PSI - Issue 82

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2026) 000–000

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 82 (2026) 125–130

© 2026 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 ICSID organizers fatigue failure remains absent irrespective of the number of cycles. The “traditional” fatigue limit is precisely such a parameter for fatigue strength. Herein, this paper defines intrinsic strength parameters in different fatigue regimes, takes a forged titanium alloy (Ti62A) as the experimental material, and applies these parameters to quantitatively characterize the occurrence probability of the so-called very-high-cycle fatigue (VHCF), where failure cycles exceed 10 7 , and the effect of tensile mean stress on this distribution of VHCF occurrence. © 2026 The Authors. Copy from the contract: 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 ICSID organizers Keywords: strength; fatigue limit; failure probability; very-high-cycle fatigue (VHCF); titanium alloy 8th International Conference on Structural Integrity and Durability (ICSID2025) Definition and application of intrinsic fatigue strength parameters: A case study on Ti62A forged alloy Xiangnan Pan* LNM, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China Abstract Unlike yield strength, tensile strength, and other such strength quantities, fatigue strength is not an inherently clear concept, as it must be linked to a specific fatigue life. Due to factors related to the material itself and specimens, scatter is present, leading fatigue strength to exhibit a distribution. However, due to the limitation of the number of specimens, fully obtaining this distribution is quite challenging; thus, certain parameters are commonly employed to characterize the fatigue strength. In fatigue analysis of carbon steels and other analogous materials, the traditional perspective posits the existence of a fatigue limit σ w that corresponds to a fatigue life of 10 7 cycles. Under such loading conditions (i.e. applied stress amplitude σ a or maximum stress σ max below σ w ),

* Corresponding author. Tel.: +86 134 8872 5866. E-mail address: panxiangnan@lnm.imech.ac.cn

2452-3216 © 2026 The Authors. Copy from the contract: 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 ICSID organizers

2452-3216 © 2026 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 ICSID organizers 10.1016/j.prostr.2026.04.020