A strain energy-based damage severity correction factor method for damage identification in plate-type structures

A strain energy-based damage identification method for plate-type structures is presented. The concepts of a damage location factor (DLF) matrix and a damage severity correction factor (DSCF) matrix, which can be derived from the elemental modal strain energy, are proposed. The damage identification method using the DLF and DSCF is developed for damage localization and quantification in plate-type structures. The method consists of three steps: sensitive mode selection, damage localization, and damage quantification. The proposed method is a response-based damage identification technique which requires the modal frequencies and curvature mode shapes before and after damage. Numerical study demonstrates its viability to correctly detect the damage, approximate the damage area, and estimate the damage severity under high measurement noise and low damage severity conditions. The possibility of damage identification using the partial modal strain energy from the modal strain/curvature mode shape in one direction of plate is also explored based on the numerically simulated data. The method is further implemented on the experimental modal testing data to identify damage at three stages of increasing damage severity on a fiber-reinforced plastic (FRP) sandwich deck panel using a surface-bonded PVDF sensor array. The present DSCF-based damage identification method, as demonstrated in this study, can be used as a viable and effective technique for damage localization and quantification of plate-type structures.

► Novel damage severity correction factor from the elemental modal strain energy is proposed.
► Strain energy-based method is capable of both localizing and quantifying the damage.
► Only using partial modal strain energy makes easier for experimental testing with sensor array.