response modification factor (r factor) is one of the seismic design parameters to be considered in evaluating the performance of buildings during strong motions. this paper has tried to evaluate the response modification factor of concrete coupled shear wall structures with various length/depth ratios of spandrel beams. the effect of diagonal reinforcement of spandrel beam was also evaluated o...

Autonomous unmanned aerial vehicles (UAVs) that can execute aggressive (i.e., high-speed and high-acceleration) maneuvers have attracted significant attention in the past few years. This article focuses on accurate tracking of quadcopter trajectories. We propose a novel control law for position yaw angle their derivatives up to fourth order, specifically velocity, acceleration, jerk, snap along...

Efficiency of numerical methods is an important problem in dynamic nonlinear analyses. It is possible to use of numerical methods such as beta-Newmark in order to investigate the structural response behavior of the dynamic systems under random sea wave loads but because of necessity to analysis the offshore systems for extensive time to fatigue study it is important to use of simple stable meth...

Hexagrid structural system is an innovated system with structural behavior which is similar to a tubular system. In this paper, a numerical study is conducted to estimate the seismic performance of horizontal hexagrid concerning the combined horizontal and vertical hexagrid, tubular and diagrid structural systems. First 30 and 50 story buildings are modeled using ETABS, then pushover and nonlin...

A main challenge for performance-based seismic engineering is to develop simple, practical and precise methods for analyzing designed buildings and assessing existing structures to satisfy considerable performance objectives. Pushover analysis is a simplified nonlinear analysis technique that can be implemented for estimating the dynamic demands imposed on a structure under earthquake excitatio...

zipper braced frames are an innovative bracing system for steel structures. conventional inverted-v-braced frames exhibit a design problem arising from the unbalanced vertical force generated by the lower story braces when one of them buckles. this adverse effect can be mitigated by adding zipper columns or vertical members connecting the intersection points of the braces above the first floor....

In the seismic risk assessment of structures, two main random variables are involved, namely the vulnerability of the structure and the seismic action. The aim of the study presented here is to analyze the seismic behavior of the jacket-type offshore platforms as an expensive and vital structure. Furthermore, the influence of the incidence angle of the seismic action is also investigated by usi...

In this study a numerical calibration of the most widely accepted damage indices, for quantifying the extent of damage in reinforced concrete structures, is performed. In particular, the Park and Ang local damage index, its modified variant proposed by Kunnath, Reinhorn and Lobo; the Chung, Meyer and Shinozuka local damage index; along with the maximum and final softening damage indices propose...