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The distribution of loads between the components of a structural assembly depends not only on their dimensions and material properties but also on the stiffness of fasteners connecting the components. So, the accuracy of the finite element analysis is influenced much by the fastener representation in the model. This paper describes an approach designed specifically for joints with connected plates modeled by shell elements located at plates mid planes. The procedure is based on definition of independent components of a fastener joint flexibility, analysis of each component, and their assembly to represent a complete plate-fastener system of the joint. The proposed modeling technique differs from the traditional approach where all the connected plates are modeled coplanar. The traditional approach is based on calculating a single spring rate for a particular combination of fastener and plate properties.

This paper covers issues related to the installation, testing, and production implementation of a large-scale automated wing drilling/fastener installation system. Emphasis is placed on describing the production process, foundation requirements, axes alignment, calibration, testing and implementation. Description will include key hardware features such as the multi-function end effector and spindle end effector. The objective is to convey the complexity of implementing this system as well as reviewing the lessons learned from this experience.

This paper examines the capability of the Reynolds-averaged thin-layer Navier-Stokes codes to simulate the results from a two-dimensional aileron effectiveness test. This unique test was carried out in the IAR high Reynolds number wind tunnel and addressed the effects of Reynolds number, Mach number and angle-of-attack on aileron effectiveness. The test results showed a highly nonlinear variation of lift for downward trailing edge deflections. It provides a valuable database for using CFD to determine the adequacy of the corrections applied to the experimental data due to the presence of the wind tunnel walls, and for assessing the current CFD capability to model the flowfield with separation. CFD predictions are obtained by using CFL3D with the Spalart-Allmaras turbulence model and TLNS2D with the modified Johnson-King turbulence model.

Burr research is undeniably highly complex. In order to advance understanding of the process involved several techniques are being implemented. First a detailed and thorough examination of the burr forming process is undertaken. The technique is difficult, intricate and time consuming, but delivers a large amount of vital physical data. This information is then used in the construction of empirical models and, in some case lead to development of FEM models. Finally using the model as a template, related burr formation problems that have not been physically examined can be simulated and the results used to control process planning resulting in the reduction of burr formation. We highlight this process by discussing current areas of research being followed at the University of California in collaboration with Boeing and the Consortium on Deburring and Edge Finishing (CODEF).

The IATCS coolant has experienced a number of anomalies in the time since the US Lab was first activated on Flight 5A in February 2001. These have included: 1) a decrease in coolant pH, 2) increases in inorganic carbon, 3) a reduction in phosphate concentration, 4) an increase in dissolved nickel and precipitation of nickel salts, and 5) increases in microbial concentration. These anomalies represent some risk to the system, have been implicated in some hardware failures and are suspect in others. The ISS program has conducted extensive investigations of the causes and effects of these anomalies and has developed a comprehensive program to remediate the coolant chemistry of the on-orbit system as well as provide a robust and compatible coolant solution for the hardware yet to be delivered.

For new aircraft production, initial production typically reveals difficulty in achieving some assembly level tolerances which in turn lead to non-conformances at integration. With initial design, tooling, build plans, automation, and contracts with suppliers and partners being complete, the need arises to resolve these integration issues quickly and with minimum impact to production and cost targets. While root cause corrective action (RCCA) is a very well know process, this paper will examine some of the unique requirements and innovative solutions when addressing variation on large assemblies manufactured at various suppliers. Specifically, this paper will first review a completed airplane project (Project A) to improve fuselage circumferential and seat track joins and continue to the discussion on another application (Project B) on another aircraft type but having similar challenges.