Structural Dynamics

This section lists some of our capabilities under the general heading of “Structural Dynamics”. Our structural dynamic expertise includes:

  • Component finite element model (FEM) reductions to dynamic math model (DMM):
    • Fixed-interface (Hurty/Craig-Bampton)
    • Free-interface (Rubin, Rubin-MacNeal)
    • Mixed-interface (Majed-Henkel: ASD developed/default in NASTRAN)
    • Modal
    • Interface stiffness/mass loaded(Benfield-Hruda)
  • Component DMM output transformation matrix (OTM) generation:
    • Mode-acceleration method
  • Component-modal synthesis (CMS):
    • Analytical integration of component DMMs/OTMs
    • Includes CMS of component damping matrices
  • FEM and DMM checks:
    • Multi-level stiffness, damping, and mass balance checks, mass properties, 1G checks, effective modal mass, frequencies, and rigid body OTM checks
  • Transient dynamic analysis
  • Nonlinear transient dynamic analysis
    • Includes the impact of friction, deadbands, snubbers, bumpers, multi-linear springs (straps, foam, ...), contact/re-contact, isolation, nonlinear dampers, ...
  • Frequency-domain analysis
  • Random vibration analysis
  • Shock-response spectra analysis
  • Base-drive analysis:
    • Time-domain
    • Frequency-domain
    • Random vibration analysis
  • Multi-body, large angle, analyses:
    • Mechanisms
    • Flexible body simulations
  • Rotordynamic analyses:
    • Lateral analysis including gyroscopic, gravity, shaft bow, hydrodynamic bearings, bearing damping/stiffness, fluid-structure interaction, ...
    • Torsional analysis including transient start-up, shut-down, short-circuit, mal-synchronization, ...
  • Aeroelastic analysis:
    • Static aeroelastic response
    • Flutter
  • Monte Carlo and structural parametric variational analyses

Case Histories

  • Development of component dynamic math models/OTMs and component-modal synthesis of the EADS Integrated Cargo Carrier for multiple Space Shuttle mission verification loads cycles.
  • Transient and random vibration base-drive assessment of the Oceaneering Space Systems ESPAD compliant mount launch lock bolts for Space Shuttle mission ULF1.
  • Development of component dynamic math models/OTMs and component-modal synthesis of Spacehab’s Logistic Single Module for multiple Space Shuttle mission verification loads cycles.
  • Independent Verification & Validation of EADS Integrated Cargo Carrier dynamic math models and OTMs for multiple Space Shuttle mission verification load cycles.
  • Independent Verification & Validation of Lockheed-Martin’s Space Lab Pallet dynamic math models and OTMs for Space Shuttle Mission 1J/A .
  • Residual flexibility mixed-boundary reduction dynamic math model and OTM development for the EADS Integrated Cargo Carrier for multiple Space Shuttle missions.
  • Residual flexibility mixed-boundary reduction dynamic math model and OTM development for the Spacehab Logistic Single and Double Modules for multiple Space Shuttle missions.
  • Transient dynamic assessment of the International Space Station S0 truss (Boeing).
  • Rotordynamic analysis of the GE LM-5K engine (~ 40 design iterations).
  • Rotordynamic analysis of the GE LM-6K engine.
  • Random vibration analysis of AeroAstro STPSat-1.
  • Monte Carlo coupled loads analysis to assess the impact of the modal uncertainties in two European International Space Station science payloads manifested on Space Shuttle mission ULF-1 (Boeing).
  • Multibody analysis to derive Temporomandibular Joint (TMJ) trajectories to aid Presswood Engineering’s artificial TMJ designs.
  • Investigation into the root-cause of the random vibration high frequency spike issue with the Oceaneering Space Systems ONE EVA Vibration Test System.
  • Random vibration analysis in support of Design Net’s Rideshare Adapter structural qualification testing for RazakSat-Falcon 1 Mission.