Damage Parameters of Adhesive Joints with General Triaxiality, Part 2: Scarf Joint Analysis

Abstract

Based on the finite element results presented in part 1 of this paper, scarf joint was chosen for further experimental investigation in order to investigate triaxiality as a function of bondline angle. At laboratory scale, scarf joints can be manufactured relatively easy due to their simple geometry. In part 2 of this paper, scarf joints as well as additional jig/fixture were manufactured. The jig/fixture were used to hold the joint during heating process and to grip it during testing. Several low cycle fatigue data have been produced as a function of bondline angle. Damage evolution was measured from the reduction of stresses in displacement controlled fatigue tests. The damage parameters, namely A and β, which are required to describe the damage evolution in the scarf joint, were determined. These damage parameters were functions of the stress level and the triaxiality function. Following on, several damage evolution relationships, i.e. a damage equation for each combination of stress/triaxiality, have been derived. It was found that the highest level of damage occurred at locations where the combinations of von Mises stress and triaxiality function have their maximum values.

Keywords:

• GENERAL TRIAXIALITY
• SCARF JOINT
• DAMAGE EVOLUTION
• CONTINUUM DAMAGE MECHANICS
• FATIGUE EXPERIMENTS