Acoustic Emission And Acousto Ultrasonics On Aromatic Polymer Composites

In this book, two kinds of analysis based on acoustic emission recorded during mechanical tests are investigated. In the first, individual, analysis, acoustic signature of each damage mechanism is characterized. So with a clustering method, AE signals that have similar shapes or similar features can be group together into a cluster. Afterwards, each cluster can be linked with a main damage. The second analysis is based on a global AE analysis, on the investigation of liberated energy, with a view to identify a critical point. So beyond this characteristic point, the criticality can be modeled with a power-law in order to evaluate time to failure.

The use of acoustic emission to characterize impact damage in composite structures is being performed on composite bottles wrapped with graphite epoxy and kevlar bottles. Further development of the acoustic emission methodology will include neural net analysis and/or other multivariate techniques to enhance the capability of the technique to identify dominant failure mechanisms during fracture. The acousto-ultrasonics technique will also continue to be investigated to determine its ability to predict regions prone to failure prior to the burst tests. Characterization of the stress wave factor before, and after impact damage will be useful for inspection purposes in manufacturing processes. The combination of the two methods will also allow for simple nondestructive tests capable of predicting the performance of a composite structure prior to its being placed in service and during service. Workman, Gary L. (Principal Investigator) and Walker, James L. Marshall Space Flight Center...

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Durability and Life Prediction in Biocomposites, Fibre-Reinforced Composites and Hybrid Composites focuses on the advanced characterization techniques used for the analysis of composite materials developed from natural fiber/biomass, synthetic fibers and a combination of these materials used as fillers and reinforcements to enhance materials performance and utilization in automotive, aerospace, construction and building components. The book presents key aspects of fracture and failure in natural/synthetic, fiber reinforced, polymer based composite materials, ranging from crack propagation, to crack growth, and from notch-size effect, to damage-tolerant design. Written by leading experts in the field, and covering composite materials developed from different natural fibers and their hybridization with synthetic fibers, the book's chapters provide cutting-edge, up-to-date research on the characterization, analysis and modelling of composite materials. Contains contributions from leading experts in the field Discusses recent progress on failure analysis, SHM, durability, life prediction and the modelling of damage in natural fiber-based composite materials Covers experimental, analytical and numerical analysis Provides detailed and comprehensive information on mechanical properties, testing methods and modelling techniques