In this paper, the effect of the crack on dynamic behavior of cracked micro-beam in the presence of DC and AC loads are investigated. By applying the residual axial stress and fringing field stress, a nonlinear analytical model of cracked micro-beam is presented and crack is modeled by a massless rotational spring. The governing equation of the system is solved using Galerkin procedure and shoo...

The assessment of seismic performance of existing structures is becoming an important problem in earthquake engineering. Some important ructures are considerably old and, therefore, their strengths and ductilities are less than strength and ductility demands because of changes in codes and design methodologies. Such structures must be strengthened to resist future earthquakes. First, a structur...

In order to increase the accuracy of evaluating seismic response of structures, it is critical to conduct dynamic analyses based upon precise nonlinear models being as consistent as possible with the real conditions of corresponding structures. The concentrated plasticity model including one elastic element and two nonlinear spring elements at both ends has been considered within the research c...

Nonlinear problems are more challenging and almost complex to be solved. A recently developed Homotopy Perturbation Method (HPM) is introduced. This method is used to represent the system as a less complicated (almost linear) model. To verify the effectiveness, HPM based model is compared with the nonlinear dynamic in both open and closed loop PI controlled. The error indices are approximation ...

Evolving models have found applications in many real world systems. In this paper, potentials of the Evolving Linear Models (ELMs) in tracking control design for nonlinear variable structure systems are introduced. At first, an ELM is introduced as a dynamic single input, single output (SISO) linear model whose parameters as well as dynamic orders of input and output signals can change through ...

Endurance time (ET) method is a relatively new performance-based earthquake method for structural evaluation and design. In this method, the structure is subjected to a gradually intensifying accelorogram(s) and its performance is assessed based on the maximum time duration that it can meet the specified performance objectives. Using moment-resisting and braced frames which are rehabilitated by...