An energy-based approach has been used to investigate the seismic behavior of code-designed asymmetric-plan systems. The systems considered in this investigation had large eccentricities in both directions, were designed for bidirectional earthquake loading, and their responses were computed with both components of ground motion acting simultaneously. The presented results demonstrate that the ...

This research investigates the structural health monitoring of nonlinear structures after a major seismic event. It considers the identification of flag-shaped or pinched hysteretic behaviour in response to structures as a special, perhaps more general, case of a normal hysteretic curve without pinching. The method is based on the overall least squares solution and the asymptotic distribution t...

In assessments of the seismic adequacy of existing steel bridges, the anchorage of steel truss piers to their foundations often has insufficient strength to resist seismic demands. Many other non-ductile failure locations may also exist along the seismic load path that cannot provide adequate seismic performance. Although strengthening is an option, this approach may only transfer damage to ano...

The computational modeling of hysteretic dampers is a powerful tool for design, allowing us to predict and optimize damper performance. In this research, numerical model, based on Chaboche’s nonlinear kinematic hardening constitutive law, was implemented. parameters law were identified validated by inverse analysis, the macro-hysteretic response hexagonal honeycomb steel damper. model applied s...

Vibration damping in polycrystalline TbDy alloys was studied at cryogenic temperatures. Mechanical hysteretic losses were measured at various strains, frequencies, and loading configurations at 77 K. Some textured TbDy materials demonstrated 22.6% energy dissipation in mechanical measurements at low frequency ~0.01 Hz! and a mean logarithmic decrement of 0.23 at a higher frequency ~25 kHz!. Ult...

Comprehensive physical models can accurately quantify the dynamics of nonlinear and hysteretic systems but often require significant computational cost. This can reduce their effectiveness when performing sensitivity analysis, uncertainty analysis, parameter calibration or system design which typically requires multiple iterations of computationally expensive routines. This can also preclude th...

In this article, to study the effect of pulse-type near-fault earthquakes on the seismic demands of steel moment frames, 15-story 2D-frame was analyzed under the influence of 20 near-fields with forward directivity effect and 2 far-field records. The relationship between Effective Cyclic Energy, ECE and displacement demands, velocity and hysteretic curve of SDOF systems in two near- and far-fau...

Atomic scale dissipation is of great interest in nanomechanics and atomic manipulation. We present dissipation measurements with a linearized, ultra-small amplitude atomic force microscope which is capable of measuring dissipation at chosen, fixed separations. We show that the dynamic dissipation in the noncontact regime is of the order of a few 10-100 meV per cycle. This dissipation is likely ...

Arrays of aligned carbon nanotubes (CNTs) under compression are known to exhibit a dissipative hysteretic response similar to classical foams. Here, we control the microstructure of the arrays during synthesis using a variable supply of carbon source and catalyst. We control CNT alignment and density along the array height, creating bands of highand low-density regions. We study the dynamic res...