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

design of the main pivot on the forced oscillation apparatus FOR THE WIND TUNNEL MEASUREMENTS

Marija Samardžić

Military Technical Institute, Belgrade, majasam@ptt.rs

Dragan Marinkovski

Military Technical Institute, Belgrade, marinkovskid@ikomline.net

Dušan ćurčić

Military Technical Institute, Belgrade, dusan.curcic@vti.vs.rs

zoran rajić

Military Technical Institute, Belgrade, zoran.rajic@vti.vs.rs

abdelwahId boutemedjet

Military Academy, Belgrade, abdelwahed1954@gmail.com

Abstract: The main pivot on the forced oscillation apparatus for dynamic measurements in the T-38 wind tunnel is described in this paper. Design of such element is complicated by restricted space inside the wind tunnel models. The pivot of the T-38 forced oscillation apparatus is formed from a pair of symmetrical cross-flexures. Two types of the cross-flexures are presented: cross-flexures with uniform cross-section of the strips and cross-flexures with variable cross-section of the strips. Stress analysis of the cross-flexures showed that strips with variable cross-section much better matched strict requirements of the dynamic wind tunnel measurements.      

Keywords: flexure pivot, oscillations, wind tunnel, dynamic stability derivatives.