The dynamic response of an initially flat viscoelastic membrane is investigated. The viscoelastic model is described with fractional order derivatives. The membrane is subjected to surface transverse and inplane dynamic loads. The governing equations are three coupled second order nonlinear partial FDEs (fractional differential equations) of hyperbolic type in terms of the displacement componen...

The object of this paper is the evaluation of the seismic response of reinforced concrete frames designed according to the DDBD (direct displacement-based design) approach. The great part of research works about DDBD has been dedicated to planar frames, but recently also some proposals for 3D structures have been presented, in particular for wall structures. This paper will give a further contr...

A formula to estimate the yield displacement observed in the pushover analysis of coupled wall lateral force-resisting systems is presented. The estimate is based on the results of an analytical study of coupled walls ranging from 8 to 20 stories in height, with varied amounts of reinforcement in the reinforced concrete coupling beams and walls, subjected to first-mode pushover analysis. An exa...

Seismic design procedures in current building provisions are based on linear and nonlinear static approaches that use capacity-demand index relationships such as the relationship between the lateral strength and the maximum lateral displacement. Previous research on the development of these relationships is based on linear-elastic ground motion acceleration response spectra, whereas the current...

S U M M A R Y On November 8 1997 a M w 7.6 earthquake occurred in the Manyi region of northern Tibet, near the western end of the Kunlun Fault. Over 7 m of left-lateral slip occurred on a 200-kmlong fault. Here we use InSAR observations of post-seismic surface deformation following the Manyi earthquake to investigate possible causal mechanisms. Time-series of deformation are constructed from 26...

This paper presents an analytical investigation on the peak lateral displacement demands of “hybrid” precast concrete panelized shear wall structures under seismic loading. The hybrid wall structure investigated uses a combination of mild [i.e., Grade 400 (U.S. Grade 60)] steel bars and highstrength unbonded post-tensioning (PT) strands for lateral resistance across horizontal joints. The analy...

Energy calculations are generally made through an empirical application of the famihar Gutenberg-Richter energy-magnitude relationships. The precise physical significance of these relationships is somewhat uncertain. We make use here of the recent improvements in knowledge about the earthquake source to place energy measurements on a sounder physical basis. For a rumple trapezoidal far-field di...

The primary focus of a structural shake table system is the accurate reproduction of acceleration records for testing. However, many systems deliver variable and less than optimal performance, particularly when reproducing large near-field seismic events that require extreme table performance. Improved identification and control methods are developed for large hydraulic servo-actuated shake tab...

despite the current use of radiography for quantifying sagittal skeletal measurements, it is an unsuitable way for screening or epidemiologic purposes. although not fully approved, anthropometric measurements have been suggested as a substitute, and considering displacement of soft tissues, could possibly lead to more consistent results. the purpose of this study was to evaluate the reliability...

seismic inversion is a method that extracts acoustic impedance data from the seismic traces. sourcewavelets are band-limited, and thus seismic traces do not contain low and high frequency information.therefore, there is a serious problem when the deterministic seismic inversion is applied to real dataand the result of deterministic inversion is smooth. low frequency component is obtained from w...