دانلود رایگان مقاله ویژگی آئروالاستیک کربن صفحات کامپوزیت نانولوله تحت جریان مافوق صوت

Abstract

Aeroelastic characteristics of nanocomposite plates reinforced by carbon nanotubes and subjected to supersonic flow are investigated. Here, carbon nanotube-reinforced composite plates with five different distributions of carbon nanotube are considered. The material properties are supposed to vary gradually through the thickness of the plate and the rule of mixture is applied to estimate the effective material properties of nanocomposite plate. The governing equations of nanocomposite plate are derived based on Kirchhoff’s plate theory and supersonic aerodynamic pressure is approximated by the first-order piston theory. Galerkin’s method is utilized to obtain the solutions of the coupled governing equations, simultaneously. The suggested model is justified by a good agreement between the results given by present model and available data in the literature. To illustrate the effects of volume fraction, aspect ratio and non-dimensional in-plane forces on the aeroelastic stability of nanocomposite plates, parametric studies have been carried out.

6. Conclusion

We have presented the first attempt to predict the aeroelastic characteristics of the FG-CNTRC plates under the supersonic flow. In spite of some achievement in vibration analysis of the FG-CNTRC plates, to the authors’ knowledge, there has been no attempt to tackle the problem described in the present investigation. Evaluation of the aeroelastic characteristics of FG-CNTRC plates is the main contribution of the present paper. In this work, on the basis of the rule of mixture, the effective properties of the FG-CNTRC plates were obtained. The governing equations of motion were derived by utilizing Kirchhoff’s plate theory and Hamilton’s principle. Since the FG-CNTRC plate is subjected to supersonic flow, the first order piston theory was applied. The critical aerodynamic pressure was obtained for five types of FG-CNTRC plates. The obtained results have been successfully compared to existing data in the literature. To study the aeroelastic behavior, the effects of aspect ratio, non-dimensional in-plane forces and non-dimensional total damping coefficient on the stability boundaries were examined. Based on the numerical results, it was found that with the increase of aspect ratio and total damping, the critical aerodynamic pressure increases. Moreover, it was observed that by increasing the non-dimensional in-plane force in x direction, the critical aerodynamic pressure decreases whereas applying ryy does not affect dynamic stable region. Furthermore, it was revealed that FG-A and FG-V plates have the same aeroelastic behavior. Our results indicated that FG-O plate has the largest stable region with respect to other plates particularly for smaller value of total damping coefficient. The results presented in this paper may be helpful for the aeroelastic analysis of supersonic aero-structures. Finally, it should be noted that the thermal effect can be included in the aeroelastic analysis of the functionally graded carbon nanotube-reinforced composite plates. This would be an interesting issue for future work.