Information on suspended sediment variation in times of flood is important in management of water resources, particularly management of basins, and in investigation of the causes of erosion. The relationship between discharge and suspended sediment concentration during floods is not similar and homogeneous for different reasons such as precipitation variety, discharge rate and sources of sediment and production of hysteretic loops. In this study, the instantaneous values of suspended load were simulated using genetic programming and regression methods. By comparing the two models, Genetic programming model was selected as the better one with the mean square error and determination coefficient of 0.8 and 0.5, respectively. Then based on this model, loops of suspended hysteretic load were drawn for the six events recorded in the period of 1387-1383. This resulted in 4 linear and 2 clockwise hysteretic loops for the river suspended sediment. Identifying various hysteretic loops is effective in determination of relative contributions of processes to production and transfer of sediment including amount and intensity of precipitation, flow rate and previous moisture conditions of watershed. The results showed that the clockwise hysteretic loops occurred usually in high precipitation and discharge, and linear hysteretic loops in spring because of low intensity precipitation.

Based on ASTM E1823 standard, fatigue phenomenon is the process of permanent, progressive and localized structural change which occurs to a material point subjected to strains and stresses of variable amplitudes which produce cracks which lead to total failure after a certain number of cycles.
During an earthquake fatigue failure can occur at loads much lower than tensile or yield strengths of material. Therefore material behavior under cyclic loading is an important design criterion.
Fatigue data are obtained from the experiments and are shown in S-N curves which represent stress or strain amplitude versus number of cycles. All fatigue ranges can be included generally in three categories. Ultra Low Cycle Fatigue (ULCF), Low Cycle Fatigue (LCF), and High Cycle Fatigue (HCF). HCF is recognized with low strain amplitude and high frequency, and LCF is a material deterioration which is described as high plastic strain amplitude and low frequency. ULCF involves a few cycles (less than 20) of large plastic strains. ULCF is of great importance for structural and earthquake engineers, because fatigue failure in structural members occurs generally in less than 10 cycles during a seismic event. Fatigue fracture in moment connections, or gusset plates and brace members are examples for ULCF or ductile fracture.
Fatigue life is expressed as the total number of stress cycles required for a fatigue crack to initiate and grow large enough to produce fatigue failure. Currently, two major methods are available for fatigue life prediction of structures. One type is based on material fatigue life curves (e.g., S–N curves or ε–N curves) and a damage accumulation rule. The other is based on fracture mechanics and crack growth analysis.
The Manson–Coffin law is the most widely used procedure to predict material failure under LCF and ULCF. But last researches showed that Manson–Coffin relation overestimates fatigue life in ULCF domain.
Miner’s rule is one of the most widely used cumulative damage models for failures caused by fatigue.
The rainflow method is a method for counting fatigue cycles from a time history. The counting of each load cycle and the relative damage produced must be done with extreme accuracy and care. Rainflow counting has been shown to be most effective. The rainflow method allows the application of Miner's rule in order to assess the fatigue life of a structure.
In this paper low cycle fatigue performance of restrained buckling braced frames with diagonal, V-shaped and chevron configurations are investigated. Last researches and experimental tests results of BRBs usually show very stable hysteresis behavior with an excellent low cycle fatigue life.
In this study For modeling the low cycle fatigue phenomenon, the “fatigue material” model in OpenSees is used. The fatigue material uses a modified rainflow cycle counting algorithm to accumulate damage in a material using Miner’s Rule. Once the Fatigue material model reaches a damage level of 1.0, the force (or stress) of the material becomes zero and the material is destructed completely.
By obtaining the hysteretic loops and also the cumulative damage charts of diagonal, V-shaped and chevron buckling restrained braced frames, the hysteretic behavior and fatigue life of them are evaluated. Buckling restrained braces in three configurations of concentrically braced frames, exhibited stable hysteretic behavior up to failure. Considering area of the hysteretic loops and low cycle fatigue life, V-shaped buckling restrained braced frame showed better low cycle fatigue performance.

Tuned mass damper is a common tool in passive control, which is used in many structures. However, with all the proper features, its most important functional limitation is the weakness against broad band excitation. Various methods have been proposed to overcome this problem, among which using hysteretic damping of materials with nonlinear behavior is known effective. Among materials with nonlinear behavior, shape memory alloys have good features and large hysteresis loops. Hence, in this paper, using nonlinear stiffness and hysteretic damping of a shape memory alloy spring, linear stiffness and viscous damping of a common tuned mass damper are replaced. Then, the modified damper has been used to control responses of a single degree of freedom structure under harmonic loadings and the effect of the loading amplitude on the control of the structural responses was determined. Subsequently, the damper has been used to control seismic responses of single degree of freedom structures to compare its performance under broad band seismic loadings with the performance of conventional tuned mass dampers. Results of the analyses show that the characteristics of shape memory alloys can adequately control the impact of the loading amplitude on the performance of nonlinear mass dampers. Also, the presence of hysteretic damping can significantly improve control of seismic responses of single degree degrees of freedom structures compared to conventional tuned mass dampers, provided that dynamic properties of the nonlinear mass damper take their optimal values.

Rapid assessment of structural safety and performance following the occurrence of important events such as moderate to severe earthquakes is so significant and vital and reveals the need for developing online and pseudo-online health monitoring methods. Online monitoring methods can be implemented without the need for in-situ testing and expert staff to analyze the recorded data. In other words, these methods provide comprehensive information on the condition of the structure only by using the vibration data recorded by embedded sensors as well as the preset health monitoring algorithms. On the other hand, most civil structures exhibit a nonlinear response after severe incidents like earthquakes. In many cases, this nonlinear hysteretic behavior is along with stiffness deterioration, strength degradation, pinching effect, permanent plastic deformation, or a combination of them. Therefore, considering a comprehensive definition of damage that takes into account the nonlinear behavior of structures according to their type is one of the most important steps in the process of structural identification and evaluation. Various methods have been introduced in the literature for online estimation of states and parameters of nonlinear structures. However, the challenging part in most of these methods is the determination of parameters noise covariance matrix which becomes particularly important due to the increasing number of structural floors, thus increasing the number of unknown parameters. In this study, an effective method for online jointly estimation of state and parameters of nonlinear hysteretic structures with consideration of degradation and pinching phenomena is proposed. Simultaneous estimation of states and parameters is conducted using a combination of Unscented Kalman Filter as an effective estimator and Robbins-Monroe stochastic approximation technique as the parameters noise covariance matrix regulator. The abovementioned method was applied to two one-story and one three-story shear buildings and the results of the identification process were presented with emphasis on the effects of measurement noise, modeling error, and use of the Monte-Carlo random simulation method. Simulation results demonstrated the accuracy and efficiency of the proposed method in online jointly estimation applications as well as the desirable capability to track hysteretic curves of each structural floor.

Records of near-field earthquakes due to the closely location of the source wave propagation has special properties That their behavior makes them more different than other records. The most important characteristic of these earthquakes, is a pulse amplitude at the beginning of the record Which has a high energy content. The use of Hysteresis dampers is an effective way to attract a large proportion of this energy. In this paper, according to nonlinear dynamic analysis and using PERFORM 3D software, by adding Buckling Restrained Braces (BRB ) with different configurations to the 4 and 8 story 2D Concrete frames with medium ductility, The seismic performance of Moment-Resisting Frames and retrofitted by Buckling Restrained Braces under seven near-field earthquakes have been measured and compared. According to Nonlinear Dynamic Analysis, The level of story displacement, interstory drift and dissipated energy by buckling restrained braces have been Provided. The results indicate the Buckling Restrained Braces have good performance in absorbing energy and the reduction of story displacement.

Real accelerations and subsequent wall diaplecements appear as the main damage Factors in liquid storage tanks. Base-isolation systems, as the most appropriate earthquake engineering options in passive control, can be used to reduce these factors and following destruction of these special structures. In this paper, the dynamic behavior of base-isolated rectangular tanks is studied under different ground motions in which, two tanks (one broad and one slender) with fixed-base and LRB base-isolatiors including different stiffnesses, i.e. stiff and flexible, are considered. In the developed model, finite elements and boundary elements for the shell and liquid domains and nonlinear hysteretic elements for isolation system are respectively employed to perform the analysis of the flexible tank in frequency and time domains. Further, the effect of base-isolators on the seismic response of the whole system including natural frequency, liquid sloshing height, base shear and moment and dynamic pressure on the tank shell, under harmonic and real earthquake has been inspected.

The main issue of the present research is the doubt about the recording and consequently the correction and explanation of a bit of one of Sa’di's Ghazal which has been recorded in most of the available printed versions as follows: بازآ و حلقه بر در رندان شوق زن The acceptance of the recording of "Rendan" in this bit by various proofreaders has caused the commentators to provide various, contradictory and unrelated descriptions based on the structure of the text. In this research, using various evidences, it has been proved that the correct recording of the word mentioned in this verse is "Zendan" and not "Rendan". based on a cognitive poetic approach, it is clear that the present bit is illustrated on the basis of an image schema and the conceptual metaphor of "passion is prison." This conceptual metaphor is The result of the c Sa’di's tendency to spatialize abstract concepts.