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Metal matrix composites (MMCs) exhibit superior characteristics such as low weight, high stiffness, and high mechanical and physical properties. Inheriting such an outstanding combination of specifications, they are nowadays considered as the promising materials in the aerospace and biomedical industries. However, the presence of high abrasive reinforcing particles in MMCs leads to severe manufacturing issues. Due to the tool-particle interactions which occur during the machining of MMCs, high tool wear and poor surface finish are induced and those elements are considered as the main drawbacks of cutting MMCs. In this study, dry turning experiments were conducted for two different inserts and coated carbide on a bar of titanium metal matrix composite (Ti-MMC). Semi-finishing machining is operated with cutting parameters based on the tool supplier's recommendations which were not fully optimized. The maximum flank wear length (VBBmax) was selected as the tool wear criteria.

The need for efficient manufacturing approaches has emerged with the increasing usage of composites for structural components in commercial aviation. Resin Transfer Molding (RTM), a process where a fiber preform is injected with resin into a closed tool, can achieve high fiber content required for structural components as well as improved dimensional accuracy since all surfaces are controlled by a tool surface. Moreover, RTM is well suited for parts that can be standardized throughout the aircraft, such as a fuselage frames and stringers. The objective of this investigation is to develop a preforming approach for a C-Shaped Fuselage frame. Two approaches are proposed: tri-axial braiding and hand lay-up of Non-Crimp Fabrics. The fiber architecture of the basic materials as well as the complete preforms is explained. The necessary preforming operations are detailed. The quality control measurement of fiber orientation and thickness are presented.

Implementing Design for Environment (DfE) into the design process requires a strategic integration. Furthermore, as DfE is continuously evolving, flexible processes need to be implemented. This article focuses on the integration of DfE into an optimization framework with the objective of influencing next-generation aircraft. For this purpose, DfE and Structures groups are developing together a set of new environmental indicators covering all life cycle stages of the product by coupling a list of yes/no questions with an environmental matrix. The following indicators are calculated: Regulation risk, Impact of manufacturing the part, CO2 emissions and Recyclability potential. These indicators will be used as constraints in the multi-disciplinary design optimization (MDO) framework, meaning that the structure will be designed while complying with environmental targets and anticipating future regulation changes.

The objective of this document is to present the methodology used to verify the structural integrity of a redesigned composite part. While shifting the manufacturing process of a composite part from pre-impregnated to a liquid resin injection process, the Composites Development team at Bombardier Aerospace had to redesign the component to a new set of design allowables. The Integrated Product Development Team (IPDT) was able to quickly provide a turnkey solution that assessed three aspects of airframe engineering: Design, Materials & Processes (M&P) and Stress. The focus of this paper will be the stress substantiation process led by the Stress Engineers. It will also bring up the synergies with M&P that are unique to the IPDT approach. The stress substantiation process required three distinct checks be confirmed.

During the course of an aircraft program, cost and weight savings are two major areas demanding constant improvements. An Integrated Product Development Team (IPDT) was set to the task of proposing potential improvements to an aircraft under development. From a list of potential parts, the IPDT selected one which was considered as the most suitable to leverage a co-curing process. In the aircraft manufacturing industry, any major modification to a part design should follow the program's means of compliance to certification. Furthermore, to demonstrate the new design's safety, sizing methodology and all supplementary testing must fit in the certification strategy. The IPDT approach was used to ensure the maturity of both process and part. Indeed, a mature turnkey solution can be implemented quickly on the shop floor. This IPDT approach is detailed in another SAE 2013 technical paper entitled: “A Novel Approach for Technology Development: A Success Story” [3].

Manufacturing operations introduce unreliability into hardware that is not ordinarily accounted for by reliability design engineering efforts. Inspections and test procedures normally interwoven into fabrication processes are imperfect, and allow defects to escape which later result in field failures. Therefore, if the reliability that is designed and developed into an equipment/system is to be achieved, efforts must be applied during production to insure that reliability is built into the hardware. There are various ways to improve the reliability of a product. These include: Simplification Stress reduction/strength enhancement Design Improvement Using higher quality components Environmental Stress Screening before shipment Process Improvements, etc. This paper concentrates on ‘Manufacturing Process Improvement’ effort through the use of design of experiments, (DOE). Hence, improved levels of reliability can be achieved.

Bombardier faced new manufacturing process challenges drilling and fastening CSeries* aircraft panels with multi-material stacks of composite (CFRP), titanium and aluminum in which Gemcor responded with a unique, flexible CNC Drivmatic® automatic fastening system, now in production at Bombardier. This joint technical paper is presented by Bombardier, expounding on manufacturing process challenges with the C Series aircraft design requirements and Gemcor presenting a unique solution to automatically fasten CFRP aft fuselage panels and aluminum lithium (Al Li) cockpit panels with the same CNC Drivmatic® system. After installation and preliminary acceptance at Bombardier, the CNC system was further enhanced to automatically fasten the carbon fiber pressure bulkhead dome assembly.

This paper presents work on the development of a low cost fuselage C-frame for aircraft primary structure using a Light Resin Transfer Molding (RTM) process. Compared to labor intensive hand layup prepreg technologies, Light RTM offers some substantial advantages by reducing infrastructure requirements such as hydraulic presses or autoclaves. Compared to Prepreg, Light RTM tooling creates two finished surfaces, which is an advantage during installation due to improved dimensional accuracy. The focus of this work was to develop means of achieving high fiber volume fraction structural frames using low cost tooling and a low volume manufacturing strategy. In this case a three piece Light RTM mold was developed using an internal mandrel. To achieve the strength requirements, a combination of crimped and non-crimped fabrics were selected for the reinforcing preform.

Nowadays, optimization of manufacturing and assembly operations requires taking into account the inherent processes variations. Geometric and dimensional metrology of mechanical parts is very crucial for the aerospace industry and contributes greatly to its. In a free-state condition, non-rigid parts (or compliant parts) may have a significant different shape than their nominal geometry (CAD model) due to gravity loads and residual stress. Typically, the quality control of such parts requires a special approach where expensive and specialized fixtures are needed to constrain dedicated and follow the component during the inspection. Inspecting these parts without jig will have significant economic impacts for aerospace industries, reducing delays and the cost of product quality inspection. The Iterative Displacement Inspection (IDI) algorithm has been developed to deal with this problem.