Engineering topics
Publications and source records attributed to Masri, S. F..
On-line pulse control for vibration suppression in a flexible spacecraft was evaluated. A continuous beam vs. a truss was modeled. A linear finite element model was used to determine the truss characteristics. Control issues outlined are ED pulse actuator development, pseudo pulse algorithm development, and large nonlinear simulation problems.
A simple yet effective method is presented for the on-line vibration control of nonlinear distributed parameter systems, with constant or time-varying properties, responding to a wide class of dynamic environments. The control procedure uses pulse generators located at selected positions throughout a given system. The degree of system oscillation near each controller determines the controller's activation time and pulse amplitude. The direct method of Liapunov is used to establish that the response of the controlled nonlinear system is Lagrange stable. Analytical and experimental studies of a wing-like plate demonstrate the feasibility, reliability, and robustness of the proposed vibration-suppression method.
The following topics are covered in view graph form: (1) pulse control strategy; (2) stability analysis and digital simulations; (3) digital/analog and analog/digital conversions, and analog simulation; and (4) experimental studies.
Steady state motion equations of multiple unit impact damper attached to periodically excited primary system, developing solution for mathematical model
Steady state motion of sinusoidally excited primary system with impact damper solved analytically by piecewise linear technique
Steady state motion of multiple unit impact damper attached to sinusoidally excited primary system, determining asymptotically stable regions
Electric analog and mechanical model used to investigate single particle impact dampers
Extended theory of cumulative damage in fatigue when stress amplitude varies from cycle to cycle throughout life of structure
Periodic symmetric two-impacts-per-cycle motion of impact damper solved, determining asymptotically stable regions
Stability of two-impacts-per-cycle motion of impact damper