Effect of Eccentric Loading on Springs
Definition of Eccentric Load: When the load applied to a portion of the column (spring) is not symmetric with the central axis of the column (spring), the load applied is called eccentric load.
Explanation: In above figure (Diagram 1) P is applied load, L is length of the object under load. Here load P is not symmetric with the central axis of the object.
Effect of Eccentric Load on Spring: Spring is an elastic body which when subjected under any type of load starts to deform. If the applied load is in allowable physical tolerances the spring gets back to the initial position due to its elasticity.
It is very important that the applied load is not just in the given physical tolerances but, is also applied properly. If a spring is applied be load P of which the axis is not symmetric with the central axis there is a chance of spring buckling, which can lead to spring breakage.
When eccentric load acts on the spring the stresses on spring coil increases and load parameter also varies. Due to eccentric loading the stresses on the farthest side (reff. Diagram 2) increases i.e. side A. The stresses on the nearest side of eccentric load decreases due to extra compression. The effect of eccentricity on spring varies considerably with the shape of end coil and also the number of coils in the spring. Stress increase due to eccentric loading varies directly with the distance between central axis and load axis (e).