Damage failure analysis for composite bolted joints with tightening torque subjected to static loadings;

Aimed at reducing vibration and early failure of engine components caused by inappropriate tightening torque exerted on cylinder head bolts, the relationship between tightening torque of bolts and vibration of engine block is studied in this paper by means of vibration testing system developed on virtual instrument.

Methods Six fixed lumbar cadavers were collected, the effects of design parameter, insertion torque and etc on fixation stability were determined under various BMD by using biomechanical ways.

The establishment method of srew tightening force－torque diagram is introduced, the application of the diagram to the design of tightening process for torque tightening method is presented, and the applications to the selection of srew grade and size and to the deciding the torque for screw delay fracture test are described.