Structural Dynamics

Overview

AeroTex has extensive experience in the area of Structural Dynamics working for both Aircraft Primes and Research Organisations.

We have extensive experience in building and analysing complex structural models, modal testing and model correlation.

Capabilities

Advanced Structural Analysis

• Normal modes.
• Forced response (Harmonic) analysis.
• Transient analysis – internal/external explosion modelling, crash sled design and analysis, modelling of embedded electromechnical systems (e.g. piezoelectric).
• Random vibration – analysis of air-carriage and satellite launch.
• Non-linear static and transient analysis.
• DMAP (NASTRAN) – user defined routines to extract or insert non-standard matrices in to analysis.

Vibration Testing

• Experience in ground vibration testing on a range of test articles from missiles through to aircraft.
• Experience in hammer (rap) testing to extract structural modes.
• Instrumentation – selection and optimisation of instrumentation types and locations.
• LMS TestLab – experience in using LMS TestLab for hammer, forced vibration and in the working environment.

Model Updating

• Analyse structural model responses under normal modes and enforced response.
• Use of displacements and  energies to identify key areas for model refinement.

Case Studies

Model Development & Correlation

AeroTex worked with an aircraft prime to develop a whole aircraft model of an airframe including engine installations and used this for correlation activities.

• More than 700,000 elements resolving the structure to 2cm and adapted to cover 3 aircraft variants.
• Correlation and model updating performed based on Ground Vibration Testing.
• Success of the model has led to it being adopted by the structures department and the model further developed.
• Model successfully correlated in terms of displacement and strain against static test.

Framework Vibration Reduction

A major UK company had encountered issues with vibration during testing. AeroTex was employed to reduce vibrations to an acceptable level.

• Trials and instrumentation plan including accelerometers and pressure transducers.
• Instrumentation and LMS data acquisition verification shakedown tests.
• Baseline tunnel tests.
• Develop vibration reductions schemes using replayed tunnel loading through shakers.
• Wind-on validation vibration reduction demonstration tests showed  significant vibration reduction.