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.

One of the important issues to be considered in the design of earth dams is seepage. In general, all soils are more or less water to pass through and accept the intrusion Therefore, in most cases follow the flow of water into the embankment dams is inevitable. If you can not control and restrict the flow of water in dams cause problems and adverse effects that sometimes "destruction and failure of the dam will follow. In this study, a comprehensive review has been Numerical modeling of a two-dimensional percolation. After the the study has been presented dam and dam of Hamedan Abshineh been thoroughly studied. then, using the finite element method, two-dimensional and three-dimensional seepage analysis, about the dam was conducted and its results with the results of analyzes two-dimensional comparison, the sensitivity analysis carried out after the stage and perform two- and three-dimensional analysis of the impact of various parameters on the amount of leakage is discussed, at the end solutions to deal with this phenomenon in Hamedan Abshineh proposed dam Are. Due to the geometry of the sort of things can be very variable, and since the construction of three-dimensional model is very bulky and time consuming, so in this study, only one block parameters and specific (case study) used Are.All analyzes were carried out in this thesis Isothermal and interaction effects of heat stress on -transformation leak is ignored.

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.

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.

With the fast and inexpensive personal computers of today, Numerical Methods have become more popular in engineering science. More frequently, Numerical Methods used in continuum and discontinuum analysis are the finite element and finite difference Methods. On the other hand, slope stability analysis is usually performed by the limit equilibrium method. In this latter approach, several important parameters cannot be dealt with, such as stress history, non-linear behavior, non-homogeneity and anisotropy of the soil outside the sliding wedge. The CA2 (Continuum Analysis, 2-dimensional) computer program is capable of solving slope stability problems, using explicit finite difference method combined with the limit equilibrium concepts. In this paper, the results of continuum Numerical analyses are compared with those of limit equilibrium Methods and the importance of several parameters involved is described.

The suspension system, one of the essential parts of any vehicle which has a significant role in vehicle steering, accelerating, and braking. One of the suspension system's main components is the trailing arm, which is exposed to frequent loadings and is made by welding method. Due to the use and nature of this piece, its fatigue analysis is crucial. Since this part is made by welding process, its fatigue analysis is much more complicated than other parts. In this paper, fatigue life of the trailing arm is investigated by using different Numerical method. At first, safety factor of the component is calculated using dang van criteria. Dang van is one of the most famous and appropriated method for multi axial non proportional loads. However it is not a good criterion in order to calculate the damage of the weld line. So Volvo method that developed base on the weld process and properties is consider for fatigue analysis of the weld line. The obtained results improve the necessity of using this kind of method for welding process. Finally, it could be concluded that for fatigue analysis of a welded component such as trailing arm, using both method are necessary. Considering two different criteria for a component and comparing the obtained results of the trailing arm under non proportional applied load is one of the achievement of this paper. Of course by using this method, the calculated fatigue life of the trailing arm is accurate. At the end, it should be noted that the both applied Methods, Dang Van and Volvo, are completely verified by the available experimental result in the reliable references.

In this article, the 3rd order Numerical acceleration method is presented. The basic assumption of this method is that the acceleration changes in the time interval Δt is in the form of a third degree polynomial, and as a result, its displacement equation, which is obtained by integrating the acceleration equation twice, is a fifth degree curve that has six The coefficient is unknown. To quantitatively compare the error rate of this method with other Numerical Methods, a linear one-degree-of-freedom system with a frequency of one hertz and specific dampings of 1, 2, 5, 10 and 20% was considered. Then, sinusoidal harmonic loading with a specific frequency was applied to this system. The exact answer of this system is available in the books of dynamics of structures. The ratio of the loading frequency to the natural vibration frequency of the system varied from 0.01 to 3 with an increase of 0.01. Using Numerical Methods of second-order acceleration and third-order acceleration and other popular Methods, and using the root mean square error criterion, they were quantitatively compared with each other. The comparison was made for ten Δt, the smallest of which was equal to 0.02 seconds and the largest was equal to 0.20 seconds. The amount of error reduction for the third-order acceleration method was insignificant compared to the second-order acceleration method. The lowest error was related to the upgraded Jennings method, in which the error rate was much lower than other known Methods.