Calculation of elastic deformation under the influence of high velocity impact on composite plate structures.

Composite materials are widely used in many civil and military applications because of their excellent mechanical properties. In military applications, composite materials are used to protect vehicles and aircraft and to manufacture shields for their ability to absorb and disperse impact energy. In this paper, used high velocity impact with a bullet (it mass of 8 g, diameter 9 mm and a semi-circular projectile head) with a specific velocity ranging from 210 - 365 m/s, to investigate the elastic deformation for composite plate structure with various composite laminated parameters effect. Where, studied the effect of the impact by using theoretically technique, in addition to, calculating the natural frequency for plates by using analytical and numerical techniques, and then, comparison the results obtained. In the theoretical part, problems were analysed into several categories, the first is the calculation of the elastic deformation in the composite materials samples which depends on several parameters such as the calculation of the natural frequency, the time and force contact, and elastic deformation. An equation for the calculation of elastic deformation was derived based on the classical theory of plates. Also, the natural frequency results calculated analytically by using classical theory of plates with drive the general equation of motion. Then, by using numerical technique calculating also the natural frequency of plates, and then, comparison the results obtained with analytical results obtained. When, the numerical technique include using for finite element technique to calculate the vibration behaviour for plate. Then, the comparison for results given a good agreement for analytical technique used with maximum error did not exceed about (1.23%). [ABSTRACT FROM AUTHOR]