Pliage en porte-à-faux

(En anglais seulement) Cantilever bending (or flexure) tests characterize the behavior of a long sample (one dimension being a small fraction – a tenth – of the other two). In this particular case, an external load is applied at one end perpendicular to its longitudinal axis while the other end is fixed. This test configuration is particularly useful in evaluating the bending and deflection characteristics of materials. In this setup, instead of directly applying a force (Fz) through displacement of an indenter, the base of the sample is rotated such that the end of the sample pushes against a flat indenter (positioned at Fz). The flat indenter is connected to a load cell placed above the tip and records the force (Fz). The synchronized recording of the displacement (in degrees) and the load is used to generate a curve in the form of “force vs angular displacement”. This cantilever setup produces compressive stress in the concave side and tensile stress in the convex side of the material (during loading). Failure theoretically occurs from the top surface (in tension) where the high amount of reaction moment creates tensile failure through a crack that propagates downwards. Compared to 3-point bending tests, this cantilever configuration is valuable for samples with non-uniform cross-sections or long samples normally only gripped from one end.