The Tension-Twist Coupling Mechanism in Flexible Composites: A Systematic Study Based on Tailored Laminate Structures...

Area of Science:

• Materials Science
• Composite Materials
• Mechanical Engineering

Background:

• Anisotropic composites with flexible matrices present unique load-coupling challenges.
• Understanding tension-twist coupling is crucial for designing advanced composite structures.

Purpose of the Study:

• To quantify the effect of load-coupling mechanisms in anisotropic composites.
• To develop and verify a novel testing device for investigating tension-twist coupling effects.

Main Methods:

• A modified gripping system was developed for composites with stiff fibers and hyperelastic matrices.
• Verification involved a test plan with glass textile reinforcement and varied lay-ups.
• Analysis focused on the influence of layer number and fiber orientation on load-coupled properties.

Main Results:

• Tension-twist coupling strongly depends on fiber orientation and reinforcing structure.
• Composites with 30°/60° lay-ups achieved twisting angles up to 25° with 82.3 Nmm torque.
• Composites with ±45° lay-ups showed no tension-twist coupling due to symmetric deformation.

Conclusions:

• The novel test device reliably determines load-coupled properties in composites with stiff fibers and hyperelastic matrices.
• Fiber orientation is a key parameter for controlling tension-twist coupling.
• Asymmetric deformation in composites enables significant tension-twist coupling.