A general framework is presented for analyzing and optimizing stability increases due to mistuning. The framework given is model independent and is based primarily on symmetry arguments. Diicult practical issues are transformed to tractable mathematical questions. It is shown that mistuning analysis reduces to a block circular matrix eigenvalue/vector problem which can be solved eeciently even ...

Introduction High frequency lateral tape motion (LTM) is a problem in tape technology that limits track density in a tape drive. To reduce high frequency LTM, it is important to identify all sources of lateral tape motion. The most important sources of high frequency LTM are edge contact between tape and tape drive components, non-repeatable roller axial run-out, air induced flutter and tape te...

The synthesis and experimental validation of an active utter suppression controller for the Active Flexible Wing wind-tunnel model is presented. The design is accomplished with traditional root locus and Nyquist methods using interactive computer graphics tools and extensive simulation-based analysis. The design approach uses a fundamental understanding of the utter mechanism to formulate a sim...

tients with stmchmlly normal hearts following noncontact mapping guided ablation of idiopathic left or right ventricular tachycardia. A signiiicant inverse correlation was found between activation times and ARIs during sinus (I= -0.68&0.23), paced (I= -0.82&0.12), and ventricular ectopic (I= -0.66&0.43) rhythms using the alternative NCM method. However, no significant relationship between activ...

The problem of the determination of the subcritical aeroelastic response and flutter instability of nonlinear two-dimensional lifting surfaces in an incompressible flow-field via Volterra series approach is addressed. The related aeroelastic governing equations are based upon the inclusion of structural nonlinearities, of the linear unsteady aerodynamics and consideration of an arbitrary time-d...

Macroscopic, microscopic, and mesoscopic lumped-parameter models of shape memory alloy wires subjected to axial loads and new flutter prediction methods of a steady and a non-steady aeroelastic system will be presented with some comparison to previous studies.

The combined influences of unsteady aerodynamics, dynamics, viscoelasticity and piezoelectricity are studied to determine their interaction and influence on sensing and structural control. Critical parameters are identified and numerical simulations are used to evaluate their sensitivities to system responses and to predict flutter conditions and control.

If simple arbitrary modes of the form $ are used as coordmates in a win2 flutter cakdation, the equations are ill-conditioned and wm.mt be solvea satisfactorily on a simulator. This ill-conditioning can be avoided by trxmsfoming the flutter matrix so as to m&me the inertw couplings between like modes to zero. This tran.%%mation is &scribed with nmm.uxiL examples, aad some observo.t~ons are nxdo...

Aerodynamic forces on bridges are commonly separated into static, self-excited, and buffeting force components. By delving into the relationships among force descriptors for static, self-excited, and buffeting components, novel perspectives are developed to unveil the subtle underlying complexities in modeling aerodynamic forces. Formulations for airfoil sections and those based on quasisteady ...