DYNAMIC FORCE ANALYSIS OF N-DF MULTILOOP COMPLEX SPATIAL MECHANISMS

This paper presents the dynamic force analysis of the multiloop complex spatial mechanism with n-d.f. An equivalent hypothetical mechanism is used to analyze and solve the six-dimensional inertia forces at first, and further to get all input torques including the hypothetical inputs. A concept of local equivalent moments is introduced. Using the local equivalent moments and the first-order kinematic influence coefficients, the crucial constraint forces of the end pair of each branch connected to the centric polygon are obtained. Thereby the total mechanism can be solved. Because all the calculations contain only the multiplications and/or reversion of six or three-order matrices, the tedious calculations of more than a hundred simultaneous equations are avoided. A numerical example, a 4-d.f. six-branch mechanism, is given at the end of this paper.