Concept and Objectives:

The main challenge of the BOPACS project is to reduce the weight and costs of primary aerospace structures by developing bolt free adhesive bonded joints that comply with the airworthiness requirements.

Until today thin walled composite primary aerospace structures are joined by using a large number of fasteners. Bolt free joining would considerably contribute to the weight and cost reduction of aerospace structures.

Within BOPACS target applications will be selected that are commonly used in today’s aerospace primary structures and where adhesive bonding might advantageously replace conventional riveting / fastening. Based on these target application bolt free adhesive bonded joining methods will be developed that comply with the EASA airworthiness requirements.

Contrary to projects focusing on the development of non-destructive techniques for the inspection of weak bonds, BOPACS proposes arigorous road map to certification by developing Means of Comply based on:

  • Thorough research, beyond the state of the art, into the crack growth / disbond extension mechanisms in adhesively bonded joints.
  • Design, analysis, testing and assessment of different categories of crack stopping design features, i.e. features that are capable of preventingcracks or disbonds from growing above a predefined acceptable size, with a joint still capable of carrying the limit load.

The project results and certification issues will be reviewed on a regular base by EASA representatives through the Airbus certification department.

Public Documents

Periodic Report Summary


Fatigue behaviour and damage tolerant design of composite bonded joints for aerospace application
Kruse, T. Körwien and R. Ruzek

Numerical simulation of fatigue crack growth in the adhesive bondline of hybrid CFRP joints
Sachse, A.K. Pickett, M. Käß, P. Middendorf

A Hybrid Bondline Concept for Bonded Composite Joints
Löbel, D. Holzhuter, M. Sinapius, C. Huhne

Experimental investigation of mechanical fasteners regarding their influence on crack growth in adhesively bonded CRFP-joints subjected to fatigue Loading
Sachse, A.K. Pickett, W. Adebahr, M. Klein, M. Käß, P. Middendorf

Bonding of cfrp primary aerospace structures – crackstopping in composite bonded joints under fatigue
Kruse, Dr. T. Körwien, S. Heckner and Dr. M. Geistbeck

Mode-I, mode-II and mixed-mode I+II fracture behavior of composite bonded joints: Experimental characterization and numerical simulation
Floros, K.I. Tserpes, and T. Löbel