Reshetnikova R. Prediction of bolted joints fatigue durability by local stress-strain state in consideration of clamping force and interference fit

The object - fatigue resistance of bolted joints with the secondary bending, clamping force and interference fit. The aim is the development of durability calculation method for the bolted joints taking into account secondary bending, clamping force and interference fit under the regular and program loading. The proposed method is based on the energy criterion of fatigue failure. Methods that used are method of durability calculation by the local stress-strain state (SSS), finite element method, tensometric method. Practical outcomes: this method gives the opportunity to decrease the amount of faatigue tests during the design process; to use calculation for selection of rational combinations of design and tehnological factorsensouring service life. These calculations utilize the fatigue and cyclic deformation properties of material. Newelty: the method of bolted joints durability calculation, in which the secondary bending, clamping force and interference fit are taken into account; for the first time the approach was proposed to assess the effect of design and technological factors on the stress-strain state using calculation methods exclusively; it was found that the stress gradient in the load-bearing stress concentrators is significantly higher then in the geometrical stress concentratores. Industry sector - aircraft manufacturing.