Localization and quantification of damage in a space truss model using modal strain energy

Cesar J. Carrasco; Roberto A. Osegueda; Carlos M. Ferregut; Mike Grygier

doi:10.1117/12.274641

23 May 1997 Localization and quantification of damage in a space truss model using modal strain energy

Cesar J. Carrasco, Roberto A. Osegueda, Carlos M. Ferregut, Mike Grygier

Proceedings Volume 3043, Smart Structures and Materials 1997: Smart Systems for Bridges, Structures, and Highways; (1997) https://doi.org/10.1117/12.274641
Event: Smart Structures and Materials '97, 1997, San Diego, CA, United States

Abstract

This paper addresses the issue of localizing and quantifying damage using changes in the vibrational characteristics of structures. The method considers the mode shapes of the structure pre- and post-damage measured via modal analysis. Values of the modal shapes are used to compute the strain energy distribution in the structural elements. Using the assumption that the element modal strain energy is the same pre- and post-damage, and characterizing the damage as a scalar quantity of the undamaged stiffness matrix, an expression is obtained for element damage factors that quantify the magnitude of the damage for each mode shape. Due to numerical instabilities in the computation of this expression, filters are applied that overcome some of the instabilities but reduce the true amplitude of damage. The modified-filtered expression was very effective in localizing the actual damage. After localization, the magnitudes of damage are computed using the original unfiltered expression. The method is tested using experimental data from a 3D scale model of a space structure, subjected to 18 different damage scenarios. The damage forms consist of a 180 degree cut (Type I), a 50 percent reduction of the area over one-third the element length (Type II), and a complete cut through the element section (Type III). These types of damages correspond to magnitudes of (alpha) equal to -0.17, -0.5, and -1.0 respectively. The method is ale to detect Type I damage for only one of four cases, Type II for all the three cases and Type III damage for all single and double-location cases, excluding the cases that involves a damage insensitive element.

Citation Download Citation

Cesar J. Carrasco, Roberto A. Osegueda, Carlos M. Ferregut, and Mike Grygier "Localization and quantification of damage in a space truss model using modal strain energy", Proc. SPIE 3043, Smart Structures and Materials 1997: Smart Systems for Bridges, Structures, and Highways, (23 May 1997); https://doi.org/10.1117/12.274641

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available