In the present paper it is introduced the method for determining the reactions of mechanical constraints ( holonomic and nonholonomic constraints). | Vietnam Journal of Mechanics, VAST, Vol. 28, No. 1 (2005), pp. 35 - 42 A NEW METHOD FOR DETERMINING THE REACTIONS OF MECHANICAL CONSTRAINTS Do SANH, Do DANG KHOA Hanoi University of Technology Abstract. In the present paper it is introduced the method for determining the reactions of mechanical constraints ( holonomic and nonholonomic constraints). As is known, for studying dynamical characters of a mechanical system it is necessary to determine the constraint reactions acting on the system. Up to now, the reactions are calculated through Lagrange's multipliers. By such a way the reactions are determined only indirectly. In the [ 3, 4 ], two methods of determining directly the reactions are discussed. However, for applying these methods, it is necessary to compute the inverse matrix of the matrix of inertia. This thing in general is not convenient, specially when the matrix of inertial is of large size and dense. In the present paper it is represented the method for determining the constraint reactions, by which it is possible to avoid inertia the computation of the inverse matrix of the matrix of inertia is avoided. For this in the paper it is used the middle variables by which we obtain a closed set of algebraic equations for directly determining reactions. 1. INTRODUCTION I:-:. the development of technics the completed systems are very interested. In accor>.:.·: e with this, the dynamic study of constrained systems is becoming more and more _:-::.-:.:-:am . .-\s is known, up to now there is not yet a general method for determining directly · _::_. ;. :-.:-.: of constraints. There is only the method of Lagrange's multipliers, by which · ::."'" :-.:-::.crions are determined through Lagrange's multipliers [ 2, 7 J. Besides this, there '.:'"' :"7'.-,::. of methods of calculating the reactions, which are discussed in the works[ 3, 4 ]. :: : -:::.:-·.-.:-:-. in order to apply the last methods, it is necessary to compute the inverse matrix : : :'.:.-:- .
