STRESS COMPARISON FOR COMPOSITE GLIDER LIFE-TIME ESTIMATION

Abstract

The method described is based on the compression stress level comparison through the whole cumulative stress spectrum in the selected critical structure component. Experience to date indicates the wing to be the critical component and the critical station to be in the vicinity of the root rib. The stress in the upper spar boom seems to be the most suitable location of the representative stress for predicting the life of the structure. The important thing is how closely the compared gliders meet the requirement of design similarity. The present paper does not pretend to prescribe a complete method to be introduced as standard practice at once; the proposition needs to be discussed and criticized. It can, however, be classified as advisory material in establishing or extending the glider life.