Rigid Body Equilibrium Review PDF

Rigid body Statics deals primarily with the calculation of external forces which act on rigid bodies in equilibrium. Rigid Body is a combination of large number of particles occupying fixed positions with respect to each other. Conditions of rigid-body equilibrium Concurrent forces We considered f...

Rigid body Statics deals primarily with the calculation of external forces which act on rigid bodies in equilibrium. Rigid Body is a combination of large number of particles occupying fixed positions with respect to each other. Conditions of rigid-body equilibrium Concurrent forces We considered forces acting on a particle (Concurrent forces). We also considered cases where forces are not Concurrent so we are also concerned that the rigid body does not rotate. In order for a rigid body to be in a equilibrium, the net force as well as the net moment about any arbitrary point O mist be equal to zero. Support Reactions If a support prevents the translation of a body in a given direction, then a force is developed on the body in that direction. If rotation is prevented, a couple moment is extered on the body. Cables - No. Of unknown: 1 Contacting Surface - No. Of Unknown: 1 Roller Support - No. Of Unknown: 1 Pin Support - No. Of Unknown : 2 Slider or Constrained Pin - No. Of Unknown: 1 Fixed Support - No. Of Unknown: 3 Pin connections allow rotation. Reactions at pins are forces and not moments. Reaction and Constraints Completely Constrained - Rigid Body could not possibly move. Partially Constrained - Constraints are not sufficient to keep body from moving. Statistically Determinate - when the unknowns could be solved bt equations of equilibrium. Statistically Indeterminate - when there are more unknowns that equilibrium equations. We want our structure to be completely constrained and statistically determinate.