The high strain rate tension behaviour of pseudo-ductile high performance thin ply composites

Abstract

In this study the effect of strain rate in tension on two different types of thin-ply pseudo-ductile laminates is reported. These comprised Unidirectional (UD) and quasi-isotropic (QI) hybrids made from low strain thin-ply carbon/epoxy and high strain glass/epoxy prepreg and all-carbon laminates made from thin-ply [±ϴ/0]s laminates referred to as angle-ply (AP) composites. Laminates were designed and subjected to a range of cross-head speeds from 2 mm/min (0.0003 s-1) to 10 m/s (100 s-1). The designed laminates were made from single or hybrids of low strain and high strain unidirectional prepregs, i.e. thin-ply Carbon/epoxy and Glass/ epoxy, respectively. Dynamic stress-strain plots and details of the damage mechanisms were obtained for each sample and compared with the quasi-static test results. The investigated thin-ply UD and QI hybrid composite laminates showed excellent pseudo-ductility at different strain rates, whereas the AP laminates were strain rate dependent and pseudoductility decreased with increasing strain rate.

Multivariable Signal Processing for Characterization of Failure Modes in Thin-Ply Hybrid Laminates Using Acoustic Emission Sensors

“…Consequently, the discrepancy in strain rate did not influence the progression of damage. Previous research [19] has already examined the impact of strain rate, revealing only minor alterations in failure mechanisms at high speeds (5-10 m/s). As a result, we do not anticipate any discernible effects on the failure mechanisms due to the slight difference in loading rates (2 mm/min vs. 1 mm/min).…”

Investigating the fatigue behaviour of quasi-isotropic pseudo-ductile thin-ply carbon/glass epoxy hybrid composites

“…In order to study the suitability of PDH composites in real-life applications, these composites were investigated at high strain rates and off-axis loadings. QI and UD PDH composites were seen to have excellent pseudo-ductile responses both in quasi-static and high strain rates through fragmentation and stable pull-out of the carbon layers [14]. An increase in the off-axis angle of the QI laminates did cause small changes in the pseudo-ductile strain and maximum stress values, however, the laminates still showed a pseudo-ductile response [15].…”

Visualizing pseudo‐ductility in carbon/glass fiber hybrid composites manufactured using infusible thermoplastic Elium® resin

“…[20] Therefore, carbon/glass hybridization can introduce plastic deformation by increasing the percent elongation (pseudo ductility) in the CFRPC composites and suppress their catastrophic failure mode. [22,23] Over the years, pseudo ductile hybrid composites with two different types of fibers have been achieved in three distinct ways: (1) interlayer, (2) intralayer and (3) fiber-by-fiber or intrayarn configurations. [24] A number of studies have been reported over the years to achieve pseudo ductility in FRPCs.…”