Analysis of a single cross-section

The task is to carry out a quick cross-sectional analysis of a specific cross-sectional design. Specifically, in this example, we want to set values to the locations of spar webs and get the torsional and bending stiffness (\(GJ\), \(EI_{yy}\), \(EI_{zz}\)).

Running

Example location: examples/anl_cs_airfoil_box

ivabs analyze main.yml

Model

Cross-section.

This is a basic airfoil cross-section with a box spar, a front and a back components. Some basic parameters are listed below.

Cross-section parameters

Name	Value
Airfoil	SC1095
Coordinate origin	Trailing edge
Chord length	1.0 \(\mathrm{ft}\)
Pitch angle	0.0

The front edge of the front shear web of the box spar is located at 82% of the chord length from the trailing edge and the back edge of the back shear web is located at 58% of the chord length from the trailing edge.

The laminates of the box spar, the front and the back components are made of a the same lamina with a thickness of 0.0053 \(\mathrm{in}\) and the following property: \(E_{1}\) \(=2.8224 \times 10^9\) \(\mathrm{lbf/ft^2}\), \(E_{2}\) \(=192.96 \times 10^6\) \(\mathrm{lbf/ft^2}\), \(G_{12}\) \(=131.04 \times 10^6\) \(\mathrm{lbf/ft^2}\), \(\nu_{12}\) \(=0.348\). The layup of the box spar is \([-45/0/45/90]\). The layups of the front and the back components are \([0]\).

The front component is filled with a foam material with the following properties: \(E\) \(=1.92 \times 10^6\) \(\mathrm{lbf/ft^2}\), \(\nu\) \(=0.3\). The back component is filled with a honeycomb material with the following properties: \(E_1=E_2\) \(=144 \times 10^3\) \(\mathrm{lbf/ft^2}\), \(E_{3}\) \(=288 \times 10^3\) \(\mathrm{lbf/ft^2}\), \(G_{12}\) \(=144 \times 10^3\) \(\mathrm{lbf/ft^2}\), \(G_{13}\) \(=504 \times 10^3\) \(\mathrm{lbf/ft^2}\), \(G_{23}\) \(=835 \times 10^3\) \(\mathrm{lbf/ft^2}\), \(\nu_{12}\) \(=0.3\), \(\nu_{13}=\nu_{23}\) \(=0.01\).

The non-structural mass is modeled as a circular disk near the leading edge. The center of the non-structural mass is located at 96% of the chord length from the trailing edge and the radius is 0.5% of the chord length. The density of the non-structural mass is \(22\) \(\mathrm{slug/ft^3}\).

The design of the cross-section is based on a template airfoil_simple.xml.tmp.

Results

Analysis results can be found in the file main.out.

Results

Quantity	Value
\(GJ\)	\(2724.5607954\) \(\mathrm{lbf \cdot ft^2}\)
\(EI_{yy}\)	\(4077.8502077\) \(\mathrm{lbf \cdot ft^2}\)
\(EI_{zz}\)	\(247012.57502\) \(\mathrm{lbf \cdot ft^2}\)

Input files

main.yml

Main input file.

airfoil_simple.xml.tmp

Cross-sectional design template.

SC1095.dat

Airfoil data.

material_database_us_ft.xml

Material database.