Detailed design process and assembly considerations for snap-fit joints using additive manufacturing

Abstract

The use of additive manufacturing (AM) technology has been widely adopted due to the facility to produce highly complex elements compared to conventional fabrication processes. Additionally, AM technology is rapidly developing straightforward systems enabling designers to make products faster, despite current technology limitations (i.e. processing defects, materials properties, etc.). However, not only AM technology or products must be analyzed to have concrete solutions to all existing limitations. This means, it is necessary to take into account AM design process to propose simpler solutions. Elements manufactured by AM technology have dimension limitations on build size regarding printers building capabilities, especially when the elements are more volumetric than the building chamber. In those cases, AM design process takes a significant role and a potential solution is to divide big elements in sections, which are later 3D-printed and joined using snap-fits, as the cheapest and fastest connectors available. Thus, the present work explores the detail design stages of a proposed design methodology for elements´ coupling by snap-fit joints using AM technology. The design methodology is tested on the assembly of parts from a 1-gallon plastic container. A finite element simulation for the parts coupling scenarios is presented and the effects of part’s deflection on the detail design stages are analyzed. In addition, a final design validation regarding assembly ergonomics and retention forces are discussed in order to avoid part decoupling problems or material failure.