The Tension-Twist Coupling Mechanism in Flexible Composites: A Systematic Study Based on Tailored Laminate Structures Using a Novel Test Device

Abstract

The focus of this research is to quantify the effect of load-coupling mechanisms in anisotropic composites with distinct flexibility. In this context, the study aims to realize a novel testing device to investigate tension-twist coupling effects. This test setup includes a modified gripping system to handle composites with stiff fibers but hyperelastic elastomeric matrices. The verification was done with a special test plan considering a glass textile as reinforcing with different lay-ups to analyze the number of layers and the influence of various fiber orientations onto the load-coupled properties. The results demonstrated that the tension-twist coupling effect strongly depends on both the fiber orientation and the considered reinforcing structure. This enables twisting angles up to 25° with corresponding torque of about 82.3 Nmm, which is even achievable for small lay-ups with 30°/60° oriented composites with distinct asymmetric deformation. For lay-ups with ±45° oriented composites revealing a symmetric deformation lead, as expected, no tension-twist coupling effect was seen. Overall, these findings reveal that the described novel test device provides the basis for an adequate and reliable determination of the load-coupled material properties between stiff fibers and hyperelastic matrices.

Microvascular engineering for the development of a non-embedded liver sinusoid with a lumen: when endothelial cells do not lose their edge

“…By initially imposing a lateral strain to this confined region, the mechanical instability linked to stretching resembles a shear-driven plane buckling, caused by a tensile load, as described for non biological materials 64 . This phenomenon, stunningly similar to the patterns found in our experiments, occurs when a soft sheet of material suffers an out of plane deformation upon extended longitudinal tension 65 , resulting in out-of-plane longitudinal wrinkles or infolds 66 . The direction, length and deformation threshold needed to initiate these deformations are defined by the interplay between external stress and orientation of the superficial or inner substructure of the material 67 .…”

“…In our experiments, however, the mechanical instability seems linked to stretching rather than compression and resembles a shear-driven buckling, where a soft sheet of material suffers an out of plane deformation like a transverse shrinking upon extended longitudinal tension (54). Its formal description is complex to explain, but accounts for the appearance of out of plane longitudinal wrinkles or infolds (55). These 2D to 3D transformations usually appear on planar materials with a pre-oriented superficial or inner substructure (usually fibrous), a role that our ECM pattern can play.…”

The Influence of Friction and Twisting Angle on the Tensile Strength of Polypropylene Baling Twine

“…The PP matrix can be combined with reinforcement and used for various raw materials, semi-finished products, or textile fabrics. [19][20][21][22][23][24][25]. Rocher et al [26] investigated the tensile behaviour of a 3D polypropylene/glass fabric at different test speeds.…”

Tailored Interfaces in Fiber-Reinforced Elastomers: A Surface Treatment Study on Optimized Load Coupling via the Modified Fiber Bundle Debond Technique

“…Furthermore, this can be exploited for several other material clusters based on the requirements of the individual components in the composite. In adaption to this aspect combined with a systematic scaling from micro- to macro-mechanical properties, the profound findings regarding the adhesive fiber–matrix strength resulting in an optimized load coupling in the composite yield the basis for promising approaches, such as tension-twist coupling in fiber-reinforced elastomers [ 55 ] for novel smart composite material applications, such as aeroelastic spoilers, flaps or aileron in the aircraft and automotive sectors.…”