Student Profile

Senior Project Profile: Dennis Zhang

“Bone-inspired foam beams”

Dennis Zhang, S.B. ’18, mechanical engineering

Advisor: Joost Vlassak, Abbott and James Lawrence Professor of Materials Engineering

On an airplane, every pound of weight counts. Zhang focused his project on the foam beams used in aircraft, applying a novel manufacturing technique in an effort to produce beams that are more weight-efficient. He was inspired by the structure of bones, which are naturally dense around the exterior and spongy in the middle. He applied the same mindset to foam beams, using a polyurethane foam that expands and solidifies into a rigid material, leading to a beam with an exterior density that is greater than its interior density. He studied how to effectively create a beam that balanced durability with lightweight structure, using a centrifuge to compress the cells inside the foam and increase density, before pre-curing the foam prior to molding to increase the exterior-to-interior density ratio. Zhang’s method was able to increase the strength over similar foam beams by 8.3 percent.

“My goal was to develop a novel manufacturing method for creating structural foam beams that are more weight-efficient than traditionally-manufactured foam beams, with potential aerospace applications,” he said. “Since weight is so costly to airlines, the ability to create beams that are significantly lighter without compromising structural integrity could lead to large savings in both money and environmental impact. Weight is even more costly for spaceflight; as space exploration regains popularity, it's possible that this technology could be applied to those fields as well.”