The influence of the hole-generation process on fatigue response of open-hole and assembled titanium samples

The holes required for a bolted connection can be produced in several ways. The defects around the hole and the hole surface finish influence the fatigue life of the produced part. Abrasive waterjet cutting is compared with conventional drilling to assess these influences on titanium alloy parts. Open-hole tensile tests show a preferential fatigue behavior for conventionally drilled samples because of the lower roughness. The originality of this work focuses on linking the surface texture and damage to the life expectancy of the open-hole samples and determining the failure steps/modes of the assembled samples. A model is proposed to track the crack progression that offers adequate life estimations for open-hole samples. Single-shear assembly bearing tests show no difference between the drilling processes, and failure is obtained by secondary bending for both drilling methods.