2.4 Virtual testing
23
foam sandwich panel joints. They implemented a 3D-continuum model, while benchmarking different approaches for failure modeling. Heimbs and Pein [Hei09] developed
simplified 3D continuum models of inserts and panel edge joints, while including spotweld elements for an implementation in a global non-linear model of aircraft interior
components. Furthermore, they derived one of the first detailed models of a honeycomb
sandwich insert, where the hexagon core cells are modeled accurately. Additional studies on such detailed meso-models for honeycomb sandwich inserts include the work of
Bianchi et al. [Bia11], who investigated post and co-fab bonding procedures for honeycomb sandwich inserts with the help of linear FE-models. Roy et al. [Roy14] derived the
orthotropic material properties of Nomex honeycomb cell walls by comparing experimental results of partially potted inserts with a detailed FE-model of the joint. Silmane
et al. [Sli17] studied the sensitivity of the actual potting shape of aluminum honeycomb
inserts with respect to the position of the insert within the hexagon grid. Other examples
of detailed honeycomb joint models include the analysis of the thermal coupling of sandwich inserts used in satellites [Bou14] as well as an investigation of the potting shrinkage
during insert manufacturing [Cou15].
In the reviewed literature, computational models of sandwich panel joints were applied
for preliminary design studies or to gain better understanding of the governing damage
mechanisms. Applications where the models were intended to partially replace structural experiments by means of virtual testing are not evident.
2.4 Virtual testing
The term virtual testing originates from the aerospace industry where certification requirements demand extensive physical tests, which contribute to a large share of the
development cost. Hence, this industry is particularly pushing towards partially replacing
tests with virtual simulation models in order to reduce costs [Oke14]. This environment
requires high confidence in the simulation results. Therefore, virtual testing goes beyond
the mere application of simulation models. According to Cox et al. [Cox08] a virtual test
must be a system of hierarchical models, engineering tests, and specialized laboratory
experiments, supported by the application of information science, model-based statistical analysis, and decision theory. Wood [Woo12] summarized different sources and described virtual tests as capability to provide predictions for the physical behavior of structures, specifically the structural strength as well as progressive damage up to localized
and eventually catastrophic failure, while emphasis is put on the combination of testing
and simulation on all levels of the testing pyramid. Ostergaard et al. [Ost11] characterized virtual testing as concept with several attributes, which is to be understood as simulation using advanced non-linear finite element analysis. They also underlined the fact
23
foam sandwich panel joints. They implemented a 3D-continuum model, while benchmarking different approaches for failure modeling. Heimbs and Pein [Hei09] developed
simplified 3D continuum models of inserts and panel edge joints, while including spotweld elements for an implementation in a global non-linear model of aircraft interior
components. Furthermore, they derived one of the first detailed models of a honeycomb
sandwich insert, where the hexagon core cells are modeled accurately. Additional studies on such detailed meso-models for honeycomb sandwich inserts include the work of
Bianchi et al. [Bia11], who investigated post and co-fab bonding procedures for honeycomb sandwich inserts with the help of linear FE-models. Roy et al. [Roy14] derived the
orthotropic material properties of Nomex honeycomb cell walls by comparing experimental results of partially potted inserts with a detailed FE-model of the joint. Silmane
et al. [Sli17] studied the sensitivity of the actual potting shape of aluminum honeycomb
inserts with respect to the position of the insert within the hexagon grid. Other examples
of detailed honeycomb joint models include the analysis of the thermal coupling of sandwich inserts used in satellites [Bou14] as well as an investigation of the potting shrinkage
during insert manufacturing [Cou15].
In the reviewed literature, computational models of sandwich panel joints were applied
for preliminary design studies or to gain better understanding of the governing damage
mechanisms. Applications where the models were intended to partially replace structural experiments by means of virtual testing are not evident.
2.4 Virtual testing
The term virtual testing originates from the aerospace industry where certification requirements demand extensive physical tests, which contribute to a large share of the
development cost. Hence, this industry is particularly pushing towards partially replacing
tests with virtual simulation models in order to reduce costs [Oke14]. This environment
requires high confidence in the simulation results. Therefore, virtual testing goes beyond
the mere application of simulation models. According to Cox et al. [Cox08] a virtual test
must be a system of hierarchical models, engineering tests, and specialized laboratory
experiments, supported by the application of information science, model-based statistical analysis, and decision theory. Wood [Woo12] summarized different sources and described virtual tests as capability to provide predictions for the physical behavior of structures, specifically the structural strength as well as progressive damage up to localized
and eventually catastrophic failure, while emphasis is put on the combination of testing
and simulation on all levels of the testing pyramid. Ostergaard et al. [Ost11] characterized virtual testing as concept with several attributes, which is to be understood as simulation using advanced non-linear finite element analysis. They also underlined the fact