Study of Defect Coalescence in Heterogeneous Material Systems using Broad Band Dielectric Spectroscopy.
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Date
2017-11Author
Vadlamudi, Vamsee
Elenchezhian, Muthu Ram Prabhu
Banerjee, Priyanshu Kumar
Raihan, Rassel
Reifsnider, Kenneth
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Show full item recordAbstract
Composite materials are essential for many modern applications, including
airplanes and cars, energy conversion and storage devices, medical prosthetics, and
civil structures. Detecting the initiation, growth, accumulation, and coalescence of
micro-damage in these heterogeneous materials and predicting the onset of
component failure using conformal Broadband Dielectric Spectroscopy (BbDS) is a
promising area of ongoing research. Recently, the authors have developed the critical
path concept and Heterogeneous fracture mechanics concept that depicts the effect
of defect nucleation, growth, coalescence, and fracture plane development and
correlation of these damage mechanisms to change in dielectric response
respectively. Current research applies those concepts to detect the damage mode and
the critical fracture path (conduction path) that leads to eventual failure. Also, the use
of BBDS to detect the weak adhesion bonding is proposed, where the change in
dielectric properties as a function of the frequency of the applied potential through
the thickness of the sample is measured in the vicinity of the weak region. It is
observed that at low frequency the gradient in the potential indicates a spike which
marks the charge concentration around the imperfect region.