Abstract:

ESDU Fat A.05.02 gives a method of estimating the endurance of pin joints from fatigue data on other types of specimen. From the results of photoelastic tests, curves are given that allow the maximum shear stress on a transverse diameter of the hole with interference to be found. It is given as a function of the maximum shear stress on a transverse diameter due to interference alone which can be found from ESDU 71011. The equivalent loading cycle yielding the same maximum shear stress on either a plain or notched specimen can then be determined and fatigue data from such test pieces used to estimate the fatigue behaviour of the joint. Alternatively, the equivalent loading cycle on a joint with push-fit pins can be calculated and data from ESDU 80007 used to evaluate the fatigue behaviour of the joint. Maximum shear stress is used because under combined stress systems (in this case resulting from the interference) it determines the fatigue behaviour. A worked example shows how the method is applied to a two pin joint.