The Influence of Interface Specifications on In- and Out-of-plane Loaded Hybrid Joints

Description

Metal inserts are a common approach to establish connection points for carbon fibre reinforced polymer (CFRP) components. The classic design has drawbacks regarding weight and induces stress concentrations at the interface between insert and CFRP laminate due to stiffness discontinuities. In this paper a new biomimetic inspired geometry for inserts with three different interface specifications is presented. The additively manufactured titanium alloy Ti6Al4V part is realised in plain configuration, with lattice structure, and with lattice structure and pins, and is bonded to a CFRP laminate. Specimens for two different load cases – lap shear specimens for in-plane and peeling specimens for out-of-plane loading – are manufactured and tested on a hydraulic test rig. Beside the load and displacement measurements, additionally, the surface displacement of the out-of-plane loaded specimen is evaluated using three-dimensional digital image correlation. For lap shear specimens predominantly shear and for peeling specimens predominantly normal stress is responsible for failure. The interface specification does not change the stiffness of the lap shear hybrid joint significantly. However, the total failure load changes considerably with lattice structure and pins yielding the highest strength. Similar observations regarding the total failure load are made at the peeling tests. Especially, the protruding pins lead to a damage tolerant hybrid joint. Compared to the other specifications, local damages at the pinned design only marginally influence the surface deformations in other areas.

Period	01 Aug 2023
Event title	23rd International Conference on Composite Materials
Event type	Conference
Location	United KingdomShow on map