Nonlinear acoustic fast and slow dynamics of damaged composite materials: correlation with acoustic emission
Slow and fast dynamics in the elastic response of damaged materials to external excitations show evidence of an anomalous hysteretic elastic behavior. Experimental observations may be used to detect and eventually characterize damage existing in structural components. Here we analyze the evolution of nonlinear dynamic behavior of a polymer-based composite (SMC) and concrete. More particularly, nonlinear slow dynamics parameters have been found to be very sensitive to damage evolution for both materials. Besides, acoustic emission monitoring is used to calculate the elastic energy released by SMC during a gradual increasing damage procedure. Interesting logarithm-like evolution of the followed nonlinear parameters as a function of the calculated energy is found. A classification of the calculated acoustic emission signal is proposed to understand the contribution of the different damage mechanisms to the evolution of the nonlinear behavior of SMC.
KeywordsAcoustic Emission Resonance Mode Damage State Slow Dynamic Concrete Sample
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