Design for Static and Dynamic Loading

Design for Static and Dynamic Loading

Machine parts fail when the stresses induced by external forces exceed their strength. The external loads cause internal stresses in the elements and the component size depends on the stresses developed.

Loading may be due to:

• The energy transmitted by a machine element.
• Dead weight.
• Inertial forces.
• Thermal loading.
• Frictional forces.

Load may be classified as:

• Static load- Load does not change in magnitude and direction and normally increases gradually to a steady value.

• Dynamic load- Load may change in magnitude for example, traffic of varying weight passing a bridge. Load may change in direction, for example, load on piston rod of a double acting cylinder. Vibration and shock are types of dynamic loading.