Application of Modal Analysis in Local Damage Diagnosis of Steel Beam
For one cantilever steel beam, according to the stress concentration principle resulted from the small hole, four small holes were drilled at different positions to form the local damage of the steel beam. The modal tests including the displacement modal and the strain modal were conducted before and after the steel beam was damaged. The test results indicated: from the decreased frequency, one could only judge on the whole that the steel beam had been damaged, but could not determine the detailed damaged positions; the detailed damaged positions of the steel beam were also difficult to be determined by the displacement modal test whether by ripple technique or by hammering technique, but could be determined by the strain modal test by hammering technique, especially under the first order of modal. The research achievements can offer some references for the diagnosis of local damage of engineering structures by the strain modal analysis method.
Z. G. Gong et al., "Application of Modal Analysis in Local Damage Diagnosis of Steel Beam", Applied Mechanics and Materials, Vols. 138-139, pp. 592-597, 2012