CURRENT/RECENT RESEARCH HIGHLIGHTS

Wave Slamming of Sandwich Composite Ship Hulls

·         The fluid-structure interaction of composite materials is poorly understood but highly relevant in the aerospace and marine industry.  A research program is ongoing to understand the damage mechanisms in the composite materials ship hulls subject to repeated water slamming.  This work continues to provide unique observations.

Damage Assessment in Composites

·         There is a surprising lack of viable instrumentation to uncover the presence of damage in sandwich composites, and furthermore, no single piece of instrument has the capability to capture various damage signals especially under dynamic loading.  Therefore, a neural network based technique is developed that takes partial signatures from various sensors, such as acoustic emission, strain gauge and thermography, etc. and constructs a complete damage scenario. 

Vibration Fatigue Testing

·         Composite material fatigue lifetimes are highly stochastic in nature which makes the whole process prohibitively costly.  Therefore, a novel vibration based technique is developed as a viable substitute to conventional fatigue testing that has the potential of up to an order of magnitude savings in terms of time and revenue. 

Corrosion Fatigue

·         Synergistic effects of marine environment and stress are detrimental to high strength alloys, commonly used in aircraft and marine industry.  The study focuses on the highly complex mechanisms of crack initiation, propagation and catastrophic failure in ultra-high strength aluminum and steel alloys under the combined action of corrosive marine environment and the applied loading.

·         Sandwich composites are increasingly used in marine structures due to their inherent strength to weight superiority.  However, mismatch in the constituent properties can lead to premature and unpredictable failure especially when aggressive marine environment is present.  A research program is currently being carried out to understand the role of sea water on the integrity of sandwich composites. 

Biomechanics

·         Modeling of joint movement remains a daunting task due to the immensity of active agonistic/antagonistic muscular engagement, passive role of ligaments and complex geometrical rolling/gliding movement of the contacting bones.  The current focus of research is to exploit continuum mechanics in order to understand the sequential engagement of musculature in common joint movements.