Abstract
This paper discusses the application of snap-fit features to composite parts in the underhood environment. Snap-fit design for underhood applications is challenging for several reasons.
Thermal creep affects the positioning of parts relative to each other and makes the nesting of parts more difficult. Furthermore, the low allowable strains and high modulus in highly filled polymers make the use of snap-fit features difficult. Using conventional snap-fit topologies and attachment strategies limits the applicability of snap-fits to underhood components.
The importance of snap-fit topology is demonstrated via several examples that are uniquely suited to high modulus materials. The use of these features, which require only a small amount of deformation during assembly, is compared to conventional snap-fits. This paper also presents several design strategies for applying snap-fits to these difficult applications. For example, a nesting approach in conjunction with compound assembly motions produces high performance snap-fit assemblies. An example of the push & twist strategy is shown and is compared to more conventional assembly strategies.