N&R Engineering provided structural and dynamic analyses support to NASA for the Integrated Vehicle Ground Vibration Test (IVGVT) project of the Ares-I launch vehicle. The Ares-I vehicle was to be the next generation launch vehicle under development for NASA. The IVGVT was intended to simulate launch and flight conditions for multiple vehicle configurations for separate stages of the Ares-I flight. Special Test Equipment to enact lateral and axial constraints for the IVGVT was designed to support the test configuration.
Simplified Finite Element (FE) one-dimensional beam models of the Ares-I vehicle were initially created with simplified mass and inertial properties along the length of the vehicle. The dynamic modal characteristics of these models were analyzed using forced and random vibration response. The specialized test equipment (STE) such as the aft support system and lateral constraints (modeled as one-dimensional springs) used to support the Ares-I vehicle during the IVGVT was modeled and integrated with the Ares-I vehicle beam models. The dynamic modal response of this test system was analyzed and compared to the system modes of the Ares-I vehicle beam models using cross-orthogonality techniques. Further work focused on incorporating detailed first and upper stage finite element models to the simulated Ares-I beam models to obtain further accurate modal response of the Ares-I vehicle and its IVGVT.
- Simplified finite element Ares-I vehicle beam and detailed hybrid models and the IVGVT STE
- Dynamic modal analysis of the Ares-I vehicle and the configured IVGVT models