pushover analysis is a simplified nonlinear analysis technique that can be used to estimate the dynamic demands imposed on a structure under earthquake excitations. one of the first steps taken in this approximate solution is to assess the maximum roof displacement, known as target displacement, using the base shear versus roof displacement diagram. that could be done by the so-called dynamic p...

progressive collapse is defined as the spread of an initial failure from element to element, eventually resulting in the collapse of an entire structure or a disproportionately large part of it. the current progressive collapse analyses and design methods in guidelines and codes focus on the alternate load path method. this method is suitable especially in the case of blast-induced progressive ...

The complex response characterizing elastomeric isolation bearings is reproduced by employing a novel uniaxial hysteretic model that has been recently formulated and successfully implemented in OpenSees. Such OpenSees material offers several advantages with respect to differential models typically available commercial software products for structural analysis, such as 3D-BASIS CSi programs. Fir...

We present an extension of the rigorous coupled-wave analysis technique to analyze second-harmonic generation (SHG) in periodic optical nanostructures in the undepleted-pump approximation. We apply this method to analyze SHG in two example nanostructures for which we predict enhanced nonlinearity due to transverse near-field localization of the fundamental optical field in the nonlinear materia...

An extremum principle is presented covering problems in solid mechanics equilibrium analysis for piecewise linear softening materials. Problems formulated according to this principle are expressed in a mixed “stress and deformation” form. The mechanics interpretation is limited according to linear deformation kinematics. More specialized models, such as an exfremumprinciple in mixed form for li...

This paper presents a novel interface element for the geometric and material nonlinear analysis of unreinforced brick-masonry structures. In the proposed modelling approach, the blocks are modelled using 3D continuum solid elements, while the mortar and brick-mortar interfaces are modelled by means of the 2D nonlinear interface element. This enables the representation of any 3D arrangement for ...

We exploit theoretically a new class of magneto-controlled nonlinear optical material based on ferrofluids in which ferromagnetic nanoparticles are coated with a nonmagnetic metallic nonlinear shell. Such an optical material can have anisotropic nonlinear optical properties and a giant enhancement of nonlinearity, as well as an attractive figure of

We detected the second-order nonlinear response from single isolated spheres comprised from a centrosymmetric material but covered by a layer of a material with strong second-order nonlinear properties and isolated from an ensemble by the optical trapping technique. We show that when large size parameter spheres are used, the measured second-harmonic efficiency deviates strongly from the predic...