A new concept for obtaining large-amplitude rotary displacements from small linear displacements generated by induced-strain active material stacks is considered. The concept utilizes the theory of twist-warping coupling in thin-wall open tubes. A large-displacement induced-strain rotary actuator, LARIS Mk 2, was built and tested under static and dynamic conditions. A rotary displacement of 6 w...

In this paper, we analyze the effect on the ball-bat model of corking the bat, and investigate the relationship between the sweet spot and different materials. First and foremost, we develop a simple but effective theoretical model to give a rough estimate for the sweet spot of the bat. Second, we give a simplified abstract form of bat which facilitates the description and modeling study. Last ...

The phenomenon of parametric resonance is explained and investigated both analytically and with the help of a computer simulation. Parametric excitation is studied for the example of the rotary oscillations of a simple linear system— mechanical torsion spring pendulum excited by periodic variations of its moment of inertia. Conditions and characteristics of parametric resonance and regeneration...

Here, the dynamic stability characteristics of simply supported laminated composite skew plates subjected to a periodic in-plane load are investigated using the finite element approach. The formulation includes the effects of transverse shear deformation, in-plane and rotary inertia. The boundaries of the instability regions are obtained using the Bolotin’s method and are represented in the non...

The objective of this study is to present a brief survey on the geometrically nonlinear free vibrations of the Bernoulli-Euler, the Rayleigh, shear, and the Timoshenko beams with simple end conditions using the Homotopy Analysis Method HAM . Expressions for the natural frequencies, the transverse deflection, postbuckling load-deflection relation to, and critical buckling load are presented. The...

In this paper, the flow-induced vibration and flutter instability of cantilever carbon nanotubes conveying fluid and modeled as a thin-walled Timoshenko beam are investigated. Analytically nonlocal theory, transverse shear and rotary inertia effects are incorporated in this study. The governing equations and the boundary conditions are derived through Hamilton's principle. Numerical analysis is...