On the basis of the Euler-Bernoulli hypothesis, nonlinear static and dynamic responses of a viscoelastic microbeam under two kinds of electric forces [a purely direct current （DC） and a combined current composed of ...On the basis of the Euler-Bernoulli hypothesis, nonlinear static and dynamic responses of a viscoelastic microbeam under two kinds of electric forces [a purely direct current （DC） and a combined current composed of a DC and an alternating current] are studied. By using Taylor series expansion, a governing equation of nonlinear integro-differential type is derived, and numerical analyses are performed. When a purely DC is applied, there exist an instantaneous pull-in voltage and a durable pull-in voltage of which the physical meanings are also given, whereas under an applied combined current, the effect of the element relaxation coefficient on the dynamic pull-in phenomenon is observed where the largest Lyapunov exponent is taken as a criterion for the dynamic pull-in instability of viscoelastic microbeams.展开更多
Based on Timoshenko-Mindlin kinematic hypotheses and Hamilton's principle,a dynamic non-linear theory for general laminated circular cylindrical shells with transverse shear deformation is developed.A multi-mode s...Based on Timoshenko-Mindlin kinematic hypotheses and Hamilton's principle,a dynamic non-linear theory for general laminated circular cylindrical shells with transverse shear deformation is developed.A multi-mode solution for periodic in- plane loads is formulated for the non-linear dynamic stability of an anti-symmetric angle-ply cylinder with its ends elastically restrained against rotation.The resulted equations in terms of time function are solved by the incremental harmonic balance method.展开更多
文摘On the basis of the Euler-Bernoulli hypothesis, nonlinear static and dynamic responses of a viscoelastic microbeam under two kinds of electric forces [a purely direct current （DC） and a combined current composed of a DC and an alternating current] are studied. By using Taylor series expansion, a governing equation of nonlinear integro-differential type is derived, and numerical analyses are performed. When a purely DC is applied, there exist an instantaneous pull-in voltage and a durable pull-in voltage of which the physical meanings are also given, whereas under an applied combined current, the effect of the element relaxation coefficient on the dynamic pull-in phenomenon is observed where the largest Lyapunov exponent is taken as a criterion for the dynamic pull-in instability of viscoelastic microbeams.
文摘Based on Timoshenko-Mindlin kinematic hypotheses and Hamilton's principle,a dynamic non-linear theory for general laminated circular cylindrical shells with transverse shear deformation is developed.A multi-mode solution for periodic in- plane loads is formulated for the non-linear dynamic stability of an anti-symmetric angle-ply cylinder with its ends elastically restrained against rotation.The resulted equations in terms of time function are solved by the incremental harmonic balance method.
