PSI - Issue 53

A. Neto et al. / Procedia Structural Integrity 53 (2024) 338–351 Alexandre de Oliveira Neto / Structural Integrity Procedia 00 (2019) 000–000

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deformation on different layups, and to obtain a classification of the structural integrity of a composite tube under gradient low-speed impact tests as this study aims to achieve. 2. Numerical method 2.1. Test apparatus There are entities such as ASTM (American Society for Testing and Materials), ISO (International Organisation for Standardization), SAE International (Society of Automotive Engineers International), ACI International (American Concrete Institute International) and AIAA (American Institute of Aeronautics and Astronautics) that have developed standards and standardised tests for testing composites, among others. According to the carried out research, ASTM and ISO are the organisations that have tests that best apply to mechanical tests on composites, such as tension, traction, compression, torsion, and impact conditions. The ASTM D7136/D7136M-15 standard determines the damage resistance of a composite plate when subjected to a low-velocity impact from falling weight. This testing methodology apparatus can be used to characterise material properties, assess structural integrity and more. It can be applied to tubular structures using an appropriate sample geometry as well as boundary conditions in accordance with the standard. The drop weight test apparatus (Fig. 1) was modelled in LS-DYNA®, based on the previously mentioned ASTM D7136 but applied to tubular profiles. Using an impactor with 5,5 kg and semi-spherical geometry with a programmed energy gradient, aluminium supports at each end, and a CFRP tubular profile.

Fig. 1. Drop weight simulation apparatus in LS-Prepost

A differentiating factor of this study is the fact that the 12 composite layers were modelled and meshed individually so that they could be evaluated (Fig. 2).

Fig. 2. Individual layer modelling