Numerical and Experimental delamination sizing in an 8 Layer WGF/epoxy composite plate using ultrasonic Lamb waves

Shafiei Alavijeh, Maryam; Shahid Beheshti University; Iran

Alavijeh, M.S.; Shahid Beheshti University; Iran
Soorgee, M.H.; Shahid Beheshti University; Iran

ID: ECNDT-0294-2018
Session: Guided Waves techniques 2
Room: G3
Date: 2018-06-14
Time: 16:20 - 16:40

Composite structures are widely used in aerospace, aeronautics automotive and marine industries due to their effective properties. However, common defects such as delamination which occur in the laminated composite materials can decrease efficiency of systems. Therefore structures need to be monitored. Structural health monitoring using Lamb waves in composite plates is one of the beneficial methods of inspection. In this paper an 8-layer woven glass fiber reinforced epoxy (WGF/epoxy) composite plate has been studied for delamination sizing via ultrasonic guided waves, both experimentally and numerically. Dispersion curves of specific composite plate are extracted by using semi-analytical finite element method (SAFEM) and proper mode and frequencies has been extracted based on less dispersive behavior. Several delamination with different lengths have been placed between 4th and 5th layers. The plate then has been tested with both S0 and A0 Lamb modes. A 3D finite element (FE) model in ABAQUS/Explicit has been built up to investigate sensitivity of delamination size on the signals. It is shown that converted Lamb modes ate delamination tips provide sensitive features for delamination sizing problems. The approximate size of the delamination has been evaluated both numerically and experimentally and results matches closely