Predicting the Compression-After-Impact (CAI) strength of damage-tolerant hybrid unidirectional/woven carbon-fibre reinforced composite laminates

Abstract

The evaluation of Compression-After-Impact (CAI) strength is of great significance in the design of composite aerostructures. This paper presents a model for the numerical simulation of Compression-After-Impact (CAI) of hybrid unidirectional (UD)/woven carbon-fibre reinforced composite laminates. This three-dimensional damage model is based on Continuum Damage Mechanics (CDM) and Linear Elastic Fracture Mechanics (LEFM), and implemented as a user defined material subroutine (VUMAT) in Abaqus/Explicit. This model, which accounts for interlaminar and intralaminar damage, and load reversal, incorporates a non-linear shear profile to account for matrix plasticity. Two different composite laminate lay-ups with varying extent of initial impact damage were tested to validate the computational model and enable a quantitative study of the influence of using woven plies on the surfaces of a laminate. Woven surface plies are often used in composite aerostructures to mitigate damage during drilling and constrain the extent of damage during low velocity impact. Good correlation was obtained between physical testing and simulation results, which establishes the capability of this damage model in predicting the structural response of composite laminates. The fully validated model was used to compare the Compression-After-Impact (CAI) strength of an equivalent unidirectional (UD)-only carbon-fibre reinforced composite laminate. The results showed that the hybrid unidirectional (UD)/woven laminate had a marginally higher strength (+3.3%) than the equivalent unidirectional (UD)-only laminate.

The Impact Performance of Woven-Fabric Thermoplastic and Thermoset Composites Subjected to High-Velocity Soft- and Hard-Impact Loading

“…To calculate and compare the values of the contact pressures caused by the soft-gelatine projectiles and hard aluminium-alloy projectiles, the impact behaviour of the CF/PEEK composite target was modelled. The relevant material properties of the CF/PEEK composites required for the modelling studies may be found from the literature [11,12,15,[48][49][50][51][52][53][54] and are given in Table 4.…”

“…It can be seen that the aluminum-alloy impacted CF/PEEK composite exhibited a significantly higher reaction force than the gelatineimpacted CF/PEEK composite. The maximum reaction forces associated with the soft-gelatine Table 4 The input parameters for the composite damage model [11,12,15 Fig. 15 The FE model for simulating (a) the soft-gelatine particle (PC3D) impact and (b) the hard aluminiumalloy projectile impact on the composites and the hard aluminium-alloy impacts on the CF/PEEK composites were calculated to be 4.4 kN and 7.4 kN, respectively, see Fig.…”

“…With this in mind, the impact performances of composites, such as the conventional nontoughened and toughened thermosetting epoxy-matrix composites [7][8][9][10][11], thermoplasticmatrix composites [12][13][14], and three-dimensional woven-fabric fibre composites [15][16][17], have been studied. In industrial applications, the carbon-fibre reinforced-epoxy (CF/epoxy) composites have been extensively employed in civil aircraft, due to their relatively high performance and the relative ease of manufacturing large and complex structures from this type of composite material [18,19].…”

Compressive failure of woven fabric reinforced thermoplastic composites with an open-hole: An experimental and numerical study

“…The failure modes, including delamination, fibre damage and matrix damage [21,23], which may occur in a woven composite ply are shown in Fig. 1a.…”

Blast resilience of composite sandwich panels with hybrid glass-fibre and carbon-fibre skins

“…The air blast load on the sandwich panels was implemented as a time-dependent pressure using the tabular function in Abaqus. The general contact algorithm was used for global contact and a friction coefficient of 0.2 was used for the steel/composite contact surface (Falzon et al 2017;Liu et al 2018).…”