in this paper the control algorithm for controlled civil structures subjected to earthquake excitation is thoroughly investigated. the objective of this work is the control of structures by means of the pole placement algorithm, in order to improve their response against earthquake actions. successful application of the algorithm requires judicious placement of the closed-loop eigenvalues from ...

according to non-existence of accurate inspection tools on various steps of design and construction of buildings in the past, also due to any change in function of some structures and finally of seismic activities of residential regions of the country, vulnerability assessment of existing structures is necessary. evaluation of vulnerability of the structures is classified in two categories, qua...

in the process of structural analysis we often come to structures that can be analyzed with simpler methods than the standard approaches. for these structures, known as regular structures, the matrices involved are in canonical forms and their eigen-solution can be performed in a simple manner. however, by adding or removing some elements or nodes, such methods cannot be utilized. here, an effi...

‎    The Narumi-Katayama index is the first topological index defined by the product of some graph theoretical quantities. Let G be a simple graph. Narumi-Katayama index of G is defined as the product of the degrees of the vertices of G. In this paper, we define the Narumi-Katayama polynomial of G. Next, we investigate some properties of this polynomial for graphs and then, we obtain ...

This study based on free vibration analysis and study the behavior of framed structure under different frequency of vibration using ANSYS software and shaking table. A small scale uni-axial shaking table was prepared in laboratory, which can produce lower to moderate vibration, regarding frequency and velocity. Moment resisting framed structures constructed with connecting beam and column eleme...

carbonate materials are mostly found in tropical areas, where exploiting gas and oil resources are of high concern. their unique behavior under shear loading first was recognised during oil resources investigations in the persian gulf. off-shore structures have been placed on carbonate soils which are highly crushable.during storms cyclic loading imposes on the bases of structures lied down on ...

the study of flight vehicle structures reveals the importance of obtaining the most suitable accuracy compatible with construction. for this purpose, several experiments were conducted at the agard institute. in this paper the results of one such experiment performed on a sample airplane wing are presented. aircraft structural engineers use several methods to model these structures. specifing h...

the existence of some geometrically imperfect members, like initial curvature in a double layer space structures with hundreds or thousands of members is almost inevitable. these imperfections give rise to loss of load bearing capacity of double layer space structures. to evaluate the effect of initial member imperfection on load bearing capacity of double layer space structures and their failu...

Due to low stiffness of braces after yielding, the structures with buckling-restrained braces (BRBs) experience high residual drifts during an earthquake, which can be intensified by aftershocks and causes considerable damages to structures. Also, due to poor distribution of stiffness, this problem is exacerbated for irregular structures. Recently, the yielding brace system (YBS) has been intro...