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 This gradually superseded the recoil escapement and is used in virtually all modern pendulum clocks with anchor escapements.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 a straight path, the mode I stress intensity factor (formula_10) is related to the energy release rate (formula_5) by where formula_13 is the Young's modulus and formula_14 for plane stress (as in a thin tensed elastic sheet) and formula_15 for plane strain (as in a thick elastic slab). Therefore, the energy release rate failure criterion may also be expressed as where formula_17 is the mode I fracture toughness. 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