Experimental investigations into the application of direct tension indicators with preloaded structural bolting assemblies (HV system) to EN 1090-2

EN 1090-2 provides several tightening methods for the preloading of bolting assemblies. One of the prescribed procedures is the use of direct tension indicators, so-called DTIs, with lubrication according to k-class K0. According to the definition of k-class K0, the lubrication should not have an influence on achieving the required preloading force Fp,C. For this reason, the main focus of the investigations presented here was how the lubrication influences the behaviour of preloaded HV bolting assemblies with and without DTIs. The experimental investigations were carried out on the institute's own tightening torque testing machine.