Structural Damage Detection Based on Modal Parameters Using Continuous Ant Colony Optimization

Aditi Majumdar,Damodar Maity,Bharadwaj Nanda,Dipak Kumar Maiti

doi:10.1155/2014/174185

Abstract

A method is presented to detect and quantify structural damages from changes in modal parameters (such as natural frequencies and mode shapes). An inverse problem is formulated to minimize the objective function, defined in terms of discrepancy between the vibration data identified by modal testing and those computed from analytical model, which then solved to locate and assess the structural damage using continuous ant colony optimization algorithm. The damage is formulated as stiffness reduction factor. The study indicates potentiality of the developed code to solve a wide range of inverse identification problems.

Highlights

Structural health monitoring (SHM) has become an important area of research within the civil, mechanical, aerospace engineering community in recent years
In practice for damage identification the natural frequencies and mode shapes are identified from modal testing, and it is assumed that the finite element model representing the structure will provide the same modal values as those identified from modal testing
In order to simulate the experimental natural frequencies in a realistic way, 1% random noise is added to the numerical natural frequency and 10% random noise is added to the numerical mode shape

Summary

Introduction

Structural health monitoring (SHM) has become an important area of research within the civil, mechanical, aerospace engineering community in recent years. A damage detection problem using changes in natural frequencies and/or mode shapes is basically an inverse problem, where one objective function, defined in terms of discrepancies between the vibration data identified by modal testing and those computed from analytical model, is minimized or maximized. These relationships are very complex involving a large number of local optima, making the problem too difficult to be solved by conventional optimization algorithms such as conjugate gradient method. Some numerical experimentation is carried out to demonstrate the efficiency of this method for wide range of practical problems such as beam and plane frame as well as space frames

Theoretical Background

Results and Discussions

Damage Assessment in Beam Type Structure

Damage Detection of a Plane Frame Structure

Conclusion