Landing mats that can undergo a large amount of area deformation are now essential for the safe completion of landings in gymnastics. The objective of this study was to develop an analytical model of a landing mat that reproduces the key characteristics of the mat-ground force during impact with minimal simulation run time. A force plate and two high-speed video cameras were used to record the ...

Due to the complex nonlinearity of magnetorheological (MR) behavior, the modeling of MR dampers is a challenge. A simple and effective model of MR damper remains a work in progress. A novel model of MR damper is proposed with force-velocity hysteresis division method in this study. A typical hysteresis loop of MR damper can be simply divided into two novel curves with the division idea. One is ...

A transverse damping system is used in the Recycler at Fermilab to damp beam instabilities which arise from large beam intensities with electron cooling. Initial tests of electron cooling demonstrated beam loss due to transverse beam motion when the beam was cooled past the beam density threshold. The transverse damper system consists of two horizontal and two vertical pickups whose signals are...

Previously published work on applied impact damping typically relates to SDOF models or simple MDOF models such as the classical cantilever beam. Structural models often require an extremely large number of DOF with mode shapes that are generally very complex. Dynamics simulation of these typically becomes both complicated and time consuming. The nonlinear behavior of impact dampers further com...

In this paper, the development of a semiactive suspension control of quarter car model using fuzzy-based controller has been done. The quarter car model to be used here can be described as a nonlinear two degrees of freedom system which is subject to excitation from different road profile. The semi-active control is designed as the fuzzy control inferred by using two single input rule fuzzy mod...

-The performance of fuzzy logic (FLC) and PID controllers optimized by particle swarm optimization (PSO) for semi-active suspension system using magneto-rheological (MR) damper are investigated. MR damper is an intelligent damper filled with particle magnetic polarizable and suspended into a liquid form. The Bouc-Wen model of MR damper is used to determine the required damping force based on fo...

Most current seatbelt load limiter technologies could only offer three or fewer predetermined patterns of seatbelt restraint force. However, researches have shown that, to better realize adaptive protection to different occupants under different crash severities, a continuously and real-time adjustable load limiter may be one step further. This concept could be especially favorable to vulnerabl...

A new self-powered and sensing semi-active control system based on magnetorheological (MR) damper is presented. The system includes four key parts: a rack and pinion mechanism, a linear permanent magnet DC generator, a current adjustment MR damper, and a control circuit. Numerical simulations for seismic protection of elevated bridges equipped with this system excited by two historical earthqua...

The effectiveness of Metallic dampers for seismic response reduction of structures is quite well known in the earthquake engineering community. However, little attention has been paid to evaluating the influence of the number and placement of this type of dampers on the dynamic response. Using genetic algorithms as an optimization technique will allow for the simultaneous number and design of a...

This paper investigates the use of inerters for vibration suppression of a multistorey building structure. The inerter was proposed as a two-terminal replacement for the mass element, with the property that the applied force is proportional to the relative acceleration across its terminals. It completes the force-current mechanical-electrical network analogy, providing the mechanical equivalent...