PSI - Issue 72

Available online at www.sciencedirect.com

ScienceDirect

Procedia Structural Integrity 72 (2025) 69–76

12th Annual Conference of Society for Structural Integrity and Life (DIVK12) Characterization of the mechanical properties and fracture toughness of sheet molding compound P.M.M. da Silva a , R.D.S.G. Campilho a,b, *,A.J.A. Vieira a , A.L. Faria a , K. Madani c , A. Houari c , M.A. Bellali c a CIDEM, ISEP – School of Engineering, Polytechnic of Porto, R. Dr. António Bernardino de Almeida, 431, 4200-072 Porto, Portugal. b INEGI – Pólo FEUP, Rua Dr. Roberto Frias, 400, 4200-465 Porto, Portugal. c Department of Mechanical E ngineering, University of Sidi Bel Abbes, BP 89, Cité Ben M’hidi, 22000, Sidi Bel Abbes, Algeria. Abstract This work addresses the Sheet Molding Compound (SMC) mechanical behavior and fracture toughness with different glass fiber volume fractions (FVF). Bulk (tensile test) and block shear (shear test) mechanical tests were carried out. By double-cantilever beam (DCB) and end-notched flexure (ENF) tests, the fracture toughness in tension ( G IC ) and shear ( G IIC ), respectively, were estimated. In conclusion, it was possible to estimate that the SMC properties under different conditions and testify the improvement of both mechanical and fracture properties with the amount of reinforcement fibers. With the acquired results, during the design of composite structures, it is possible to select a SMC type safely withstands the imposed loading. © 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 Aleksandar Sedmak, Branislav Djordjevic, Simon Sedmak Dr. Simon Sedmak, ssedmak@mas.bg.ac.rs, Innovation Center of Faculty of Mechanical Engineering, Belgrade, Serbia

Keywords: Sheet moulding compound; Fibre volume fraction; Mechanical testing; Fracture toughness

1. Introduction In recent decades, composites began to gain importance due to environmental concerns and cost reduction. Nowadays, composites can be found in practically every industry, such as the furniture industry with medium density fiberboard (MDF) and honeycomb, the automotive industry with SMC, or in aeronautics with carbon fiber

* Corresponding author. Tel.: +351939526892; fax: +351228321159. E-mail address: raulcampilho@gmail.com

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 Aleksandar Sedmak, Branislav Djordjevic, Simon Sedmak Dr. Simon Sedmak, ssedmak@mas.bg.ac.rs, Innovation Center of Faculty of Mechanical Engineering, Belgrade, Serbia 10.1016/j.prostr.2025.08.075