Time reversal active sensing using Lamb waves is investigated for health monitoring of a composite structure. In the present work experiments were conducted on a glass/epoxy composite plates to study the time reversal behavior of A0 and S0 Lamb wave modes. PZT wafer sensors were surface bonded to the structure for generation and reception of the Lamb wave modes. Time reversal experiments were f...

Channeling cracks in brittle thin films have been observed to be a key reliability issue for advanced interconnects and other integrated structures. Most theoretical studies to date have assumed no delamination at the interface, while experiments have observed channel cracks both with and without interfacial delamination. This paper analyzes the effect of interfacial delamination on the fractur...

Failures detection in composite laminates is complicated respect to conventional non-destructive testings for metal structures, due their sensibility echoes drown noise depending by the different properties of constituent materials and multi-layered composites structures. The latter, particular, are sensitive impact damage also a low-energy can results severe loss load capacity as result delami...

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 3463 wileyonlinelibrary.com due to their cost effectiveness, lightweight, and high axial strength. [ 3,4 ] However, several drawbacks of these composites remain unresolved, including in-plane delamination [ 4 ] and low damage resistance against out-of-plane impact, [ 3–5 ] despite some demonstrated improvements through approaches such as placing...

Cost-effective and reliable damage detection is critical for the utilization of composite materials. This paper presents part of an experimental and analytical survey of candidate methods for in-situ damage detection of composite materials. Experimental results are presented for the application of Lamb wave techniques to quasi-isotropic graphite/epoxy thin coupons and sandwich beams containing ...

PURPOSE The purposes of this study were (1) to examine whether posterior delamination is hidden to the most commonly used posterior viewing portal compared with differential rotator cuff portals and (2) to observe posterior delamination patterns so that a treatment-based classification system may be proposed. METHODS One-hundred thirty consecutive patients undergoing arthroscopic rotator cuff...

The requirements on aircraft engine design have increased rapidly over the last decades. Future aircrafts engines are expected to be more efficient with lower operation costs and without compromising safety. Concerning the complex requirements for fan systems or fan containments, composite materials are able to fully avail their high potential with regard to a significant weight reduction and a...

Nonlinear effects in vibration responses are investigated for the undamaged composite plate and the composite plate with a delamination. The analysis is focused on higher harmonic generation in vibration responses for various excitation amplitude levels. This effect is investigated using the triple correlation technique. The dynamics of composite plate was modelled using two-dimensional finite ...

Turon’s methodology for determining optimal analysis parameters for the simulation of progressive delamination is reviewed. Recommended procedures for determining analysis parameters for efficient delamination growth predictions using the Abaqus/Standard cohesive element and relatively coarse meshes are provided for single and mixed-mode loading. The Abaqus cohesive element, COH3D8, and a user-...