Capacities of Z‐pinning in Improving the Bending Performance of Composite T‐joints

The capacities of Z-pinning in improving the bending performance of composite T-joints were examined experimentally and numerically. It was found that Z-pinning was not effective in enhancing the maximum bending load capacities of the T-joints. Delamination at the interfaces of flange/filler, flange/flange, flange/skin, in the arc-flange, as well as the fracture of the upper corner of the filler was observed. Among those failure patterns, the notorious delamination formed in the arc-flange assumed the main responsibility of the disability of Z-pinning in enhancing the maximum bending load capacity. Despite this, Z-pinning was found to be highly effective in improving the residual plateau load-carrying capacities of the T-joints and the maximum bending displacement could also be dramatically increased, making the T-joint maintain considerable bending load capacity under large deformation and preventing the T-joint from catastrophe failure once the maximum bending load was attained.