Mitigating the Effects of Local Flexibility at the Built-In Ends of Cantilever Beams

Abstract

Local distortion at the built-in ends of cantilever beams can lead to significant errors when models assume the support to be perfectly rigid. This paper presents a novel approach for mitigating this effect, using appropriately sized fillets to provide the additional stiffness needed to make simplified models more accurate and reduce stress concentrations. The optimal nondimensional fillet radius, called the optimal fillet ratio, is shown to be nearly constant for a wide range of geometries under predominantly bending loads, making it a useful parameter in the design of planar monolithic flexible mechanisms.