ASSESSMENT ON INITIAL FATIGUE QUALITY OF AIRCRAFT TYPICAL CONNECTED STRUCTURE

Abstract

Durability experimental study is performed on single-piece specimens with through-hole and double-piece specimens with fastening holes of three different lengths on random loading. The weak area of structures is gained through threedimensional finite element analysis,considering pre tightening force of bolts and the interference fit between bolts and holes.Based on the results of durability experimental analysis,a new method is put forward to assess the initial fatigue quality（ IFQ） of structures and controlled stress curves are drawn to compare with this method. As a result,the method to assess IFQ of structures in this paper is proved to be effective. The IFQ of double-piece specimens with fastening holes is higher than that of single-piece specimens with through-hole. Furthermore,the IFQ increases with the decreasing of the length of the structure.

Keywords

• Durability;Initial fatigue quality;Equivalent initial flaw size;Finite element analysis