Structural Analysis

With structural analysis we show that an aeronautical or space structure withstands its design loads with the required margins, and with the lowest possible weight. In fact, it is the work behind every certification file and every change to an aircraft in service, and it applies the principles of structural mechanics.

Structural analysis: from load to margin of safety

Everything starts from the load cases: manoeuvres, landings, gusts, emergency loads and thermal conditions. For each one we first derive the internal loads in the components, then compare them with the material allowables and finally calculate the margin of safety. As a result, a positive margin says the part holds, while one that is too high says we can make it lighter.

At Limit Load the structure must not suffer permanent deformation; at Ultimate Load, however, it must not fail. Stress recovery, that is extracting stresses from the model and checking them point by point, takes the most time and needs the most experience.

What we verify

• Metallic primary and secondary structures
• Joints: riveted and bolted joints, attachments and fittings
• Stability of panels and stringers (compression and shear buckling)
• Interior and furnishing components, such as crashworthy seats
• Ground support equipment and test rigs

Verifications ready for review

We deliver reports that whoever has to approve them can read easily: assumptions, load cases, models, results and margins, with every number traceable to its source. For this reason, your design office, and also the certification authority, can follow the structural analysis without redoing the calculation.

The analysis often starts from a model built with numerical simulation and ends with a qualification test. For example, on the AW09 programme we followed exactly this path.