Low-cycle Fatigue of Self-tapping Screws

Self-tapping screws (STS) exhibit high strength and stiffness if they transfer loads only by tension. That is why screws are preferably inclined with reference to the axes of the member to be connected. Nevertheless, screws might also be used as shear-loaded fasteners, which simplifies the application and increases the deformation capacity. Shear-loaded connectors are typically stressed with tension with increasing slip and the so-called ‘rope effect’ increases the shear capacity considerably. Tension stresses in the connector due to the rope effect are usually neglected in the design of the screws themselves.