PSI - Issue 36

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2021) 000 – 000

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 36 (2022) 24–29

© 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the conference Guest Editors Abstract We describe the laboratory facilities that were developed to study the contact phenomena. Developed equipment can be used to measure the forces between two contacting bodies and to analyze the evolution of the contact area. We also present the results of the experiment concerning indentation of the steel sphere into the hardened gelatin solution with following movement of the sphere in tangential direction with constant velocity. It is shown that at tangential displacement (shift) system exhibit stationary stick- slip mode of motion with “stiction spike” at the beginning of the indenter motion. Also, at the beginning of movement, when the contact between gelatin and indenter is strong due to their interaction, we observe the damage of the gelatin surface (the crack propagates from the surface into the gelatin body). This fracture weakens the contact and decreases the tangential friction force. In stationary dynamic stick-slip mode the surface of the gelatin remains undamaged. Similar mechanism of the grain boundary slips in nanostructured metals cause the superplasticity phenomena. © 2022 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the conference Guest Editors Keywords: adhesion; crack propagation; stick-slip; elastomer; friction force; superplasticity; grain boundary 1st Virtual International Conference “In service Damage of Materials: Diagnostics and Prediction” Stick-slip motion in the contact between soft elastomer and spherical hard steel indenter: Model explanation of superplasticity mode in metal samples with grain boundary defects Iakov Lyashenko a,b,* , Vadym Borysiuk b a Technische Universität Berlin , 10623 Berlin, Germany b Sumy State University, 40007 Sumy, Ukraine

* Corresponding author. Tel.: +49-159-0848-3459 E-mail address: i.liashenko@tu-berlin.de

2452-3216 © 2022 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the conference Guest Editors

2452-3216 © 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the conference Guest Editors 10.1016/j.prostr.2021.12.078