Mechanical parts will produce different forms of deformation under different external forces

Reverse

This type of deformation is caused by two force couples with equal magnitude and opposite directions, and the acting surfaces are both perpendicular to the rod axis. It is manifested that any two cross-sections of the rod undergo relative rotation around the axis. The transmission shaft of the car, the main shaft of the motor and the water turbine, etc. are all torsion rods. When there is a force couple acting in a plane perpendicular to the axis of the rod, the rod will undergo torsional deformation, that is, each cross section of the rod rotates relative to the rod axis. The torsional deformation of the rod has the following characteristics: Stress: Two force couples are acting on the plane perpendicular to the axis of the rod at both ends of the rod, the moment of the couple is equal, and the rotation direction is opposite. Deformation: Each cross-section on the rod rotates relative to the axis of the rod. The relative rotation angle between any two cross-sections is called the relative torsion angle. Torsional deformed components are often encountered in engineering. For example, the two hands of the driver apply a force of equal magnitude, opposite directions, and parallel lines of action on the plane of the steering wheel. They form a force couple and act on the end of the joystick, while the end of the joystick is affected by the force from the steering gear. The action of the anti-couple, so that the joystick is subjected to torsion.

To bend

This type of deformation is caused by a transverse force perpendicular to the axis of the rod, or by a pair of equal and opposite force couples acting in the longitudinal plane containing the axis of the rod, and the axis of the rod changes from a straight line to a curve. In engineering, bending members are one of the most frequently encountered situations. The deformation of the girder of the bridge crane, various mandrels and turning tools, etc., all belong to bending deformation. After being stressed, the axes of these straight rods will bend from the original straight line to a curve, and this deformation is called bending. Members with predominant bending deformation are often called beams. There are also some rods that undergo several basic deformations at the same time. For example, the three basic deformations of bending, torsion and compression occur when the spindle of a lathe is working; This situation is called combined deformation.