Anchor escapement clockmaker George Graham around 1715. This gradually superseded the recoil escapement and is used in virtually all modern pendulum clocks with anchor escapements. The anchor escapement consists of two parts: the "escape wheel", which is a vertical wheel with pointed teeth on it rather like saw teeth, and the "anchor", shaped vaguely like a ship's anchor, which swings back and forth on a pivot just above the escape wheel. On the two arms of the anchor are curved and flat faces which the teeth of the escape wheel push against, called "pallets". The central shaft of the anchor is attached
Strain energy release rate Strain energy release rate The strain energy release rate (or simply energy release rate) is the energy dissipated during fracture per unit of newly created fracture surface area. This quantity is central to fracture mechanics because the energy that must be supplied to a crack tip for it to grow must be balanced by the amount of energy dissipated due to the formation of new surfaces and other dissipative processes such as plasticity. For the purposes of calculation, the energy release rate is defined as where formula_2 is the potential energy available for crack growth, formula_3 is the work associated