In this study, at first, the maximum WIND speed has been investigated in exchange for different return periods in Ramsar, Nowshahr, Qaemshahr, and Babolsar city. For this reason, data associated with the WIND maximum annual speed in these cities have been collected from 1373 to 1397. To calculate the maximum WIND speed, a first-order Extreme Type I distribution has been used. It has also been attempted to examine the probability of WIND speed distribution of case study cities according to different functions. For this purpose, different functions such as Normal function, Weibull function, Lognormal function, Gamble Max function, Gamma function, and Bur function have been used. Also, in this study, for the design of various functions, the EasyFit software has been used. Results show that the maximum WIND speed, as well as WIND-based pressure for Ramsar, Nowshahr, and Qaemshahr cities, were found to be numerically larger than the Iranian National Building Code (Part 6th). However, for Babolsar, these values are less than the values of the Iranian National Building Code. Unfortunately, the results showed that the design was not safe for Ramsar, Nowshahr, and Qaemshahr cities based on this code, because the structures should be designed to be less than the maximum WIND speed and lower WIND pressure than the actual values. Considering the importance of analyzing and precisely designing structures against WIND and speed WIND, it seems that similar research should be done for other cities to obtain validate and safe values for those cities. Paying attention to this point will lead to more accurate designs in different cities of the country. In addition, results show that for used data, the Weibull function is the best function that can be applied.

Trust FORCE is one of the most dynamic FORCEs that in all periods of WIND turbine operation is to be expected. Usually, dynamic response of the WIND turbine tower under trust FORCEs is calculated using the finite element method. Finite element method has high accuracy but it can considerably increases the computational works depending on the modeling type of foundation and modeling axial FORCE variations. In this paper, transfer matrix method is used to reduce computational works and increase the speed of analysis instead of the finite elements method. For this purpose, the WIND turbine foundation is modeled using DS model and required relations are extracted to determine of WIND turbine response. Then, factors affecting the dynamic response such as induction factor, WIND speed variations and nacelle mass variations are examined in several case studies. Finally, the transfer matrix method obtained results are compared with the results of the finite elements method, multi body dynamics, analytical method and experimental data which show good agreement in spite of low computational cost. The study shows that the vibrations from thrust FORCE, WIND turbine towers is resonance at frequencies equal to twice the natural frequency. Therefore, in the design of WIND turbine towers, tower response at 0.5´wn also be studied.

In this paper, green function and transfer function are used for analytical solution of mass equation, nonlinear spring with effective WIND FORCE. This equation has been used to model space structure, wing and all of the structures used at high altitude. Furthermore this equation is applied frequently in modeling foundation similar to nonlinear spring and the equation is better solved analytically where answer of the analytical solution is similar to the mechanical action.    

In the present research, a building with 45m height and 15m width is exposed to a uniform WIND flow with a velocity of 31m/sec. Finite Element Method (FEM) is utilized to simulate the WIND flow around the building. A two-dimensional model is presented and K-e is used to calculate the turbulence viscosity. The flow field is solved with two different meshes and independency of the results from the meshes has been achieved. The results for dynamic pressure computed by the FEM model are compared with those of ASCE; the results are in good agreement. Limitations of models presented in ASCE are discussed and the reasons of some differences between the FEM results and those of ASCE are presented.

In this paper, green function and transfer function are used for analytical solution of mass equation, nonlinear spring and damping with effective WIND FORCE. This equation has been used to model space structure, wing and all of the structure used at high altitude. Furthermore this equation is applied frequently in modeling foundation similar to nonlinear spring and damping and the equation is better solved analytically where answer of the analytical solution is similar to the mechanical action.

One of the main concerns in renewable energy technologies, such as WIND turbines, is the economic cost and cost savings associated with its construction. Reducing the vibrations of a turbine structure can attenuate the fatigue damage caused by WIND loads led to reduction in material consumption and cost. Besides, if the FORCE and flexural moment at the base of the structure is reduced, a smaller foundation can be used to install the WIND turbine. All of these factors have a positive impact on lowering the cost of a WIND turbine. In this study, application of gyroscopic stabilization to decrease the WIND-induced vibrations in 5 mega Watt WIND turbine is studied. A valid FAST model is employed for this purpose. Moreover, two versions of the gyroscopic actuator including a passive stabilizer and an active gyroscopic actuator has been proposed. Furthermore, a PID controller has been designed to control the active system. The effect of gyroscope actuator on vibration, shear FORCE and bending moment caused by WIND loads is studied via extensive simulations. It was shown that the proposed system can reduce the decease the tip vibration, base shear and base moment by 32 percent in active mode and 14 percent in passive mode. As a result enclosing circle of foundation reduces 5 meter.

In the WIND tunnels, the balance measurement instrument is used to measure six components of FORCE and moment on an airplane model. The balance of measurement consists of two parts of the balance structure and electronic equipment. In this research, a mechanism with flexible hinges is designed to achieve the desired configuration of the balance structure. In the process of designing the geometric structure of this mechanism, an effective arrangement has been implemented for the six load cell-flexure columns. The advantages of flexible hinges in comparison to conventional hinges are the absence of friction, compactness and its linear behavior. The reaction effects of the components of FORCE and moment on each six load cell-flexure columns created the coupling errors. One of the main sources of this kind of error is related to the structure of the balance mechanism. The reason for this type of error is the inadequacy of the axial flexibility to the lateral flexibility of the columns. The aim of this research is to optimize the design of the flexible mechanism in order to achieve the minimum coupling error of the structure. For this purpose, hinge design considerations and analytical equations of the flexible mechanism have been extracted. The design of the balance mechanism is optimized by creating a structure coupling error matrix. To validate the analytic equations and results, the problem is compared with the finite element analysis. The results indicated that the measurement errors decrease in the measurement of six components of FORCE and moment of balance.