Extreme dynamic loading of aerospace composite structures

EXTREME Dynamic Loading – Pushing the Boundaries of Aerospace Composite Materials Structures

Composite materials are of fundamental importance to current and future aircraft structures, where high specific properties and integration of multiple functionalities are essential for improvements in weight, fuel efficiency, reduced CO2 emissions, and certification costs.

However, these materials are vulnerable to extreme dynamic unexpected loads, such as blade off events in a jet engine, bird strikes or foreign object damage (hail, runway debris, etc.), which may result in unpredictable complex localized damage and a loss of post-impact residual strength.

Consequently, the aim of the EXTREME project was to develop novel material characterisation methods and in-situ measurement techniques, material models and simulation methods for the design and manufacture of aerospace composite structures under extreme dynamic loadings, leading to a significant reduction of weight, design and certification cost. 

EXTREME partners

Funding

The EXTREME project, funded by EU H2020 programme under agreement no. 636549 with a total budget of €5,227,597, was developed together with 13 leading researchers in the aerospace field across Europe to help mitigate the issues related to characterisation and modelling of extreme dynamic loadings in composites.

Objectives

The main objectives of the project within the framework of the overall aim were to develop

• Improved material characterisation techniques allowing for development of new and improved material models, and for damage assessment during and after extreme events.
• Advanced integrated experimental and numerical procedures and guidelines in support of design and certification of aeronautical structures.
• Smart impact sensing concepts for detection of the extreme dynamic loading, including reconstruction, warning of occurrence of extreme dynamic events and associated effects, measurement of failures parameters for the sake of characterisation of new material models.
• Novel and more accurate multiscale and multilevel simulation tools.

The Centre for Assessment of Structures and Materials under Extreme Conditions (CASMEC) contributed to all work packages within the EXTREME project and was the leading academic partner in material model and computational methods development. This included the development of new multiscale anisotropic constitutive models for analysis of dynamic response of composites and the simulation tools improvements, which addressed the challenges such as treatment of mesh dependency, localisation and softening, multiscale modelling using coupled FEM/SPH discretisation, and the alternative treatment of damage and fracture etc.

The ultimate objective of these activities was the improvement of the predictive capabilities of the simulation tools for dynamic response of composites, which are validated for the relevant cases, developed within the consortium by our industrial partners. The CASMEC team was also working on the development of novel material characterisation techniques for dynamic testing, including the plate impact tests for shock loading characterisation, and smart sensing of composite materials, using the embedded optical fibre sensors.

Research outputs

Five journal publications and over 20 conference papers were published from the work done in the Extreme project.

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