PSI - Issue 77

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

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 77 (2026) 215–220

© 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 ICSI organizers © 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 ICSI organizers Abstract The mechanical interaction at the limb–socket interface is a critical determinant of user comfort and skin integrity; however, the specific contributions of the coefficient of friction (μ) and Poisson’s ratio (ν) have not been quantitatively established. Objective: The objective of this work is to evaluate how μ modulates stresses in the residual limb and its potential association with so cket safety, and to determine how ν governs socket maximum stress and structural safety margins . Methods: Above-knee finite element (FE) model (elastic-plastic socket/base, first- order Ogden limb, rigid femur; C3D4H mesh) with parametric sweeps of μ (0.30– 1.00) and ν (0.10 –0.49) across polyethylene (PE), polyethylene terephthalate glycol (PETG), and high-performance carbon-fiber-reinforced polymers (HCFRPs). Results: Residual limb soft- tissue maximum Von Mises stress showed a U-shaped dependence on μ with a minimum near 0.7; the socket stress -to- yield ratio was largely insensitive to μ but differed by material (largest margin for HCFRPs , intermediate for PETG, smallest for PE). Increasing ν reduced socket maximu m Von Mises stress by ~16–18% from 0.10 to 0.50 for all materials, with the ranking of safety margins (HCFRPs > PETG > PE) consistent with that observed in the μ analysis . Conclusions: Specifying a mid- range μ (~0.7) together with socket materials of higher ν (0.40 –0.50) constitutes an effective strategy to reduce soft-tissue stresses while preserving structural safety, thereby offering biomechanical criteria for liner selection and material specification. © 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 ICSI organizers International Conference on Structural Integrity Balancing comfort and safety in transfemoral prosthetic sockets through finite-element modelling of interface mechanics Fang Liu a , Daniel T. P. Fong b , Simin Li a, * a Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough, LE11 3TU, Leicestershire, UK b National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, LE11 3TU, UK Abstract The mechanical interaction at the limb–socket interface is a critical determinant of user comfort and skin integrity; however, the specific contributions of the coefficient of friction (μ) and Poisson’s ratio (ν) have not been quantitatively established. Objective: The objective of this work is to evaluate how μ modulates stresses in the residual limb and its potential association with so cket safety, and to determine how ν governs socket maximum stress and structural safety margins . Methods: Above-knee finite element (FE) model (elastic-plastic socket/base, first- order Ogden limb, rigid femur; C3D4H mesh) with parametric sweeps of μ (0.30– 1.00) and ν (0.10 –0.49) across polyethylene (PE), polyethylene terephthalate glycol (PETG), and high-performance carbon-fiber-reinforced polymers (HCFRPs). Results: Residual limb soft- tissue maximum Von Mises stress showed a U-shaped dependence on μ with a minimum near 0.7; the socket stress -to- yield ratio was largely insensitive to μ but differed by material (largest margin for HCFRPs , intermediate for PETG, smallest for PE). Increasing ν reduced socket maximu m Von Mises stress by ~16–18% from 0.10 to 0.50 for all materials, with the ranking of safety margins (HCFRPs > PETG > PE) consistent with that observed in the μ analysis . Conclusions: Specifying a mid- range μ (~0.7) together with socket materials of higher ν (0.40 –0.50) constitutes an effective strategy to reduce soft-tissue stresses while preserving structural safety, thereby offering biomechanical criteria for liner selection and material specification. International Conference on Structural Integrity Balancing comfort and safety in transfemoral prosthetic sockets through finite-element modelling of interface mechanics Fang Liu a , Daniel T. P. Fong b , Simin Li a, * a Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough, LE11 3TU, Leicestershire, UK b National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, LE11 3TU, UK

* Corresponding author. Tel.: +441509227630; fax: +0-000-000-0000 . E-mail address: s.li@lboro.ac.uk. * Corresponding author. Tel.: +441509227630; fax: +0-000-000-0000 . E-mail address: s.li@lboro.ac.uk.

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 ICSI 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 ICSI 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 ICSI organizers 10.1016/j.prostr.2026.01.029