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Purpose The purpose of this study is to report results of the qualitative assessment of AZ31 aircraft brackets with a triangular rib produced by a new forging method with respect to their structure and mechanical properties.Design/methodology/approach The paper reports the results of qualitative tests for AZ31 magnesium alloy aircraft brackets with a triangular rib produced by a new forging method. These ribbed parts were formed on a forging press equipped with three moving tools. The produced aircraft brackets were subjected to qualitative tests. Their cross-sectional microstructure was examined using the light-field technique. The mechanical properties of ribbed parts were determined in a static tensile test and by hardness measurements on the surface of the part. The following variables were determined: tensile strength Rm, yield strength R0.2, elongation A5 and hardness.Findings The results of qualitative tests provide significant information about produced aircraft brackets with a triangular rib, i.e. microstructure in three key regions of brackets and their mechanical properties.Practical implications The method will enable producing magnesium alloy aircraft brackets with a triangular rib. The application of the method for aircraft brackets developed by the authors of this paper will result in higher product quality and reduced production costs. The paper demonstrates the practical application of this technique by presenting a finished aircraft bracket and the results of complete qualitative tests.Originality/value The originality of this paper lies in the presentation of a new, innovative method for manufacturing aircraft brackets with a triangular rib. This method is unique on a global scale, and its assumptions have been granted patent protection. [ABSTRACT FROM AUTHOR]

Abstract Due to manufacturing variations of composite parts, assembly gap and consequent shimming widely occur in the airframe skin-structure. To guarantee the safety and reliability, the aircraft manufacturers expect to fully understand the effect of assembly gap and shimming on the loading behavior of composite skin joints. One of the main concerns is the effect of interface gap and shimming on the elastic stress state at the hole due to skin joints involve significant stress concentration and composite parts present brittleness and limited stress relief ability. But this topic has not yet been reported so far. In this paper, the effect of joining interface condition (including both shimming and interface gap) on three-dimensional layer-by-layer stress field at the countersunk hole of single-lap countersunk composite joints was fully and systematically investigated by employing a three-dimensional FE model. Shimming conditions include material type and shim thickness, and interface gap conditions include gap span and gap thickness. Some previously unrevealed conclusions were concluded. This study could contribute to improving the reliability of composite airframe, and benefit both design and manufacture in aircraft industry. [ABSTRACT FROM AUTHOR]

Purpose – This paper aims to describe a new methodology for controlling highly flexible automated manufacturing cells for use in aerospace manufacturing and repair. Design/methodology/approach – The design methodology and rational of the FLEXA control architecture are described along with it implementation and testing. Findings – The trials completed so far show that the level of flexibility required can be achieved both at factory, or enterprise level, and at shop floor level. Practical implications – This work has significant practical implications through its direct applicability for aerospace and other automated manufacturing processes. Originality/value – The originality of the paper lies in the truly flexible nature of the control system described and its ability to mimic traditional cell control architectures but be expanded through the use of virtual Programmable Logic Controller to control any number of cells without the need for significant extra hardware. [ABSTRACT FROM AUTHOR]

In order to improve the accuracy of productivity calculation and prediction, this paper aims to establish a mathematical model, which takes multi-factor revision into account, to evaluate the personnel operational capacity (POC) of aircraft assembly lines. Firstly, the assembly operation is divided into assembly operating elements (AOEs), which is based on the features of aircraft assembling and is for the provision of statistical units. Secondly, effective man-hour (EMH) is adopted as a yardstick to measure the POC. Then, considering the technical characteristics and environmental constraints of the real assembly line, detailed quantitative descriptions about the chosen key factors, namely assembling accuracy, learning effect, and assembling intensity, are provided, and these quantitative descriptions are used for the revision of the EMH in order to guarantee a higher precision. After that, several critical parameters such as the cycle time, tact time, and output of an assembly line can be solved out, from which the POC can be analyzed and reflected. Finally, this method has been successfully applied to a practical case, and the result justifies its advantage as well as feasibility. [ABSTRACT FROM AUTHOR]