Design of heat-activated reversible integral attachments for product-embedded disassembly

Disassembly is a fundamental process needed for component reuse and material recycling in all assembled products. Integral attachments, also known as "snap" fits, are favored fastening means in design for assembly (DFA) methodologies, but are not necessarily a favored choice for design for disassembly. Several prototype designs of a new class of integral attachments are presented, where the snapped joints can be disengaged by the application of localized heat sources. The design problem of reversible integral attachments is posed as the optimization of compliant mechanisms actuated with localized thermal expansion of materials. The Homogenization Design Method is utilized to obtain an optimal structural topology that realizes a desired deformation of snapped features for joint release. The obtained optimal topologies are simplified to enhance the manufacturability for the conventional injection molding technologies. Results of the example designs are verified by finite element analyses