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

341

4

In Table 1 the LS-DYNA® Mesh, MAT, and Simulation Parameters will be shown accordingly.

Table 1. LS-DYNA® Mesh, MAT, and Simulation Parameters

Number of elements

649981

Mesh

Tetrahedron (supports and impactor) and Solid elements (CFRP layers) 001-Elastic 024-PIECEWISE_LINEAR_PLASTICITY 054/ 055 ENHANCED_COMPOSITE_DAMAGE

Element type

Steel impactor Aluminium supports Carbon fibre composite layers

MAT

Consistent units Contact

kg, mm, ms, kN, GPa, J AUTOMATIC_GENERAL

Hourglass ELFORM Timestep D3PLOT

4 – Flanagan-Belytschko stiffness form EQ. 1: Constant stress solid element

Simulation

0.001

0.15

2.2. LS-DYNA® parameters In order to determine the MAT function that allows for the modelling of chosen TORAYCA T300 carbon fibre, there is a need to understand what failure criteria are aligned with this study’s objective. Abdul-Salam Kaddour and Michael J. Hinton (2000) organised an international initiative aimed at accurately predicting the strength of composite materials, dubbed the World-Wide Failure Exercise or WWFE. The main objective was to provide a comprehensive description of the failure/rupture theories of CFRP panels. The WWFE consists of three different exercises, with the degree of complexity of the stress states increasing from the first to the last. From a development point of view, the authors then state that the interpretations of the results of the exercises can help to minimise the component's weaknesses regarding structural integrity in the following aspects:

Sample dimensions;

      

Prediction of initial stiffness; Prediction of initial rupture; Development of crack density; Development of major damage; Final strength prediction;

Structural analysis. Consequently, it is necessary to carefully review the WWFE exercises in order to better select the most appropriate failure criterion for this case study, in order to increase the chances of obtaining better structural integrity results as mentioned in the previous list, thanks to the work carried out by the authors. Taking into account the need to quantify the tubular profile’s resistance, in order to study which type of stacking might be most favourable, after careful analysis, it is concluded that the most appropriate failure criterion is "Tsai", which means in the context of the image the Tsai-Wu criterion. When compared to the others, according to Fig. 3, the chosen base criterion proves to be the one that best manages to predict initial failure due to damage, its delamination and rupture (final failure).