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Acoustic emission for fatigue damage characterization in metal plates Vrije Universiteit Brussel

Dimitrios Angelis, E. Z. Kordatos, Theodore E. Matikas

Acoustic emission (AE) supplies information on the fracturing behavior of different materials. In this study, AE activity was recorded during fatigue experiments in metal coupons. The plates were characterized by a symmetric V-shape notch and were loaded in tension-tension fatigue until final failure with concurrent AE activity monitoring. The relatively broad bandwidth of the sensors enabled the recording of a wide range of frequencies up to ...

An integrated NDT approach for damage assessment of CFRP composites under complex static and fatigue loads Vrije Universiteit Brussel

Kalliopi-Artemi Kalteremidou
Carbon fiber polymer composite materials are considered one of the most promising lightweight candidates for load bearing applications in many engineering fields. Damage during loading of composite materials can appear under many different modes, like for instance matrix cracking, interlaminar delaminations and fiber breakage. Due to the anisotropy of composites, leading to complex stress states in the individual plies, the damage sequence is ...

Residual properties and damage evolution of flax-epoxy composites subjected to fatigue loading KU Leuven

Farida Bensadoun, Katleen Vallons, Ignace Verpoest, Aart Willem Van Vuure
Flax fibre-based composites have seen increased use in recent years and new questions have arisen concerning their longevity. Thus, it is necessary to assess the long term properties such as fatigue and damage development. The present study focuses on the characterization of the residual properties of flax-epoxy composites subjected to fatigue loading as well as the damage development. Understanding these properties would allow easier ...

Acoustic emission for fatigue damage monitoring in cross-welded aluminum plates Vrije Universiteit Brussel

Dimitrios Angelis, Ioannis Spyridon, Theodore Matikas
Acoustic emission (AE) technique is commonly applied in different materials in order to evaluate their internal fracturing condition in real time. Apart from the number of acquired signals, which are correlated to the number of active cracking sources, qualitative features of the acoustic waveforms shed light in the dominant fracturing mode. This is due to the fact that the emitted waves depend on the relative motion of the crack sides at each ...

Monitoring of fatigue damage in metal plates by acoustic emission and thermography Vrije Universiteit Brussel

E. Z. Kordatos, Dimitrios Angelis, Theodore E. Matikas

Acoustic Emission (AE) supplies information on the fracturing behavior of different materials. In this study, AE activity was recorded during fatigue experiments in metal CT specimens with a V-shape notch which were loaded in fatigue until final failure. AE parameters exhibit a sharp increase approximately 1000 cycles before than final failure. Therefore, the use of acoustic emission parameters is discussed both in terms of characterization ...

Multiaxial damage characterization of carbon/epoxy angle-ply laminates under static tension by combining in situ microscopy with acoustic emission Vrije Universiteit Brussel

Kalliopi-Artemi Kalteremidou, Brendan Murray, Eleni Tsangouri, Dimitrios Angelis, Danny Van Hemelrijck, Lincy Pyl
Investigating the damage progression in carbon/epoxy composites is still a challenging task, even after years of analysis and study. Especially when multiaxial stress states occur, the development of damage is a stochastic phenomenon. In the current work, a combined nondestructive methodology is proposed in order to investigate the damage from the static tensile loading of carbon fiber reinforced epoxy composites. Flat angle-ply laminates are ...

FE-modeling of damage of twill carbon/epoxy composite on meso-scale, materials characterization and experimental verification KU Leuven Ghent University

Stepan Lomov, Ignace Verpoest
Aim of this work is to evaluate the damage in twill carbon/epoxy composites on meso-scale level (fabric unit cell level). Averaged stiffness, Poisson ratios of pre- and post damage phase are calculated based on numerical homogenization technique with periodic boundary conditions (PBCs). The static strengths and initiation of the damage are calculated and validated by experiments. The anisotropic stiffness degradation model is implemented into ...