A new graphical technique for acceleration analysis of four bar mechanisms using the instantaneous center of zero acceleration

In this work, a new graphical technique is furnished for acceleration analysis of four bar mechanisms through locating the instantaneous center of zero acceleration $$IC_{a}$$ICa of the coupler link. First, the paper observes the coupler’s $$IC_{a}$$ICa locus and then proceeds with a series of graphical constructions that eventually lead into locating the $$IC_{a}$$ICa and obtaining the linear/angular accelerations of the coupler and follower (or slider) links. Based on the proposed graphical technique, the ease of acceleration analysis for four-bar mechanisms with varying driver’s angular acceleration is demonstrated. Simultaneously, the inflection circle of the coupler curve is constructed without the need to apply Euler-Savary equations. With fewer constructions than classical graphical techniques, the robustness and simplicity of the proposed method are demonstrated by performing acceleration analysis of a slider-crank (RRRP) and a planar quadrilateral linkage (RRRR).