Papers by Author: Alexander Tessler

Abstract: Two finite-element-based, full-field computational methods and algorithms for use in Structural Health Management (SHM) systems are reviewed. Their versatility, robustness, and computational efficiency make them well suited for real-time, large-scale space vehicle, structures, and habitat applications. The methods may be effectively employed to enable real-time processing of sensing information, specifically for identifying three-dimensional deformed structural shapes as well as the internal loads. In addition, they may be used in conjunction with evolutionary algorithms to design optimally distributed sensors. These computational tools have demonstrated substantial promise for utilization in future SHM systems.

Abstract: The paper describes an on-going research effort aimed at detecting the presence of delamination damage in composite panels based upon their higher-frequency structural response. Two alternative damage indexes are examined that facilitate the identification of the location and extent of delaminations. The damage indexes do not require vibration measurements to be performed on the undamaged structure. Use is made of the bending and twisting curvatures corresponding to the higher-frequency mode shapes that are post-processed via two different smoothing techniques. The modal data are obtained via finite element models based on Mindlin theory and including delaminations. These are introduced using a sub-laminate strategy that permits multiple damages to be modelled through the thickness. Various delamination sizes and locations are examined with a random noise superposed on the data in order to ascertain the degree of sensitivity of the damage index to the noise in the experimental data.