Multiaxial loading on a 3D woven carbon fiber reinforced plastic composite using tensile-torsion tests : Identification of the first damage envelope and associated damage mechanisms

Abstract

This study focuses on the experimental identification of the first damage envelope in a 3D woven composite with polymer matrix, under multi-axial loadings including combined inplane tension and out-of-plane shear loadings (σ-τ envelopes). Proportional Tensile-Torsion tests on rectangular bars were performed to induce different multi-axial stress states. To enable envelopes identification, onset of the first damage has been evaluated thanks to the correlation of various and complementary investigation measurement techniques, such as Stereo-Digital Image Correlation (Stereo-DIC), Acoustic Emission (AE) and in-situ microscopic observations. In addition, a specific data reduction process has been used to manage accurate quantification of the stress state induced by the multi-axial loadings. Based on these findings, both σ 11-τ 13 and σ 22-τ 23 envelopes were identified on a 3D woven 2 composite material with polymer matrix. Using microscopic observations, damage mechanisms (type and localization) related to the multi-axial loadings were identified. In addition, thanks to the strain fields measured by the Stereo-DIC on the material surface, particular relations between the multi-axial loadings and the 3D woven architecture have been established.

Experimental Linear and Nonlinear Vibration Methods for the Structural Health Monitoring (SHM) of Polymer-Matrix Composites (PMCs): A Literature Review

“…In Figure 5, we can observe the evolution of damages during a tensile test. Recently, many 3D woven composites have been developed for particular applications (aerospace and defense domains), and some studies of their mechanical properties have been proposed [36].…”

Understanding the damage mechanisms in 3D layer-to-layer woven composites from thermal and acoustic measurements

“…Illustration of a typical woven composite architecture. 42 the average applied stress, as the real stress distribution is heterogeneous due to the complex microstructure of the material.…”

“…The intra-yarn fibre volume fractions are equal to 0.8 and 0.88 for the yarns in the warp and weft direction, respectively.

Figure 1.Illustration of a typical woven composite architecture. 42

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Mechanical Properties Degradation of Fiberglass Tubes during Biaxial Proportional Cyclic Loading

“…Recent testing systems allow the implementation of a complex stress-strain state by loading cruciform specimens in two orthogonal axes [30][31][32], the tension of tubular specimens under the internal pressure [33,34], the torsion of tubular specimens with bending [35][36][37][38], and tension-compression with torsion [39][40][41]. Experimental studies of the degradation of the composites' mechanical properties under multiaxial cyclic loading have been presented previously [42][43][44].…”