Virtual testing of low-velocity impact response of a composite laminate - from analytical to high-fidelity modelling

icaf2023 Tracking Number 126

primary strategy to ensure the structural integrity of composite structures for aircraft design, certification, and sustainment is based on costly experimental campaigns. Virtual testing tools are essential to assist with materials screening and design processes. Advanced virtual testing tools offer potential to transform aircraft development and certification towards certification by analysis, and then they can be integrated as a part of digital twin for individual aircraft tracking and management. Virtual structural testing may include a range of modelling and simulation tools, from analytical, low order to high order numerical tools, to predict structural responses and performance. Lower order tools are often computationally efficient and require less specialized expertise to run the tools. Such tools are often used in preliminary designs allowing extensive trade-off studies and layup optimization. Lower order tools are often well suited for quick decision making to assess the effect of damage on airworthiness. However, such tools come with concerns of their ability to provide adequate prediction for design and maintenance. High-fidelity finite element models are proven to provide accurate, physics-based prediction of composite progressive damage. Although great progress has been made in achieving improved fidelity of composites modelling, there remains challenges in achieving computational efficiency. It can be prohibitively expensive to run high-fidelity modelling of composite structures, thus rendering it impractical for some applications. This study offers an assessment of modelling strategies to support concession decision making for aircraft designers, operators and maintenance facilities. A trade-off study between the accuracy and the computational costs of modelling methods was conducted based on prediction of damage resistance of IM7/977-3 composite panels subject to low-velocity impact. Simulation was performed using an analytical solution, a continuum mechanics based finite element model (FEM), and a high-fidelity FEM based on an integrated discrete damage and continuum mechanics-based approach. The predicted damage size and impact response were compared with experiments to assess the predictive accuracy and computation costs. Keywords: Virtual Testing, Composites; Impact damage; Analytical, Finite element analysis;