SDA Projects

Structural Dynamics and Acoustics

The following describes some of the contracts we have had in Structural Dynamics and Acoustics:

  • Blast and Shock Analysis for Vulnerability Codes: In this contract we are developing new techniques for characterizing Blast waves and shocks striking a vehicle
  • Pressure Vibration Temperature Controller (PVTC): In this contract we developed the control system for introducing shock, acoustic blast waves and vibration to the missile structure as well as “steady-state” airflow, pressure and temperature levels for the US Navy Pacific Missile Testing facility
  • Vulnerability Code Software Development: In this contract for Wright Patterson Air Force Base, we wrote graphical editor and data translator to and from the Fastgen Vulnerability code and the NASTRAN structural dynamics code
  • VC100: The VC100 is a commercial product described as a real-time PC-based analyzer and signal generator. In addition to continuous vibration signal output, shock output can be generated with various shapes and the resulting acceleration measurements analyzed using the Shock Response Spectra technique
  • Wake/Structure Interaction Interior Noise: In this NASA Lewis contract we developed software to predict unsteady aerodynamics, sound propagation and interior fuselage noise from the interaction of next generation prop fan wakes with the downstream wing and fuselage structure

In the area of dynamic testing GCAS has three retail test systems products:

  • CCAS: In a joint effort with one of the world’s leading accelerometer manufacturer’s ENDEVCO, GCAS has developed software for controlling up to 1080 amplifiers simultaneously for use in large complex mechanical tests. This system controls the banks of amplifiers through an IEEE 488 bus. In addition to maintaining the set up information on the amplifier gains, phase and other relevant data, CCAS provides real-time monitoring of the RMS signal level on each channel during testing
  • VC100: The VC100 is a full function real-time analyzer and signal generator. Transient or continuous waveforms can be generated of any spectral shape and output as an excitation function. Transient or continuous data can be captured and analyzed in either the frequency or time domain using a high speed array processor. A 1024 point FFTs can be calculated in 18 milliseconds. Transfer functions are calculated using cross spectral analysis methods to determine the Transfer Function, Frequency Response Function and Coherence of two simultaneous signal measurements. Signal Source information is then obtained from such cross spectral calculations by evaluating the phase correlations of the signals
  • PVTC: The Programmable Vibration and Temperature Controller (PVTC) is a multi-purpose, Thermo/Dynamic Control System for reliability testing. The system can simultaneously control up to ten (10) independent Vibration /Acoustic loops. Up to three (3) channels can be averaged for control in either open or closed loop. The output is a continuous Gaussian random signal mixed with any user select pre-stored shock waveform of up to 1.6 seconds in duration. Temperature is controlled using two full PID loops for heating and cooling over the range from -132 to 752 degrees fahrenheit. Nineteen (19) TTL outputs and eight (8) TTL inputs are also monitored and controlled