This paper presents the use of a genetic algorithm in conjunction with geometric nonlinear finite element analysis to optimize the fastener pattern and lug location in an eccentrically loaded multi-fastener connection. No frictional resistance to shear was included in the model, as the connection transmitted shear loads into four dowel fasteners through bearing-type contact without fastener preload. With the goal of reducing the maximum von Mises stress in the connection to improve fatigue life, the location of the lug hole and four fastener holes were optimized to achieve 55% less maximum stress than a similar optimization using the traditional instantaneous center of rotation method. Since the maximum stress concentration was located at the edge of a fastener hole where fatigue cracks could be a concern, reduction of this quantity lowers the probability of crack growth for both bearing-type and slip-resistant connections. It was also found that the location of the maximum von Mises stress concentration jumped from the fastener region to the lug as the applied force angle was decreased below 45 degrees, thus the fastener pattern could not be optimized for lower angles.
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