Paper number 509

INFLUENCE OF THERMALLY INDUCED STRAINS ON SUBSEQUENT CREEP LOADING, USING MICRO RAMAN SPECTROSCOPY

Jan Schjvidt Thomsen and Ryszard Pyrz

Department of Mechanical Engineering. Aalborg University, Pontoppidanstraede 101,
9220 A Aalborg East, DENMARK

Summary

This paper considers the influence of thermal strains induced in PP/carbon fibre model composites after manufacturing cycles. Creep loading was applied to dogbone specimens and the fibre creep strains were measured using micro Raman spectroscopy. A theoretical approach is proposed to determine the creep strain in a. single embedded fibre. The approach is based upon the integration of pointforces at the interface. These are subsequently used in an incremental approach. It is shown that the model predicts the characteristics of the experiments very well. Generally it is seen that the initial residual stress in the fibre is restricting the magnitude of the fibre strain during subsequent creep loading.

Keywords

micro Raman spectroscopy, creep, residual strains, point forces, short fibres.