Numerical approach to disbonds in bonded composite Single Lap Joints: Comparison between Carrera Unified Formulation and classical Finite Element modeling.

The scope of this study is the monitoring of the adhesion integrity of composite Single Lap Joints (SLJs) through the assessment of the M U L 2 CODE, software developed by the M U L 2 Research Group - Department of Mechanical and Aerospace Engineering of Politecnico di Torino. The M U L 2 CODE is implemented through the Carrera Unified Formulation (CUF) for 2D structures based on Hierarchical Legendre Expansion (HLE) polynomials. An efficient method for the Structural Health Monitoring (SHM) of bonded composite joints is experimentally verified and simulated by commercial FE software and by the CUF approach, in order to reduce the computational cost of analyses: using transient excitations via toneburst signals, the structural health of damaged SLJ is analytically, experimentally and numerically evaluated. The interaction mechanism between the waves traveling through the investigated specimens is numerically simulated with a simple Finite Elements (FE) model and it is solved via M U L 2 CODE and commercial software Ansys Workbench (with 2D and 3D models), respectively. Experimental campaigns data are compared with analytical, CUF and Ansys results demonstrating the consistence of the M U L 2 formulation that is computationally simpler, but very efficient for the joint analysis. The presented and discussed CUF application is able to quantify with a high accuracy the debonding extension in the damaged SLJ, simply tuning the excitation frequency of the SHM technique. • Elastic waves interference is evaluated by using analytical approach, experimental data, CUF and Ansys simulations. • The method is tested on a composite single lap joint, simple experimental set-up representative of an actual scenario. • A good agreement between experiments and simulations confirmed the validity of the proposed method. • The CUF approach provides finer results with lower elapsed computational time respect to the Ansys FE model. [ABSTRACT FROM AUTHOR]