When microbubbles are excited by two frequency signals, a nonlinear response signal may occur at the difference frequency. As these two frequencies are made close, this nonlinear response will reside at lowfrequency region. We have derived a theory for the weak short-pulse response based on a two-frequency approximation, which provides the pressure and the bandwidth dependence properties of the...

This paper employs one-dimensional numerical ground response analysis models to investigate seismic response of shallow cohesive and non-cohesive soil deposits on vertical propagation of horizontal shear waves. Soil response is modelled by traditional equivalent-linear (EL) frequency-domain analysis using DEEPSOIL software and nonlinear (NL) time-domain analysis using OPENSEES software. The ana...

In this study, the effect of earthquake frequency content and noise effects on damage detection has been investigated. For this purpose, the damage was defined as nonlinear behavior of beams and columns, and several ground motion records were scaled so that some elements yield under the applied excitation. Then the acceleration response data of each floor obtained using the nonlinear dynamic an...

The application of NPID, or nonlinear PID, control is demonstrated experimentally on an optical storage playback device (CD drive) for automotive applications. The nonlinear design aims at improved shock suppression under equal noise response. This is done by introducing variable controller gains. Namely under large levels of low-frequency vibration, the controller gains are increased as to imp...

Soil sites have a profound effect on ground motion during earthquakes due to their low wave speeds, layered structure, and nonlinear constitutive relationship. Measurements of nonlinear soil response under natural conditions are critical to understanding soil behavior during earthquakes. Currently, quantitative measurements of nonlinear soil response are derived from laboratory experiments on s...

The neurons in layer II of the medial entorhinal cortex are part of the grid cell network involved in the representation of space. Many of these neurons are likely to be stellate cells with specific oscillatory and firing properties important for their function. A fundamental understanding of the nonlinear basis of these oscillatory properties is critical for the development of theories of grid...

In general, joints are assumed without clearance in the dynamic analysis of multi-body echanical systems. When joint clearance is considered, the mechanism obtains two uncontrollable degrees of freedom and hence the dynamic response considerably changes. The joints’ clearances are the main sources of vibrations and noise due to the impact of the coupling parts in the joints. Therefore, the syst...

A study on the evaluating equivalent damping and response modification factors of frames equipped by Pall Friction Dampers is presented. To do so, buildings with various stories were considered. Nonlinear and linear dynamic time history analysis has been performed to evaluate equivalent damping for Pall Friction Dampers. Ground motions with various frequency characteristics scaled with Iranian ...