PSI - Issue 28

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Barış Tanrıkulu et al. / Procedia Structural Integrity 28 (2020) 1267 – 1275 Author name / Structural Integrity Procedia 00 (2019) 000–0 0

1274

Fig. 6. Plate deformation caused by rip form during different tightening strategies.

Table 2. Loosening Rate values of test combinations Experimental test Plate Hardness Nut Type

Loosening rates (kN / Cycle)

Tightening Strategy Bolt Head Nut Head Nut Head Bolt Head Nut Head Nut Head Bolt Head Nut Head Nut Head

Clamp Length 29 mm 29 mm 29 mm 40 mm 40 mm 40 mm 40 mm 40 mm 40 mm

Set 1 Set 2 Set 3 Set 4 Set 5 Set 6 Set 7 Set 8 Set 9

175 HV 175 HV 175 HV 175 HV 175 HV 175 HV 300 HV 300 HV 300 HV

Rip Nut Rip Nut Plain Nut Rip Nut Rip Nut Plain Nut Rip Nut Rip Nut Plain Nut

0,04155 0,02939 0,02619 0,00017 0,00122 0,03354 0,00217 0,00612 0,03701

4. Conclusion Based on the experimental studies conducted in this study, following conclusions can be drawn:

1. Considering experimental test result, tightening strategy has a major effect on the loosening behavior of ripped nuts. Tightening from bolt side increases the loosening resistance of the assembly by causing plastic deformation on the plate with the rip form of the nut. However, when tightening is performed by the rip shaped nut, the deformation on the plate is in the form of a channel leading to decrease in the loosening resistance. Among the two tightening strategy and plain nut combination the best performance was obtained by tightening from bolt side, tightening from nut side, and plain nut respectively.