Damage detection using derringer’s function basedweighted model updating method

Aim of this research paper is to present the application of Derringer’s function based weighted model updating method for damage detection in a cantilever beam structure installed near an electric motor. Individual desirability functions have been used to provide scale-free representations of ten sub-objectives of model updating based multi-objective optimization problem. First five vibration modes of beam structure are considered for model updating purpose and hence ten individual desirability functions (sub-objectives) are formulated. Maximization of an individual desirability function leads to minimization of error in corresponding finite element response to which the individual desirability function is attached. Since there are more chances of excitation of those vibration-modes which lie close to the operational frequency of the electric motor; more relative importance is given to such modes by increasing the relative importance index of their individual desirability function. Such kind of relative importance selection is not possible in widely used model updating methods such as response function method. Comparative study is performed for Derringer’s function based non-weighted and weighted model updating methods. Results show that weighted model updating method performs better than its nonweighted counterpart. © The Society for Experimental Mechanics, Inc. 2014.