Modelling of guided wave propagation for detecting delamination in large composite structures

Shoja, Siavash; Chalmers University of Technology; Sweden

Shoja, S.; Chalmers University of Technology; Sweden
Berbyuk, V.; Chalmers University of Technology; Sweden
Boström, A.E.; Chalmers University of Technology; Sweden

ID: ECNDT-0292-2018
Download: PDF
Session: Guided Waves techniques 2
Room: G3
Date: 2018-06-14
Time: 16:00 - 16:20

One of the main modes of failure in composite structures is delamination. Its detection is usually performed using a non-destructive testing methods, for instance ultrasonic waves. In large composite structures such as wind turbine blades, guided waves (GW) can be used as a detection tool due to their ability of propagating along long distances. Computational modelling of GW propagation in composite structures is one of the ways of studying their applications. However in cases of large structures, computational modelling becomes more challenging due to their large dimensions and small element size. One of the aims of this study is to identify the challenges in computational modelling of guided wave propagating in delaminated composite structures and propose approaches to overcome them. In the first part three types of finite element models of GW propagation in composite structures with delamination are introduced. The models are based on layerwise and equivalent single layer methods for modelling the composite plate and duplicated node and stiffness reduction methods for modelling the delamination. The models are compared by comparing the simulation results in different case studies and their advantages and limitations are mentioned. The second part is studying GW in sandwich material which is one of typical types of structures in large composite components. Finally in the third part the methods introduced in the previous parts are applied on FE modelling of GW propagation in an 8 meters long carbon fibre blade for a wind turbine with the aim of delamination detection.