A Validated Computational Model for the Flexural Response of 3D Hybrid Textile Composites
Dianyun Zhang (University of Michigan), Anthony Waas (University of Michigan)
Prager Medal Symposium in honor of George Weng: Micromechanics, Composites and Multifunctional Materials
Wed 1:30 - 2:50
MacMillan 117
Textile composites are increasingly attractive for industrial applications. A 3D hybrid textile composite has been recently manufactured by weaving three different fibers (carbon, glass, and Kevlar) into a single dry preform, which is subsequently impregnated and cured using a Vacuum Assist Resin Transfer Molding (VARTM) process to form a solid panel. Previous studies in 3D textile composites have shown that this type of material has improved mechanical performance and increased resistance to delamination. We have benefitted greatly from the prior scholarship of Prof. George Weng’s contributions to fiber composites, and in this paper, using some of the work he has presented, we have formulated a new computational multi-scaling approach to study the flexural response of a quasi-statically loaded 3D textile composite. For the experimental work, three-point bend tests were performed on a hydraulically activated machine at a loading rate of 1mm/min. A high-speed camera and the digital image correlation technique (DIC) were utilized to map the deformation and identify the corresponding damage events. The experimental observations suggest that the geometrical characteristics of the textile reinforcement play a key role on the mechanical response and progressive failure mechanism of this type of material. A computational model that reflects the detail of textile architecture and incorporates a damage constitutive law has been used to successfully capture the experimental results. The model has been implemented using a new multi-scaling approach in which the unit cell computations, carried out in closed form, are based on extreme values (as opposed to average values) to drive damage and failure. The resulting computational scheme is shown to be very fast and results in a high-fidelity and efficient computational model for assessing structural integrity and damage tolerance of textile fiber composites.