Additively Manufactured Deltoid Fillers for Composite T-joints


Additively Manufactured Deltoid Fillers for Composite T-joints



Khalid Aldhahri


Presentation: 11:40 a.m.-12:00 p.m., Science Center 146



Advanced composite materials consist of continuous fibers of carbon or glass embedded in a polymer matrix, such as epoxy. This hybrid material system forms a high-strength and lightweight structure that is increasingly used in a wide variety of applications, including aerospace, marine structure and vehicles, energy production, sporting goods, and general infrastructure. There are numerous manufacturing processes for making these products, but all of them involve combining the matrix with a high concentration of reinforcing fibers, resulting in a highly compacted laminate structure. T-joint composite parts have been widely used in the construction of products in several applications, especially in aerospace. Recently, there has been increased interest in investigating T-joint strength behavior and failure mechanisms through a combination of experimental and numerical approaches. These parts require a filler material in the voided deltoid region, where the base and flange meet, to ensure their strength and damage tolerance. To provide structural integrity, including a filler material in the deltoid region is necessary for finished composite parts. Conventionally, the deltoid region fills up with resin during molding, or a rolled-up piece of fabric is placed in the region prior to molding to reinforce the resin. Neither approach is ideal for several reasons including fiber distortion and uncontrolled permeability in the deltoid region. In this research, a tensile pull-off test is used to investigate the strength of T-joint parts with different custom porosity of 3D printed parts used as the filler material. The maximum force required to fail the structure, as well as the total elongation to failure, were compared for a carbon/epoxy composite T-joint structure.

Publication Date


Project Designation

Graduate Research

Primary Advisor

Donald Klosterman

Primary Advisor's Department

Chemical and Materials Engineering


Stander Symposium, School of Engineering

Additively Manufactured Deltoid Fillers for Composite T-joints