PSI - Issue 28

M.Z. Sadeghi et al. / Procedia Structural Integrity 28 (2020) 1590–1600 M.Z. Sadeghi et al./ Structural Integrity Procedia 00 (2020) 000–000

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Fig. 11. Influence of combined effect on longitudinal strain versus normalaized force.

5. Conclusions In this work the effects of different parameters on the backface strain measurement in SLJ adhesively bonded joint were examined. A position for mounting the strain gauge was introduced in the present work. The strain on this position is zero and remains without change as long as the damage in the joint is not induced. Once the damage in the joint is formed, the former so-called zero strain point gains strain values. Therefore, this point shows high potential for structural damage indicator (SDI) in such joints. The effect of geometric tolerances existing in the assembly process of adhesively bonded SLJ, misalignment of strain gauge installation on the adherent as well as temperature variation was investigated in the present work. Further investigation needs to be still done to find correlation of the combined effect of bending/torsion moments on the measured back-face strain. In addition, the effect of influential parameters on the backface strain should be under cycling loading (preferably with variable amplitude loading) should be investigated which is the real loading case for such joints while they are in service. Acknowledgements The authors wish to thank the Federal Ministry for Economic Affairs and Energy of Germany for the financial support received under the frame work of IGF-project (IGF-Nr. 19909 N / 2, “SmartSHM – Effiziente Zustandsüberwachung struktureller Klebungen) by the research association “DECHEMA Gesellschaft für Chemische Technik und Biotechnologie e.V.". Furthermore, the authors would like to thank 3M Deutschland GmbH (Mr. Julius Weirauch and Mr. Tobias Waffenschmidt) for providing the adhesive 3M Scotch-Weld DP 490 and the its material

parameters. References

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