PSI - Issue 56

Alexandru Isaincu et al. / Procedia Structural Integrity 56 (2024) 167–175 Alexandru Isaincu / Structural Integrity Procedia 00 (2019) 000 – 000

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1. Introduction High performance engineering polymers with glass fiber reinforcement are more often than ever used in the automotive industry. The harsh requirements arising from the automotive industry are transferred to the material manufacturer. One of the main advantages of these types of materials is good mechanical properties compared with the density. A lightweight component can result in the end. A second advantage is that mass scaled production using complex shapes and low production costs can be achieved. These materials can be seen in chassis and suspension load bearing applications as well as traditional powertrain component applications. Understanding how these types of materials work and what are the limitations in terms of performance is required for an efficient design.

Nomenclature PPA

polyphthalamide GF33 33% glass fiber inclusions PPS polyphenylene sulfide GF40 40% glass fiber inclusions SEC single edge crack SFRP short fiber reinforced polymers t

thickness of the single edge notch specimen length of the single edge notch specimen width of the single edge notch specimen

L b a h

notch length/depth

griping distance of the single edge notch specimen

SIF K I K Ic

stress intensity factor of a crack mode I stress intensity factor mode I fracture toughness

The aim of this work is to investigate the influence of fiber orientation and material thickness on the fracture toughness of PPA GF33 and PPS GF40 materials determined on SEC specimens. The effects on the mechanical behavior due to the fiber orientation was studied extensively in Holmström, Hopperstad and Clausen (2020), Bernasconi et al. (2007) and many others. When it specifically comes to fracture toughness, a small number of studies were published for SFRP. For PPS, some values of fracture toughness can be found in Friedrich (1985); Karger-Kocsis and Friedrich (1987), Tanaka, Kitano and Egami (2014). Determining and understanding fracture toughness is extensively presented in Nelson, Li and Kamada (2002) Ramirez, Carlsson and Acha (2009), Soderholm (2010), Limited (2012) Garcia-Manrique et al. (2018). The fracture toughness of these two particular materials was previously determined using edge crack triangular specimen in Isaincu, Micota and Marsavina (2022). In this paper, the fracture toughness of PPA GF33 and PPS GF40 is studied by means of physical testing and

analytical interpretation. 2. Experimental details 2.1. Materials

Two SFRP are considered for this study: a PPA with 33% glass fiber content and a PPS with 40% glass fiber. The materials are provided by the Solvay Group and can be found on the market under the trade name Amodel AE-4133 and Ryton R-4-270 respectively. The amount of fiber, in terms of percentage, refers to the weight of the composite. The average dimension of a fiber, according to the material supplier, is in the range of 10 μm for the diameter and 200 μm for the length . The distribution fiber length probability density versus fiber length for a similar material can be