Permanent magnets have become essential components in many household goods, ranging from coffee mugs with magnetic lids, to consumer electronics like laptops with detachable keyboards and tablets with smart covers that can automatically lock or unlock the tablet. Teardown of consumer electronics devices has revealed several permanent magnets – some of them used for the purpose of easily attaching accessories. In recent years, a tendency has developed of replacing mechanical screws with permanent magnets to attach electronic components.

A simple magnetic coupled device has two or more permanent magnets or permanent magnet(s) and ferrite(s) that latch together in a snapping action. Improper placement of magnets or inadequate design of magnets and surrounding components can compromise the structural integrity of the product due to excessive force when the magnets snap together and a magnetic latch is established. Permanent magnet dimensions, material properties, and an air gap between the latching objects are key factors in determining the magnetic force. Therefore, it is desirable to simulate and understand not only the magnetic forces between the permanent magnets, but also the impact these forces might have on the structure when the bodies latch together. Even though the problem statement seems straightforward, the complexity of interlinked magnetics and structural changes combined with flexible/rigid body topologies make it a challenging simulation.