ANALYSIS OF MULTIFASTENER COMPOSITE JOINTS

A new numerical procedure for determining load proportioning in multif astener mechanical joints in composite plates is presented. The joints are loaded in double lap fashion in tension with pins through the hol es. The commercial finite element program ABAQUS is used to predict th e load proportioning among fasteners using two independent plane stres s finite element models, one representing the composite inner lap and one representing the two steel outer laps, interacting through rigid c ircular surfaces. The circular surfaces effectively represent rigid pi ns. Load proportioning is predicted for a number of geometries. Excell ent correlation with experimental data is obtained. Experimental and c omputed surface strains are aw found to compare well. The assumption o f a radial cosine distribution of contact stress between fastener and hole boundary, often used in these studies, is shown to be substantial ly in error for some holes.