3. Modeling A#

3.1. Characteristics of modeling A#

_images/100000000000060200000295E490978F1801EEDF.png

Figure 3.1-1: Problem geometry mesh

In this modeling, the complete structure is meshed using 3D solid elements.

The flatness constraint is expressed as follows. Be it,

  • point A \(X=0\), \(Y=h/2\), \(Z=0\): \(\mathit{DX}=\mathit{DY}=0\), \(\mathit{DZ}\ne 0\);

  • point B \(X=0\), \(Y=h/2\), \(Z=b\): \(\mathit{DX}=\mathit{DY}=0\), \(\mathit{DZ}\ne 0\);

  • the C point \(X=0\), \(Y=h\), \(Z=b/2\): \(\mathit{DX}\ne \mathit{DY}\ne 0\), \(\mathit{DZ}=0\)

By neglecting second-order terms in displacements, the flatness constraint results in a linear relationship between the \(\mathit{DX}=0\) displacements of the points \(A\), \(B\), \(C\) and \(P\), any point on the face:

\(∣\begin{array}{cccc}{\mathit{DX}}_{P}& {Y}_{P}& {Z}_{P}& 1\\ {\mathit{DX}}_{A}& h/2& 0& 1\\ {\mathit{DX}}_{B}& h/2& b& 1\\ {\mathit{DX}}_{C}& h& b/2& 1\end{array}∣=0\)

The condition is then written for \({\mathit{DX}}_{A}=0\):

\({\mathit{DX}}_{P}={\mathit{DX}}_{C}\times (\frac{2{Y}_{P}}{h-1})\)

In \(X=L\), the flatness condition is obtained in the same way but for any \({\mathit{DX}}_{A}\). The relationship is then written:

\({\mathit{DX}}_{P}={\mathit{DX}}_{C}\times (\frac{2{Y}_{P}}{h-1})+2\times (1-\frac{{Y}_{P}}{h})\times {\mathit{DX}}_{A}\)

3.2. Characteristics of the mesh#

Number of knots: 1077

Number of meshes and types: 160 HEXA20

3.3. Tested sizes and results#

Mode

Reference Value

Reference Type

Tolerance (%)

1

\(115.7\)

“ANALYTIQUE”

\(1.0\)

2

\(442.2\)

“ANALYTIQUE”

\(1.0\)

3

\(648.6\)

“ANALYTIQUE”

\(1.0\)

4

\(931.6\)

“ANALYTIQUE”

\(1.0\)

5

\(1534.0\)

“ANALYTIQUE”

\(1.0\)