REPUBLIC OF SERBIA

MINISTRY OF DEFENCE

www.mod.gov.rs

MINISTRY OF DEFENCE

Material Resources Sector

Defensive Technologies Department

Military Technical Institute

www.vti.mod.gov.rs

divergence analysis of thin composite plates in subsonic and transonic flows

mirko dinulović

University of Belgrade, Faculty of  Mechanical Engineering, Belgrade, Serbia, mdinulovic@mas.bg.ac.rs

ALEKSANDAR GRBOVIĆ

University of Belgrade, Faculty of  Mechanical Engineering, Belgrade, Serbia, agrbovic@mas.bg.ac.rs

danilo petrašinović

University of Belgrade, Faculty of Mechanical Engineering, Belgrade, Serbia, dpetrasinovic@mas.bg.ac.rs

Abstract: In the present paper the static aeroelastic phenomenon known as torsional divergence is investigated on rocket stabilizers (fins) made of composite materials. Using analytic approach, the differential equation for torsional divergence of composite trapezoidal stabilizer is derived. The equation obtained was in the form of second order differential equation with variable coefficients. The solution to divergence equation was obtained using Galerkin's approach and the complete solution procedure is presented. Required material elastic coefficients were calculated using micro-mechanics composite analysis for lamina, and classical lamination theory (CLT) for complete stabilizer laminate lay-up.

It was found that Galerkin's approach can be successfully deployed in solving differential divergence equation and divergence speed (VD) of composite stabilizer in subsonic air-flow can be effectively calculated.