Experimental Study on Foam Density Influence in ۳D-Printed Foam-Filled Sandwich Beams Under Flexural Loading

The demand for lightweight structures has led to the exploration of foam filling as an effective method for enhancing flexural strength without significantly increasing weight. In this study, we developed a novel ۳D composite beam with a re-entrant anti-trichiral honeycomb core, fabricated using PLA-based ۳D printing. To investigate the effect of foam filling on flexural properties, the beams were filled with two types of polyurethane foam with densities of ۱۰۰ and ۱۳۰ kg/m³, and their flexural performance was evaluated through three-point bending tests. The results indicated that foam density plays a critical role in determining flexural performance, including flexural modulus (Ef), flexural strength (σf), energy absorption (EA), and specific energy absorption (SEA). The low-density foam resulted in an ۱۱.۹% increase in EA, ۵.۲۲% in SEA, ۳.۳۵% in Ef, and ۲۸.۹۴% in σf compared to the hollow beam. Conversely, the high-density foam showed no change in EA, a ۳.۹% decrease in SEA, but marked improvements in Ef ۹.۲۳% and σf ۷۴.۰۸% compared to the hollow sample. These findings highlight the significant impact of foam filling on the flexural modulus and load-bearing capacity of the composite beams, offering valuable insights for the design of lightweight, high-strength structures.

کلیدواژه ها:

۳D printing ، Sandwich beam ، Foam filled ، Honeycomb ، Three-point bending