Study the effects of PEG modification methods on the resistance of 3D E-glass woven-STF composites at quasi-static and low-velocity impact loads

The present study focuses on the effect of chemical modification of polyethylene glycol (PEG 400) to be used as shear thickening fluids (STF) to improve the impact strength of 3D E-Glass fabrics. The base fluid (PEG) was modified individually using citric acid (C), adipic acid (A), and hexamethylene diisocyanate (H). The Comparison of the rheological analysis revealed that the viscosity of the H-STF, A-STF, and C-STF increased by 12.73, 9.65, and 3.46 times to the pure STF, respectively while the critical shear rate decreased significantly. Notably, the chemical modification of PEG results in improved particle-media interaction by modified H-bonding. Quasi-static tests with different penetrators (spike and stab) were carried out at a crosshead speed of 100 mm/min. Low-velocity impact tests with different penetrators (spike and knife) and with different impact velocities were performed to study the energy absorption of the neat 3D glass fabrics and composites with STF matrices. A comparison of normalized energy absorption of a two-layer of A-STF/fabric, C-STF/fabric, and H-STF/fabric composites (impactor: spike, height: 950 mm) relative to conventional composite (the P-STF/fabric composite) showed an impressive increase of 39.25, 27.60, and 17.14%, respectively.