Papers by Keyword: SDOF System

Abstract: With the increase in acts of terrorism, the effects of the explosion on structures has become highly topical. The aim of the paper is an analysis of various approaches to determine the response of blast loaded reinforced concrete pillar. Homemade ANFO (Ammonium nitrate + fuel oil) explosive will be a reference explosive. Such type of explosives is the most used one in terroristic attacks. The paper will be focused on the analysis of the blast wave, based on the experimental tests, and dynamic analysis of a structure under such load.

Abstract: Based on the energy-based design approach, variation of seismic dissipation energy with structural properties is investigated by using the SDOF model and the trilinear constitutive. The influence of structural ductility on hysteretic energy, damping energy, hysteretic energy ratio and damping energy ratio is investigated, and the evolution trend of hysteretic and damping energy spectra with ductility ratios and damping ratios is examined for structures subjected to the north south component of El Centro, the Imperial Valley, California earthquake of May 18, 1940.

Abstract: This work presents simplified models, in the form of single degree of freedom (SDOF)elasto-plastic systems, for the dynamic analysis of traditional reinforced concrete (RC) and fibre-reinforced concrete (FRC) circular plates under blast loads. Two cases have been examined inthis study: simply supported and resting on Winkler-type soil plates. Both cases intend toprovide a simplified tool for predicting the response respectively for specimens subjected toblast pressure wave inside shock-tube facilities and for slabs on ground under blast loads. Thesecond case also represents the loading conditions inside a new shock tube facility specificallyintended for the investigation of underground tunnel lining subjected to blast loads.

Abstract: From the perspective of fractal geometry, the irregularity and complexity of near-fault ground motions and seismic responses of single degree of freedom (SDOF) are analyzed. Based on the box-counting method, the fractal dimensions of 30 acceleration time series of near-fault ground motions from Taiwan Chi-Chi earthquake and California Northridge earthquake are calculated. It is indicated that the acceleration time series of ground motions present the statistical fractal property, and the influence of characteristics of near-fault ground motions on their box dimensions is remarkable. Moreover, the box dimensions of ground motions reflect their frequency property to a large extent, and can be regarded as alternative index to represent their frequency content. Finally, for the time histories of seismic dynamic responses of elastic and inelastic SDOF systems subjected to near-fault ground motions, their box dimensions are computed to examine the fractal property.