1. Reference problem#

1.1. Geometry#

_images/1000000000000523000002386D0FC4CCF9683083.png

Figure 1.1-1: Problem geometry

_images/1000000000000182000002368E0686A7F2FBD1E2.png

Figure 1.1-2: Problem geometry

Height: \(h=0.2\text{m}\)

Width: \(b=0.1\text{m}\)

Length: \(L=2\text{m}\)

Section: \(A=b\times h=0.02\text{m}\)

Inertia: \(I=\frac{b\times {h}^{3}}{12}=1.66\times {10}^{-5}\text{m}\)

Section reduction coefficient \(k\text{'}=\frac{5}{6}\)

1.2. Material properties#

Young’s module

\(E=2.1\times {10}^{11}\mathit{Pa}\)

Poisson’s Ratio

\(\nu =0.3\)

Density

\(\rho =7800.0{\mathit{kg.m}}^{-3}\)

Sliding module

\(G=\frac{E}{2(1+\nu )}=8.076\times {10}^{10}\text{Pa}\)

1.3. Boundary conditions and loads#

Only the flexure in the \(\mathit{XY}\) plane and the extension along the \(X\) axis are allowed. Since the model is solid, the boundary conditions differ somewhat from those that would be imposed on a beam model.

Imposed displacement:

In \(X=0\), \(Y=h/2\)

\(\mathit{DX}=0\), \(\mathit{DY}=0\)

In \(X=L\), \(Y=h/2\)

\(\mathit{DY}=0\)

In \(Z=b/2\)

\(\mathit{DZ}=0\)

To the previous conditions, we add the flatness constraint of the sections in \(X=0\) and \(X=L\). This constraint can be expressed as follows. Let’s designate \({x}^{T}=(X,Y,Z)\) the coordinate vector and \({u}^{T}=(\mathit{DX},\mathit{DY},\mathit{DZ})\) the displacement vector; the position of a point is identified by the vector \(x{\text{'}}^{T}={x}^{T}+{u}^{T}=(X\text{'},Y\text{'},Z\text{'})\). Let \(A\), \(B\), and \(C\) be three non-aligned points in the section. Any point \(P\) is subject to the condition:

\(∣\begin{array}{cccc}X{\text{'}}_{P}& Y{\text{'}}_{P}& Z{\text{'}}_{P}& 1\\ X{\text{'}}_{A}& Y{\text{'}}_{A}& Z{\text{'}}_{A}& 1\\ X{\text{'}}_{B}& Y{\text{'}}_{B}& Z{\text{'}}_{B}& 1\\ X{\text{'}}_{C}& Y{\text{'}}_{C}& Z{\text{'}}_{C}& 1\end{array}∣=0\)