Sharif Digital Repository

The structural instability of an array of cantilevers, each of which interacts with two neighbouring beams through electrostatic and van der Waals forces, is studied. Distributed and lumped parameter modelling of the array result in a set of coupled nonlinear boundary value problems and a set of coupled nonlinear equations, respectively. These coupled nonlinear systems are solved numerically for different numbers of beams in the array to obtain the pull-in parameters. The pull-in parameters converge to constant values with an increase in the number of beams in the array. These constants, which are important in the design of cantilever arrays, are compared for the distributed and lumped... 

Cantilever arrays with nearest-neighbor interactions are considered to obtain the pull-in parameters. The interactions between the neighboring beams are a combination of the Casimir force and the electrostatic force with the first-order fringing field correction. A set of coupled nonlinear boundary value problems and a set of coupled nonlinear equations arise in the distributed and lumped parameter modeling of the array, respectively. The models are simulated numerically to obtain the pull-in parameters of the arrays with different number of beams. The pull-in parameters of large arrays converge to constant values, which are independent of the number of beams in the array. The constants... 

This paper presents a bi-directional closed-form analytical solution, in the framework of nonlinear soft composites mechanics, for top-down hyperelastic characterization of brain white matter tissue components, based on the directional homogenized responses of the tissue in the axial and transverse directions. The white matter is considered as a transversely isotropic neo-Hookean composite made of unidirectional distribution of axonal fibers within the extracellular matrix. First, two homogenization formulations are derived for the homogenized axial and transverse shear moduli of the tissue, based on definition of the strain energy density function. Next, the rule of mixtures and...