Romesh C. Batra

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We study the influence of von Karman nonlinearity, van der Waals force, and a athermal stresses on pull-in instability and small vibrations of electrostatically actuated mi-croplates. We use the Galerkin method to develop a tractable reduced-order model for elec-trostatically actuated clamped rectangular microplates in the presence of van der Waals(More)
We analyze electrostatic deformations of rectangular, annular circular, solid circular, and elliptic micro-electromechanical systems (MEMS) by modeling them as elastic membranes. The nonlinear Poisson equation governing their deformations is solved numerically by the meshless local Petrov–Galerkin (MLPG) method. A local symmetric augmented weak formulation(More)
We describe the development of modules for teaching a senior level course, Mechanical Behavior of Materials, that incorporate the results of state of the art simulation techniques. The modules are Web-Java based and make extensive use of materials available through the Internet. The most important characteristic of these modules is that they teach the(More)
A robust nonlinear observer, utilizing the sliding mode concept, is developed for the dynamic positioning of ships. The observer provides the estimates of linear velocities of the ship and bias from the slowly varying environmental loads. It also filters out wave frequency motion to avoid wear of actuators and excessive fuel consumption. Especially, the(More)
An analytical solution is presented for three-dimensional thermomechanical deformations of a simply supported functionally graded (FG) rectangular plate subjected to time-dependent thermal loads on its top and/or bottom surfaces. Material properties are taken to be analytical functions of the thickness coordinate. The uncoupled quasi-static linear(More)
Three-dimensional deformations of a multilayered, linear elastic, anisotropic rectangular plate subjected to arbitrary boundary conditions at its edges are analyzed by the generalized Eshelby-Stroh formalism. The rectangular laminate consists of anisotropic and homogeneous laminae of arbitrary thicknesses. Perfect bonding is assumed between the adjoining(More)
This work describes a complete framework for generation of compact analog circuit macromodels which significantly reduce the model complexity while still capturing the dominant linear and nonlinear response of the circuit. The technique is applicable to a broad class of circuits that exhibit weakly nonlinear behavior such as mixers, RF power amplifiers and(More)