Strain estimation in a glass beam using operational modal analysis

Abstract

A potential application of operational modal analysis is the prediction of strain or stress time histories which, on the other hand, are one of the most important sources of uncertainty in fatigue design and remaining fatigue life calculations. This is due to the difficulty of estimating the stiffness, mass and damping properties with accuracy, as well as the use of simplified loading models. In this work, it is proposed a methodology to estimate the strain or stress time histories at any point of a beam, which need the strain mode shapes, expanded using a finite element model and the modal coordinates of the responses, which contain the information corresponding to the damping and the natural frequencies. Experimental tests were carried out on a monolithic glass beam to study the accuracy obtained in the strain mode shapes. © The Society for Experimental Mechanics, Inc. 2013.