DYNAMIC LOAD OF THE THIN CONICAL RADOME WITH A CONSIDERATION OF ATTACHED ADDITIONAL MASS

Abstract

At the present stage of aviation and missile equipment development there is increasing necessity for considering fast-acting, high-speed processes of impact interaction of structure elements with external loads, represented as both power factors (longitudinal force or bending moment) and uniformly spread aerodynamic pressure. The article analyses the dy- namic behavior of the nonuniformly-heated thin conical rotational shell, modelling the aircraft heat shield, under pressure wave loading in a gaseous environment. Stress-strain shell behavior caused by preliminary uneven heating is determined by solving thermo elastic equilibrium equations. The temperature field can be specified as any functional dependence in both circumferential and longitudinal coordinates of a thin-walled axisymmetric shell. The solution of the dynamic problem is obtained by the integration of shell and attached mass motion nonlinear equations under predetermined initial displace- ments, zero initial rates, and boundary conditions appropriate for heat shield fixation. The work presents simultaneous equations solution in the form of time dependent behavior from the beginning of front external pressure impact for dis- placements and stresses in thin-walled structures. The dependent behavior for various shell designs is presented taking into account the changes of shell thickness and attached mass. It is shown that the initial conditions of non-uniform shell heating cause leading-edge deflection comparable in size to the magnitude of the displacements from its free oscillations. However the values of stresses in a shell for its fixation area are more dependent on its thickness, than on the magnitude of the at- tached mass.

Keywords

• heat shield
• shell
• mass
• aircraft
• thermal power loading