Experimental evaluation of laminated glass interlayer under high strain rates

Abstract

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] The use of blast-resistant glazing in buildings subject to exterior hazards can greatly reduce, if not eliminate, the hazard of flying glass shards. When properly designed, framed, and anchored, blast resistant laminates are capable of maintaining the integrity of the building envelope following an explosion or a hurricane and reducing interior damage. Analytical and experimental research exists in the literature in the area of blast-resistant glazing, but few areas of research remain unexplored related to resistance and blast response of the window system. The material response of the laminated glass under high strain rates has not been fully investigated. Therefore, the main objective of this research is to experimentally evaluate the high strain rate effects of PVB and UVEKOL-S polymers alone and laminated glass sheets using impact drop-weight testing. Virgin PVB as well as UVEKOL-S sheets extracted from laminated glass panels will evaluated in this study. The results of this study are expected to enhance the engineering design methods and numerical modeling of laminated glass windows under blast loading. A drop-weight testing apparatus was designed in this thesis for evaluating PVB and UVEKOL-S and laminated glass samples under various loading rates. Quasi-static testing of the materials was also evaluated to assess the effects of dynamic loading on the engineering response and energy-absorption capabilities of the laminated glazing and interlayer materials. The results show that the dynamic loading significantly affects the material response and the energy absorption characteristics of the interlayer materials. The strain rate variation had a more pronounced effect on the energy and impulse characteristics of the material than the ultimate strength of the polymers. Confined polymers inside scored laminated glass samples had lower dynamic strengths than polymers alone. The results of this thesis provide valuable findings regarding the dynamic response of interlayer polymers, but additional tests are still needed to develop statically reliable results. Also, a wider range of strain rates is recommended for future testing to study the effect on the glazing system under extremely high strain rates.