The Theory of Critical Distances for Predicting the Static Failure of Double‐Lap Bolted Joints With Conventional and Additively Manufactured 316L Stainless Steel Inner Plates

ABSTRACT This study assesses the accuracy of the theory of critical distances applied in the form of the point method in predicting the static strength of 316L stainless steel double‐lap shear bolted connections under static tensile loading. Single‐ and double‐bolt configurations were tested using inner plates manufactured from conventional material and from additively manufactured material, namely wire arc additive manufacturing and selective laser melting. The additively manufactured plates were assessed in both machined and as‐built conditions and extracted at different printing orientations. Treating the bolt hole as a stress concentrator, linear elastic finite element stress fields were postprocessed to determine the point method effective stress from stress–distance curves extracted along different paths relative to the loading direction. The point method, calibrated using an inherent stress and a characteristic length estimated from 2‐mm‐thick conventional notched plates, provided generally good predictions for both conventional and additively manufactured plates. However, the prediction accuracy decreased for thicker as‐built wire arc additively manufactured plates. Recalibrating the point method using wire arc additive manufacturing notched specimens with a comparable mean thickness improved the predictions for the thicker wire arc additively manufactured plates; however, a nonconservative bias remained. These findings confirm that the point method parameters calibrated using plain and notched specimens can be transferred to bolted joint assemblies.