COMPONENT-WISE 1D MODELS FOR DAMAGED LAMINATED, FIBER-REINFORCED COMPOSITES

The structural analysis of damaged composite structures requires high fidelity models to detect very accurate displacement, strain and stress fields. In particular, local effects and 3D stress fields have to be dealt with. The proper modeling of multiscale components – layers, fibers and matrix – enhances the accuracy of computational models to a great extent. To date, 3D solid finite elements represent the most reliable tool for this kind of analyses. However, such finite elements can lead to very cumbersome numerical models. In other words, the accurate structural analysis of complex structures is quite impossible due to the very high number of degrees of freedom that is necessary. This paper presents free vibration analyses of damaged composite structures via an innovative approach that is based on 1D (beam) advanced models. The present 1D FEs stems from the Carrera Unified Formulation (CUF) and provide a Component-Wise (CW) modeling. In a CW model, each component of a complex structure is modeled through the refined 1D CUF models. A detailed physical description of the real structure is achieved because each component can be modeled with its material characteristics, and no homogenization techniques are required. Furthermore, although 1D models are exploited, the problem unknown variables are located on the physical surfaces of the real 3D model, and no artificial surfaces or lines have to be defined to build the structural model. The CW can lead to a multiscale approach for composites since each typical component of a composite structure - fibers, matrix, plies - can be modeled through the 1D CUF models. Different scale components can be assembled straightforwardly without ad hoc coupling techniques. The adoption of 1D models enhances the multi-dimension coupling capabilities and reduces the computational costs to a great extent. The computational cost reduction in terms of total amount of DOFs ranges from 10 to 100 times less than shell and solid models, respectively. In this paper, damaged composite structures are analyzed using the CW approach. Free vibration analyses are carried out, and comparisons against classical approaches are provided to show the enhanced capabilities of the present approach to providing 3D-like accuracy with very low computational costs.