Plastic hinge properties play a crucial role in predicting the nonlinear response of structural elements. The plastic hinge region of reinforced concrete normal beams has been previously studied experimentally and analytically. The main objective of this research is to evaluate the behavior of the plastic hinge region of reinforced concrete deep beams and its comparison with normal beams through finite element simulation. To do so, ten beams contain six deep beams, and four normal beams, under concentrated and uniformly distributed loading, are investigated. Lengths in the plastic hinge region involving curvature localization, rebar yielding, and concrete crushing zones are studied. The results indicate that the curvature localization zone is not suitable for the prediction of plastic hinge length in reinforced concrete deep beams. Based on the results it can be stated that in simply supported normal beams the concrete crushing zone is focused on the middle span, but in simply supported deep beams by creating a compression strut between loading place and support, the concrete crushing zone spreads along the compression trajectory. The rebar yielding zone of simply supported beams increases as the loading type is changed from the concentrated load at the middle to the uniformly distributed load.

Facilities built in areas affected by earthquake activity, such as tunnels, which have always been an integral part of human life, must withstand both dynamic and static loading. It has led to the need for practical studies on the effects of earthquakes on underground structures and the factors affecting their destruction. For this purpose, in this research, at first different patterns of tunnel’s excavation were investigated and by using Plaxis 2D software and based on Tabas earthquake in Iran, sensitivity ANALYSIS on geotechnical parameters of the soil surrounding tunnel such as cohesion, friction angle, unit weight and modulus of elasticity was carried out, and the parameters whose changes have the greatest and least effects on the bending moment changes on the tunnel lining are introduced. The results show that tunnel excavation patterns significantly affect the bending moment, axial forces, displacements, and surface settlement of the tunnel. Often, by dividing tunnel excavation area to small parts, the values of bending moment, axial forces, displacements, and surface settlement of the tunnel decreases in static ANALYSIS. Also, outputs of sensitivity ANALYSIS on geotechnical parameters of the soil surrounding tunnel showed that modulus of elasticity of the soil surrounding tunnel has the most effect and cohesion changes have the least effect on bending moment induced on tunnel lining..

In this paper, recommended spiral passive micromixer was designed and simulated. spiral design has the potential to create and strengthen the centrifugal force and the secondary flow. A series of simulations were carried out to evaluate the effects of channel width, channel depth, the gap between loops, and flowrate on the micromixer performance. These features impact the contact area of the two fluids and ultimately lead to an increment in the quality of the mixture. In this study, for the flow rate of 25 μl/min and molecular diffusion coefficient of 1×10-10 m2/s, mixing efficiency of more than 90% is achieved after 30 (approximately one-third of the total channel length). Finally, the optimized design fabricated using proposed 3D printing method.

In this research, in order to investigate the effect of the piezoelectric patch which is used as a sensor or actuator in rotating flexible structures such as a helicopter blade, the free vibrations of the rotating rectangular sheet with and without the piezoelectric patch have been presented. First-order shear deformation theory is considered for plate displacement and piezoelectric field. Considering the effect of Coriolis acceleration, centrifugal acceleration and centrifugal in-plane forces, the equations of motion are derived from Hamilton's principle and the electromechanical couple equation is obtained from Maxwell's equation. For piezoelectric, two electrical conditions, open circuit and closed circuit, which are used in sensors and actuators, respectively, have been considered. The equations are discretized with the help of the NUMERICAL method of generalized differential squares and the matrices of inertia mass, eccentricity, Coriolis and stiffness matrix are obtained. Natural frequency values for beam and rotating plate have been compared in Abaqus software. Also, the values obtained from the NUMERICAL solution in MATLAB have been verified with articles and ABAQUS, which have high accuracy. The effect of parameters such as hub radius, rotation speed, sheet thickness, aspect ratio, piezoelectric patch thickness and applied voltage on the natural frequency of the system has also been investigated.

In this study, stability of geosynthetic reinforced soil retaining walls investigated using PLAXIS code that is based on finite element method. The effects of axial stiffness, length and vertical space between geosynthetic layers, internal friction angle of soil wall and cohesion of foundation on deformations of wall and maximum axial force of geosynthetic have been investigated. Results of analyses indicated that horizontal displacements and settlements of wall reduce with increase in axial stiffness, length and decrease of vertical space between reinforcement layers but there is a critical value for axial stiffness, length and number of geosynthetic layers which increase more than this certain value has not significant effect on reduction of settlements and horizontal displacements of wall. Also vertical and horizontal deformations of wall reduce with increase in internal friction angle of soil wall and cohesion of foundation but effect of these two factors on reduction of deformations for values more than a critical value are almost constant.

In this work, A 3-dimensional model is developed to investigate fluid flow in a magneto-hydrodynamic micropump. The equations are NUMERICALly solved using the finite volume method and the SIMPLE algorithm. This study analyzes the performance of the magnetohydrodynamic micropump. For this purpose, a magnetohydrodynamic micropump built in 2000, is simulated. The micropump has a channel with 20mm length, width of 800mm, height of 380mm and an electrode with 4mm length. The applied magnetic flux density was 13mT and the electric current was different for various solution (10-140 mA). The results show that the intensity of the magnetic field, the electric current and the geometry has an effect on the magnetohyrodynamic micropump performance. By increasing the amount of magnetic flux and electric current the average velocity increases. decreasing the channel length would increase the mean flow velocity. by increasing the channel depth, the mean flow velocity initially increases and then decreases, while at a depth of approximately 700-800mm the maximum averaged velocity will be resulted. The velocity increases by Increasing the channel width to 1500mm, however the velocity remained unchanged for larger values.

Purpose: The flourishing of political parties and currents is one of the signs of the degree of development in societies. In contemporary Iran and since the formation of the constitutional movement, political currents have gone through many ups and downs and it can be said that political currents in Iran after the Islamic Revolution have not yet reached the stage of institutionalization and stability. A characteristic feature of political currents in Iran is the divergence and division among political currents in recent decades, and this can be one of the reasons for the instability and cross-sectional and seasonal activity of political parties in Iran. Therefore, the necessity of leading research seeks to answer the question of how factors and divergence among political currents in Iran after the victory of the Islamic Revolution can be analyzed? And what are the scenarios for the advancement of political currents in Iran?Method: To answer this question, the method of causal-layer ANALYSIS, which is one of the qualitative methods in futures research, has been used.Findings: The research findings indicate that this divergence is due to a wide range of reasons from the level of causal systems (from the institutionalization of power to the formation of parties as elitist initiatives), worldview and discourse (from charismatic political authority to culture). Subsidiary-follower politics to myth-metaphor (Iranian individualism to belief in a strong state-weak society) can be analyzed.Conclusions: Three scenarios for the future of Iranian political currents can be considered: integration of currents as the security valve of the political system, the collapse of political currents in the traditional form, integration and consolidation in new social movements (virtualized parties).

Given any structure, we seek to find the solution of mechanical problem as precisely and efficiently as possible. Within this condition, the BEM is robust and promising development, standing out in the ANALYSIS of cases with occurrence of large stress gradients, as in problems of fracture mechanics. Moreover, in BEM the modeling of infinite means is performed naturally, without the use of approximations. For methods involving domain integration, such as FEM, this is not possible, as models with high number of elements are usually adopted and their ends are considered flexible supports. This paper deals with the development of NUMERICAL models based on the BEM for mechanical ANALYSIS of stiffened domains. In the modeling of hardeners, immersed in a medium defined by the BEM, we tried to use both the FEM, already present in the literature, and the BEM 1D, being a new formulation. The objective was to perform the coupling of BEM with FEM and BEM 1D for elements of any degree of approximation, evaluating both isotropic and anisotropic medium. In addition, a complementary objective was to verify the effects of the adoption of different discretization and approximation degrees on the stiffeners. However, the coupling with the BEM 1D leaded to more stable results and better approximations. It was observed that the FEM results were instable for many results, mainly in the quadratic approximations. When the approximation degree rises, the methods tend to converge to equivalent results, becoming very close in fourth degree approximation. Lastly, it was observed stress concentration in the stiffeners ends. In these regions, the discretization and the approximation degree have large influence to the NUMERICAL response.