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THIS presentation on fastening of composite structures includes material characteristics, hole generation parameters and methods, types of fasteners available and automation equipment and approaches.

D. Electrical Continuity and Lightening Strike Protection In metallic structure aircraft, much of the structure is often interconnected electrically via special grounding straps. One would think the grounding would be accomplished automatically via the aluminum rivets or titanium fasteners in the structure. Aluminum rivets, however, are anodized for corrosion protection and titanium fasteners are often coated with an aluminized paint as a barrier protection against galvanic corrosion of the structure. Both of these coatings are non‐conductive and other means such as periodic cadmium plated stainless steel fasteners or grounding straps are used. But why all the concern about electrical continuity? The reason is to avoid large differentials in electric potential between components when lightening strikes an airplane. If there is a large difference because there is no conductive flow path, the electricity will arc to the lower potential member and cause damage in the process. If this occurs within a fuel tank it could be catastrophic. Once the structure all has the same charge it proceeds to dissipate the charge back into the atmosphere.

Aerospace assembly demands high drilling position accuracy for fastener holes. Hole position error correction is a key issue to meet the required hole position accuracy. This paper aims to propose a combined hole position error correction method to achieve high positioning accuracy.

The bilinear interpolation surface function based on the shape of the aerospace structure is capable of dealing with position error of non-gravity deformation. A gravity deformation model is developed based on mechanics theory to efficiently correct deformation error caused by gravity. Moreover, three solution strategies of the average, least-squares and genetic optimization algorithms are used to solve the coefficients in the gravity deformation model to further improve position accuracy and efficiency.

Experimental validation shows that the combined position error correction method proposed in this paper significantly reduces the position errors of fastener holes from 1.106 to 0.123 mm. The total position error is reduced by 43.49% compared with the traditional mechanics theory method.

The position error correlation method could reach an accuracy of millimeter or submillimeter scale, which may not satisfy higher precision.

The proposed position error correction method has been integrated into the automatic drilling machine to ensure the drilling position accuracy.

The proposed position error method could promote the wide application of automatic drilling and riveting machining system in aerospace industry.

A combined position error correction method and the complete roadmap for error compensation are proposed. The position accuracy of fastener holes is reduced stably below 0.2 mm, which can fulfill the requirements of aero-structural assembly.

The purpose of this paper is to present a review about sizing of joints, from the static and fatigue points of view. A discussion about advantages and disadvantages of each joining technology, among the ones mentioned above, will be presented.

Although many other aspects will be discussed, emphasis will be given to the joint fatigue behavior, and fatigue test results will be presented and discussed.

This paper is a subject review, where no new findings are presented. However, the comparison of fatigue test results for mechanically fastened joints and friction stir welding joints will show the advantages of the latter.

With the information presented, the authors expect to provide some guidelines that will help to improve future joint designs.

The review information contained in this paper may be used as reference for aircraft joint design.

THE increasingly important role of high‐modulus, fiber‐reinforced, epoxy‐resin composites in aerospace applications highlights the need for fasteners designed specifically for the materials. Strong as the composites are, they can be easily damaged by a fastener that would give excellent service when joining metals. A second limitation on the use of metal fasteners with advanced composites is the fact that certain metals commonly used for high‐strength fasteners can experience galvanic corrosion in composites containing graphite or carbon fibers.

A dedicated eddy current instrument, introduced by Staveley NDT Technologies is used to find flaws in aircraft fastener holes with the fastener remaining in place.

Workable application of an emerging technology requires that the impact of that technology be assessed within its operating arena.

The purpose of this paper is to introduce a closed-form analytical solution to evaluate the nominal moment capacity and associated deflections of steel-FRP beam systems. The proposed solution takes into consideration the partial composite behavior resulting from the interfacial contact and slip between the subcomponents of the system.

The partial composite action theory was used to develop an elastic analytical solution for the deflection of simply supported composite steel-FRP beams subjected to a mid-span point load. The solution takes into consideration the partial composite behavior of the system that arises from the interlayer slip at the steel-FRP interface.

The developed analytical model is used to predict the nominal moment capacity of the composite beam and the load value at the onset of yielding in the steel subcomponent of the section. The distribution of shear forces induced in the steel fasteners due to the interfacial slip is also obtained analytically. A comparative study is conducted by comparing the analytical results to their counterparts resulting from finite element modeling of the composite steel-FRP system. The agreement between analytical results and finite element predictions validates the accuracy of the derived analytical solution for partial composite steel-FRP beams.

The proposed solution applies only to the FRP strips and 6 mm steel bolts used in the study.

Recent studies revealed a promising efficiency of using mechanically fastened hybrid FRP sheets in strengthening steel beams. A major advantage of this technique is the ductile behavior of the steel-FRP system. The current paper introduces a closed-form analytical solution to evaluate the nominal moment capacity and associated deflections of steel-FRP beam systems. Forces developed at the steel-FRP interface due to the relative slip between both components are considered in the proposed analytical solution.

Fan blades made of layers of graphite/epoxy coated with titanium reportedly enable the GE90 gas turbine engine from General Electric Aircraft Engines, Cincinnati, Ohio, to deliver more power while using less fuel and reducing pollution. The GE90 will power the new Boeing 777 widebody aircraft.

The continuous need for agility coupled with increasing labour costs and improvements in reliability and capability of automation has meant a renewed interest in the application of robots to many manufacturing activities. Research at the University of the West of England, Bristol has focused on the design of an integrated, modular system for the assembly of large products. The work under the ALASCA project has resulted in a number of technologies that will significantly affect assembly automation. The paper discusses the latest results from this work and presents the experimental conclusions thus far.