9 Summary and outlook
The determination of the mechanical properties by means of physical testing is a major
cost driver in the development process of lightweight products. The implementation of
virtual tests based on FE-simulations can be a significant contributor to reducing the development cost. However, composite sandwich structures are characterized by a complicated failure behavior, making reliable predictions via FE-simulations challenging. The
present work addresses this problem by establishing a virtual testing approach for sandwich structures. The approach is based on the building block approach for the development of aircraft composite structures. Its structure therefore reflects the common classification in constituents, structural elements, sub-components and components as
structural complexity levels. The focus of the approach lies on the prediction of the
strength of structural joints as general weak point in sandwich constructions. It therefore
addresses analyses up until sub-component level, while the investigations on constituent
and structural element level are characterized by sufficient level of detail to enable the
representation of the complicated failure behavior in sandwich panel joints. In the present work, various sandwich materials and configurations were investigated in experimental and numerical studies covering all three considered structural complexity levels.
The performed studies were synthesized into the proposed approach.
On constituent level, the core was of primary interest since its mechanics often govern
failure initiation of sandwich structures. In this context, a detailed meso-scale honeycomb core model, which enables accurate representation of all core damage mechanisms, was established. In order to provide a computationally less expensive alternative,
a 3D-continuum core model was additionally implemented. The material parameters of
both core models were calibrated using macroscopic experimental results based on
standardized sandwich tests. In addition to the core, the face sheets and typical structural adhesives were investigated on constituent level. For the face sheets, it was established that the sandwich panel bonding process leads to considerable degradation of the
tensile face sheet modulus and strength. The obtained test results were implemented in
a suitable fabric composite material model. The adhesives were investigated in tension
© Springer-Verlag GmbH Germany, part of Springer Nature 2020
R. Seemann, A Virtual Testing Approach for Honeycomb Sandwich Panel
Joints in Aircraft Interior, Produktentwicklung und Konstruktionstechnik 16,
https://doi.org/10.1007/978-3-662-60276-8_9
The determination of the mechanical properties by means of physical testing is a major
cost driver in the development process of lightweight products. The implementation of
virtual tests based on FE-simulations can be a significant contributor to reducing the development cost. However, composite sandwich structures are characterized by a complicated failure behavior, making reliable predictions via FE-simulations challenging. The
present work addresses this problem by establishing a virtual testing approach for sandwich structures. The approach is based on the building block approach for the development of aircraft composite structures. Its structure therefore reflects the common classification in constituents, structural elements, sub-components and components as
structural complexity levels. The focus of the approach lies on the prediction of the
strength of structural joints as general weak point in sandwich constructions. It therefore
addresses analyses up until sub-component level, while the investigations on constituent
and structural element level are characterized by sufficient level of detail to enable the
representation of the complicated failure behavior in sandwich panel joints. In the present work, various sandwich materials and configurations were investigated in experimental and numerical studies covering all three considered structural complexity levels.
The performed studies were synthesized into the proposed approach.
On constituent level, the core was of primary interest since its mechanics often govern
failure initiation of sandwich structures. In this context, a detailed meso-scale honeycomb core model, which enables accurate representation of all core damage mechanisms, was established. In order to provide a computationally less expensive alternative,
a 3D-continuum core model was additionally implemented. The material parameters of
both core models were calibrated using macroscopic experimental results based on
standardized sandwich tests. In addition to the core, the face sheets and typical structural adhesives were investigated on constituent level. For the face sheets, it was established that the sandwich panel bonding process leads to considerable degradation of the
tensile face sheet modulus and strength. The obtained test results were implemented in
a suitable fabric composite material model. The adhesives were investigated in tension
© Springer-Verlag GmbH Germany, part of Springer Nature 2020
R. Seemann, A Virtual Testing Approach for Honeycomb Sandwich Panel
Joints in Aircraft Interior, Produktentwicklung und Konstruktionstechnik 16,
https://doi.org/10.1007/978-3-662-60276-8_9