Analysis of the thermomechanical shear behaviour of woven-reinforced thermoplastic-matrix composites during forming

Towards comprehensive characterisation and modelling of the forming and wrinkling mechanics of engineering fabrics

“…The UBE test has been discussed extensively in the literature (Boisse et al, 2016;Cao et al, 2008;Harrison et al, 2008;Machado et al, 2016) and involves clamping a piece of biaxial fabric such that the warp and weft tows are orientated initially at +/-45 o to the direction of the applied tensile force. The sample's length / width ratio ( = ) ⁄ , must be at least two.…”

“…The uniaxial bias extension (UBE) test is typically used to measure the shear compliance of engineering fabrics and prepregs (Boisse et al, 2016;Cao et al, 2008;Harrison et al, 2012Harrison et al, , 2008Machado et al, 2016). In this investigation it will also be employed to identify both the in-plane bending stiffness (D'Agostino et al, 2015;Dell'Isola and Steigmann, 2014;Ferretti et al, 2014;Giorgio et al, 2016;Harrison, 2016;Scerrato et al, 2016;Turco et al, 2016) and the torsional stiffness of the sheared fabric (Lomov and Verpoest, 2006;Steigmann and Dell'Isola, 2015) by monitoring the sample kinematics, including the shear angle at the centre of the specimen (D'Agostino et al, 2015;Ferretti et al, 2014;Harrison, 2016) and the out-of-plane wrinkling behaviour (Arnold et al, 2016;Boisse et al, 2011;Cherouat and Billoët, 2001;Dangora et al, 2015;Harrison, 2016;ten Thije and Akkerman, 2009;Thompson et al, 2016).…”

Experimental characterization and modeling of the temperature and rate-dependent shear behaviour of powder-impregnated glass fiber/PA66 woven semipregs

“…9). The effect of temperature on the shear behaviour of woven composites is well documented in the literature [17,25,32], and is attributed to the increase in viscosity of the thermoplastic matrix as the material cools from the melt. A higher viscosity at lower temperatures impedes the shearing of the yarns that are either fully impregnated (in the case of the preconsolidated fabric) or sandwiched between polymer rich layers (in the case of the semipreg).…”

“…The temperature and ratedependence is assumed to be related only to the in-plane shear term and tension/shear couplings are neglected (although recent work has shown that tension in the yarns can affect the shear response through an increase of the contact forces at crossover points [42]; an uncoupled model is however sufficient to predict the shear deformation patterns [43]). The analytical expression of the shear modulus developed by Machado et al [32] for preconsolidated composites is used to represent the nonlinear, temperature and rate-dependent shear behaviour. This empirical model assumes a multiplicative decoupling between the different effects (eq.…”

Active Thermography for Automated Testing of Composite Structural Components

“…The high values of the dark-red areas can be explained, for example, by extraneous materials with high temperature conductivity or by thin walls. In this case, the identified quality variations are also due to the production process [13,14]. However, knowledge about production is no longer necessarily required to evaluate the results.…”