A 3D printed dual cure epoxy is evaluated as a bonding material for composite T-joint structures and compared with other traditional bonding materials by mechanical testing. The epoxy is processed in two steps. First, it is 3D printed using Digital Light Synthesis (DLS), a vat photopolymerization process, resulting in semi-rigid, but only partially cured part. This part is then integrated with pre-impregnated fiber reinforced epoxy resin sheets and co-cured in a second, thermally activated, stage.

The bonding strength of the 3D printed epoxy is first investigated by single lap-shear joints and is then implemented in the manufacturing of composite T-joints. The T-joints utilizing 3D printed epoxy as a bonding material show sufficient joint strength in tensile pull-out tests when compared to other common bonding methods. In addition, the 3D printed joints provide a highly reproducible, defect-free bond with improved geometric accuracy. This technology enables the ability to manufacture hybrid composite structures with decreased manufacturing costs due to fewer fixtures, shorter manufacturing times, and a reduction in defects. Furthermore, these adhesive parts can utilize the design freedom of 3D printing by including intricate internal geometries, such as lattice structures, textures, or channels.

3D打印的双固化环氧树脂被评估为复合T形接头结构的粘结材料，并通过机械测试与其他传统粘结材料进行了比较。环氧树脂分两个步骤进行处理。首先，使用大桶光聚合工艺通过数字光合成（DLS）将其进行3D打印，从而得到半刚性但仅部分固化的零件。然后将这部分与预浸渍的纤维增强环氧树脂片集成在一起，并在第二个热激活阶段共固化。

首先通过单搭接接头研究3D打印环氧树脂的粘合强度，然后将其用于复合T形接头的制造中。与其他常见的粘合方法相比，采用3D打印环氧树脂作为粘合材料的T型接头在拉伸试验中显示出足够的接头强度。此外，3D打印接头可提供高度可重复的无缺陷粘合，并具有改进的几何精度。由于减少了固定装置，缩短了制造时间并减少了缺陷，因此该技术能够以降低的制造成本来制造混合复合结构。此外，这些粘合部件可以通过包括复杂的内部几何形状（例如，晶格结构，纹理或通道）来利用3D打印的设计自由度。