Ideal constraint can be divided into complete ideal constraint or incomplete ideal constraint according as generalized ideal constraint forces equal to zero or not.

Ideal constraint can be divided into complete ideal constraint or incomplete ideal constraint according as generalized ideal constraint forces equal to zero or not.

Based on D′Alembert′s principle in generalized forces, Appell′s universal equation of dynamics with non embedding constraint containing generalized incomplete ideal constraining force is established, not having to consider the restriction of placing constraints on virtual displacement.

The conservation law of mechanical energy in variable mass mechanical systems with ideal bilateral holonomic constraints is studied.

In general mechanical documents, the exposition of the basic types of ideal constraints is incomplete, and even inaccurate.

By means of the fractions of the equation of the non一ideal constrained motion of the particle along the plane curve on the tangential direction and normal direction,the motion speed expression of the particle under this condition is derived,the constrained counter force is further gained,thus some non一ideal constraint problems are solved from the given angle.

Ideal constraint can be divided into complete ideal constraint or incomplete ideal constraint according as generalized ideal constraint forces equal to zero or not.