Title: Dynamic Crush Response of Bilayer Glass Foam Structures with Tailorable Architectures

Authors: Sri Suhas Chokkaku, Jungjin Park, Norman Wereley

DOI:

Abstract: Dry Powder Printing (DPP) is an additive manufacturing technique that uses controlled vibration and nozzle dispensing to deposit dry powders—such as hollow glass microspheres (HGMs)— into molds without liquid binders. Using this approach, HGMs of varying densities can be precisely layered and subsequently consolidated through sintering to create porous structures with tunable density, resulting in a tailorable mechanical response. The method is particularly well-suited for producing multilayer architectures, as it yields uniform interfaces between layers and allows for tailoring of stress-strain behavior through careful selection of HGM feedstocks and layer thickness ratios. Previous work demonstrated that bilayer glass foams fabricated using DPP exhibited distinctive two-step plateau stress under quasi-static compression. By varying the density and relative thickness of the layers, the onset of the second plateau could be tuned, thereby enabling control over energy absorption profiles. Importantly, this bilayer strategy also reduced peak stresses, which are critical for mitigating pedestrian injury and other impactsensitive scenarios, while maintaining high levels of energy dissipation. In the present study, these findings were extended to dynamic impact conditions. Bilayer glass foam cylinder samples were fabricated with the top half composed of iM16K HGMs and the bottom half composed of S32HS HGMs. At an increased speed of 5 m/s—representative of more realistic crash conditions—the bilayer samples exhibited substantially greater crush ratios and energy absorption. The iM16K/S32HS bilayers achieved values of 1.80 MJ/m3. These results highlight the capability of bilayer architectures to simultaneously mitigate peak forces and deliver enhanced energy absorption under dynamic loading. Overall, the results demonstrate that DPP enables the design and fabrication of multilayer glass foams with tailored mechanical responses. By strategically combining HGMs of different densities, it is possible to reduce peak stresses while achieving high energy absorption, offering lightweight, impact-mitigating materials in applications such as automotive crash safety and protective structural components.

References: 1. Liu, W.; Su, S.; Qiu J.; Zhang, Y.; Yin, Z. “Exploration of Pedestrian Head Injuries— Collision Parameter Relationships through a Combination of Retrospective Analysis and Finite Element Method.” International Journal of Environmental Research and Public Health, Vol. 13, No. 12, 2016, Article 1250. https://doi.org/10.3390/ijerph13121250 2. Park, J.; Howard, J.; Edery, A.; DeMay, M.; Wereley, N. “Tunable Energy Absorbing Property of Bilayer Amorphous Glass Foam via Dry Powder Printing.” Materials, Vol. 15, No.24, 2022, Article 9080. https://doi.org/10.3390/ma15249080 3. Park, J.; Howard, J.; Edery, A; DeMay, M.; Wereley, N. “Bilayer Glass Foams with Tunable Energy Absorption via Localized Void Clusters.” Advanced Engineering Materials, Vol. 23, No. 9, 2021, Article 2100205. https://doi.org/10.1002/adem.202100105 4. Ghosh, D.; Wiest A.; Conner R.D. “Uniaxial Quasistatic and Dynamic Compressive Response of Foams Made from Hollow Glass Microspheres.” Journal of the European Ceramic Society, Vol. 36, No. 3, 2016, pp. 781-789. https://doi.org/10.1016/j.jeurceramsoc.2015.10.018 5. Rahman, O.; Uddin, K.Z.; Muthulingam. J.; Youssef, G.; Shen, C.; Koohbor, B. “DensityGraded Cellular Solids: Mechanics, Fabrication, and Applications.” Advanced Engineering Materials, Vol. 24, 2022, Article 2100646. https://par.nsf.gov/servlets/purl/10344442 6. Fiedler, T.; Movahedi, N.; York, L.; Broxtermann, S. “Functionally-Graded Metallic Syntactic Foams Produced via Pre-Compaction.” Metals, Vol. 10, No. 3, 2020, Article 314. https://doi.org/10.3390/met10030314 7. He, S.; Lv, Y.; Chen, S.; Dai, G.; Liu, J.; Huo, M. “Gradient Regulation and Compressive Properties of Density-Graded Aluminum Foam.” Materials Science and Engineering: A, Vol. 772, 2020, Article 138658. https://doi.org/10.1016/j.msea.2019.138658

Conference: SAMPE 2026

Publication Date: 2026/04/27

SKU: 39

Pages: 14

Price: $28.00