# Analysis of Aircraft Fittings

Fittings for aircraft panels are described.

Fittings involving aircraft panels, the bulkhead, angle, tee, skin and lateral panels
are meshed using quadrilateral elements. The fittings are meshed using tetrahedral
elements. The fasteners are defined using RBE2 and
CBUSH elements.

The above fitting is analyzed for tensile and compressive loads, in two different load steps.

The details of loading and the boundary conditions for the model are:

The analysis is performed with different analysis types.

## Model Files

Before you begin, copy the file(s) used in this example to
your working directory.

## Linear Static Analysis

The element forces for the CBUSH elements are then reviewed in the
Tension and Compression cases.

## Nonlinear Analysis with Pre-loaded Fasteners

Nonlinear material property is defined using TABLED1 for aluminum
and a pre-tension of 6000 lbs. is applied to the fasteners using the
DEFORM card.

## Large Displacement Nonlinear Analysis with Pre-loaded Fasteners

Large displacement nonlinear analysis can be activated with PARAM,
LGDISP in OptiStruct. Figure 5 shows the results from a Nonlinear Large
Displacement Analysis.