In this paper a simple tool for seismic design of steel structures for a selected ductility level is presented. For this purpose, a consistent set of earthquakes is selected and sorted based on the maximum acceleration of ground surface. The selected records are applied as the base motion to a single-degree-of-freedom system with strain hardening and the maximum response acceleration is determi...

A simple procedure to formulate efficient and stable hybrid/mixed finite elements is developed, for applications in macroas well as micromechanics. In this method, the strain and displacement field are independently assumed. Instead of using two-field variational principles to enforce both equilibrium and compatibility conditions in a variational sense, the independently assumed element strains...

In this paper, we present a new technique for 3D shape morphing using strain fields. Strain is an important geometric quantity used in mechanics to describe the deformation extent of objects. We use it to analyze and control deformation in morphing. Using the position vector field, the strain field between source and target shapes can be obtain. This strain field is then interpolated between ze...

Strain localization is closely associated with the stress-strain behavior of an interphase system subject to quasi-static direct interface shear, especially after peak state is reached. This behavior is important because it is closely related to deformations experienced by geotechnical composite structures. This paper presents a study using two dimensional DEM simulations on the strain localiza...

The nonlocal nonlinear buckling of a double layer graphene sheet (DLGS) covered by zinc oxide (ZnO) piezoelectric layers is investigated in this study. The surrounding circumstances of the system are considered as a Pasternak foundation including spring constants and a shear layer. Graphene sheets are subjected to longitudinal magnetic field and biaxial forces. On the other hand, the ZnO piezoe...

We report here the first experimental measurements of nonlinear rheological material properties of hagfish slime, a hydrated biopolymer/biofiber network, and develop a microstructural constitutive model to explain the observed nonlinear viscoelastic behavior. The linear elastic modulus of the network is observed to be G′ ≈ 0.02 Pa for timescales 0.1 s ≤ t ≤ 10 s, making it one of the softest el...

Strong motion records made by vertical arrays allow estimation of nonlinear soil behavior in layers at different depths. As an example, records obtained during the 1995 Hyogo-ken Nanbu earthquake at Port-Island, SGK, and TKS sites are used to estimate the stress-strain dependencies of soils. For different layers, different types of nonlinear stress-strain curves are determined, showing the best...

The onset of nonlinear responses in near hard sphere suspensions is characterized as a function of oscillatory frequency and strain amplitude. At low frequencies where the viscous behavior dominates, the onset of nonlinearities is driven by increases in rate of strain. At high deformation frequency, where suspension mechanics is dominated by an elastic response, the nonlinear responses occur wh...