Honeycomb damage detection in a reinforced concrete beam using frequency mode shape regression

The objective of the study was to propose a technique to determine the location and severity of honeycomb damage in a reinforced concrete beam using frequency mode shape regression focusing on minimal data. Simply supported reinforced concrete beams were constructed with two different volumes of honeycomb materials implanted at mid-span of the beams. The technique necessitated the performance of linear and eigen analyses on a control beam, and nonlinear analysis on the test beams with damage. Local stiffness indicators obtained from regression using the Levenberg–Marquardt algorithm and residuals from regression of the frequency mode shapes using the Chebyshev series rational and transformation and application into the fourth order centered finite divided difference formula were utilized. Both approaches were successful in determining the location of the honeycomb damage. The Chebyshev series rational method was unable to determine the severity of damage.

► Regression using LMA can determine location and severity of honeycomb in RC beam.
► Regression using the Chebyshev’s series rational can detect location of damage.
► The Chebyshev’s series rational need an index to indicate severity of damage.