Abstract
This paper presents a method for predicting fatigue crack propagation in single lap adhesively bonded composite joints with an initial full-width pre-existing disbond using finite element analysis and numerical integration of the fatigue crack growth rate law. Fatigue tests were conducted on the single lap joints to monitor crack lengths from four runout corners. A novel in-situ crack growth measurement technique has been developed using red ink injection through a needle nozzle through the interface over the lap in order to identify the crack propagation profile during tensile-tensile fatigue loading. The crack growth was modelled using a fracture mechanics criterion under quasi-static conditions in finite element analysis. Two model assumptions were made considering the crack length from one runout end alone, and under the influence of crack length from the other runout end occurring due to fatigue load. The crack growth rate law was determined experimentally using the standard double cantilever beam (DCB), mixed mode bending (MMB) and end notch flexure (ENF) specimens. The numerical models based on the crack propagation in the adherend-adhesive interface and crack growth rate data from mixed mode tests, allowed for predicting the lower and upper bounds of the fatigue crack growth rate of the single lap joints, observed during fatigue tests with good accuracy.
| Original language | English |
|---|---|
| Pages (from-to) | 164-172 |
| Number of pages | 7 |
| Journal | International Journal of Adhesion and Adhesives |
| Volume | 87 |
| Early online date | 9 Oct 2018 |
| DOIs | |
| Publication status | Published - Dec 2018 |
Keywords
- single lap joints
- adhesive bond
- finite element analysis
- fatigue crack growth rate
- fatigue life prediction