2.3 Computational analysis
17
Feldhusen et al. [Fel09] developed a mechanical joining technology for joining sandwich
structures based on established design methodology. However, their solutions were only
implemented for large scale aluminum-foam sandwich structures for civil engineering
applications.
2.3 Computational analysis
One of the foundations for computational analysis of sandwich structures is the first order shear deformation theory (FSDT) based on Mindlin & Reissner. The FSDT enables two
dimensional models to simulate the transverse shear deformation of the core, which can
contribute considerably to the total panel deformation due to the low shear modulus of
typical sandwich cores. This is illustrated in Figure 15.
Figure 15 Sandwich panel deformation due to bending
The FSDT has been adapted for sandwich structures making assumptions such as, low inplane normal stiffness and infinite transverse stiffness of the core as well as thin face
sheets if compared to the core height. The result is the so called sandwich theory which
was established by Allen [All69] and Plantema [Pla66]. It was later complemented by
high-order theories, which enable non-linear displacement fields of the core due to its
soft nature. These high-order displacement theories (HSDT) are for instance required to
model localized effects such as point loads. Based on these theories, there is an abundance of computational models described in the literature. Noor et al. [Noo96] distinguished between four categories; detailed models, 3D-continuum models, 2Dshell/plate models and simplified models. Simplified models are often derived from
sandwich theory and generally enable to simulate specific isolated effects, such as bending deflection, wrinkling or buckling, often by means of analytical equations [Zen97].
There are also numerous simplified models for the estimation of the equivalent homogenized elastic and ‘plastic’ honeycomb core properties based on the cell geometry and
material. Such models were proposed by Meraghni et al. [Mer99], Hohe and Becker
[Hoh02] as well as Gibson and Ashby [Gib10]. These simplified models are important
tools for preliminary design studies of sandwich plates. The three remaining categories
are, today, commonly realized using the numerical Finite Element Method (FEM). 2D
shell and plate models represent the most basic group of FE-models. They can be implemented as single layer equivalent or discrete multilayer models based on the FSDT or
17
Feldhusen et al. [Fel09] developed a mechanical joining technology for joining sandwich
structures based on established design methodology. However, their solutions were only
implemented for large scale aluminum-foam sandwich structures for civil engineering
applications.
2.3 Computational analysis
One of the foundations for computational analysis of sandwich structures is the first order shear deformation theory (FSDT) based on Mindlin & Reissner. The FSDT enables two
dimensional models to simulate the transverse shear deformation of the core, which can
contribute considerably to the total panel deformation due to the low shear modulus of
typical sandwich cores. This is illustrated in Figure 15.
Figure 15 Sandwich panel deformation due to bending
The FSDT has been adapted for sandwich structures making assumptions such as, low inplane normal stiffness and infinite transverse stiffness of the core as well as thin face
sheets if compared to the core height. The result is the so called sandwich theory which
was established by Allen [All69] and Plantema [Pla66]. It was later complemented by
high-order theories, which enable non-linear displacement fields of the core due to its
soft nature. These high-order displacement theories (HSDT) are for instance required to
model localized effects such as point loads. Based on these theories, there is an abundance of computational models described in the literature. Noor et al. [Noo96] distinguished between four categories; detailed models, 3D-continuum models, 2Dshell/plate models and simplified models. Simplified models are often derived from
sandwich theory and generally enable to simulate specific isolated effects, such as bending deflection, wrinkling or buckling, often by means of analytical equations [Zen97].
There are also numerous simplified models for the estimation of the equivalent homogenized elastic and ‘plastic’ honeycomb core properties based on the cell geometry and
material. Such models were proposed by Meraghni et al. [Mer99], Hohe and Becker
[Hoh02] as well as Gibson and Ashby [Gib10]. These simplified models are important
tools for preliminary design studies of sandwich plates. The three remaining categories
are, today, commonly realized using the numerical Finite Element Method (FEM). 2D
shell and plate models represent the most basic group of FE-models. They can be implemented as single layer equivalent or discrete multilayer models based on the FSDT or