanisms leading to the increase in temperature are different compared with those observed in thermoset matrix composite systems. This means that a new analysis of the results must be developed to obtain the limit of fatigue. The fatigue limit obtained with this method, is successfully compared with results from classical SN curves.


fatigue, thermoplastic composites, self-heating

1. Introduction
2. Materials
3. Results and Discussion
4. Conclusion

Chrysochoss A., Louche H. (2000). An infrared image processing to analyse the calorific effect acccompagnying strain localization. International journal of engineering science, vol. 38 (16), p. 1759-1788.

Doudar C., Calloch S., Hild F., Cugy P., Galtier A. (2004). Identification of the scatter in high cycle fatigue from temperature measurements. Comptes Rendus Mécanique, vol. 332, p. 795-801.

Fargione G., Geraci A., La Rosa G., Risitano A. (2002). Rapid determination of fatigue curve by the thermographic method. International Journal of Fatigue, vol. 24, p. 11-19.

La Rosa G., Risitano A. (2000). Thermographic methodology for rapid determination of the fatigue limit of materials and mechanical components. International Journal of Fatigue, vol. 22, p. 65-73.

Westphal O. (2014). Analyse thermomécanique de l’endommagement en fatigue de stratifié carbone/époxy : détermination de la limite d’endurance par essais d’auto-échauffement. Thèse de Doctorat, Ecole Centrale Nantes.