IHS ESDU Fatigue of bolted steel lap joints and doublers. 96014

ESDU 96014 presents data relating to joints fabricated from seven different structural steels with tensile strengths ranging from 400 to 867 MN/sq m (58E3 to 126E3 lbf/sq ft) secured, with the exception of one group of joints, with either ASTM A325 or A490 bolts. The joints were double lap joints with 2, 3, 4, 6 or 10 bolts and a double cover plate butt joint with two bolts. Some data are also given for doublers, that is a configuration similar to a double cover plate butt joint in which the plate is continuous. Fatigue data for 39 different joints are presented as plots of the ratio of alternating stress on the gross section of the joint or doubler to the tensile strength of the material against cycles to failure. Each plot is accompanied by a dimensioned sketch of the joint and a table giving details of the test specimen and conditions. Comparable data for plain plates and plates with holes are given when available. The effects of the following factors are assessed: the number of bolts and the clamping pressure, the tensile strength of the joint material, the bolt arrangement, the bolt tightening procedure, the condition of the contacting surfaces, the stress ratio, the cover and centre plate thicknesses, and the joint width.