Although several studies have investigated the effect of degradation on the behavior of structures, investigations on collapse margin ratios are rare in the literature. In this study, the effect of strength and stiffness degradation on collapse capacity of steel moment frames is investigated. The aim is to determine margin of safety against collapse using a probabilistic approach. For this reas...

Application of impact energy absorption systems in different industries is of special significance. Thin-walled tubes, due to their lightness, high energy absorption capacity, long crushing length and the high ratio of energy absorption to weight, have found ever-increasing application as one of the most effective energy absorption systems. In this research, through  carrying out experimental t...

in this paper, an attempt has been made to introduce a new control strategy including plug-in hybrid electric vehicle (phev) and diesel engine generator to control the voltage and frequency of autonomous microgrids. the proposed control strategy has multiple advantages over the recent control methods in microgrids. the proposed method applies the primary and secondary frequency control strategy...

Voltage collapse and blackout can occur in an electric power system when load powers vary so that the system loses stability in a saddle node bifurcation. We propose new iterative and direct methods to compute load powers a t which bifurcation occurs and which are locally closest to the current operating load powers. The distance in load power parameter space to this locally closest bifurcation...

This paper solely discusses the voltage instability with the increment of load in a radial distribution system with Distribution Generation(DG) and compared to the system with Facts. The active and reactive power support from DG makes the system more reliable to voltage collapse. FACTS are also very good in reactive power compensator for the “sagging” voltages during the voltage collapse. The f...

Disproportionate collapse analysis aims to assure that frames, a common structural system of buildings, can survive unforeseen local events and a central modeling tool of such abnormal deterioration is the concept of column loss. This paper formulates an appropriate computational model on the basis of mathematical optimization, using the collapse load analysis problem of steel frames with pre-e...

The analysis of the bearing capacity of structures with a rigid-plastic behaviour can be achieved resorting to computational limit analysis. Recent techniques [3],[4] have allowed scientists and engineers to determine upper and lower bounds of the load factor under which the structure will collapse. Despite the attractiveness of these results, their application to practical examples is still ha...

in this study, the stability problem of a circular orthotropic cylindrical shell under the effect of anaxial compression varying with a power function of time is considered. at first, the modified donnell typedynamic stability and compatibility equations are obtained using love’s shell theory. applying the galerkinmethod and rayleigh-ritz variational techniques to these equations and taking the...

soil contamination significantly reduces environmental quality and affects human health. to investigate and assess the effects of land use on the concentrations of some heavy metals in surface soils of golestan province, 227 soil samples (0-60 cm) were collected from three types of land uses including agricultural lands, natural, and industrial areas. the total metals and metalloids (cr, se, as...