CAE tools Using suitable CAE tools for the development of complex FRP parts RUAG has a long tradition in the design and manufacturing of structural aircraft components using carbon-fibre-reinforced plastics. Over the last few years, the capabilities of computer-aided engineering tools allowing integrated development based on a digital mock-up have been developed. The company has applied these tools within several industrial projects. The complete process – from specification to the cured composite part – is described in this paper that gives an insight into the process steps, the benefits but also the challenges that were encountered. By Holger Könen, Manager Structural Design Stefan Von Bergen, Department Manager Structural Engineering RUAG Aviation reduce this drawback is the use of efficient computer-aided engineering (CAE) and computer-aided manufacturing (CAM) tools. Ideally, integrated tools are used to assist design and manufacturing based on a common digital mockup (DMU). Fig. 1 gives an overview of the different design activities associated with the DMU. The interactions between the different departments such as design, production engineering, workshop and quality are normally more intense and the feedback from production has typically more of an impact on the design solution compared to that of metallic structures. The development process involves the following steps: - Determination of material properties based on sample probes (including non-standard environmental conditions) - Integration of the material properties into the computeraided design (CAD) tool - Development of the part: -Initial lay-up concept - Initial static stress loop - Producibility assessment - Design optimizations (iterations) - Generation of production data - Export of numerically-controlled (NC) cutter data - Export of laser projection data - Tool manufacturing - Prototype/part manufacturing - Design improvements T his paper describes the procedure for developing an aircraft structural part made of fibre-reinforced plastics (FRP) by using modern CAE tools. The goal is to illustrate how the departments involved can take advantage of the use of these tools. In addition to the almost unlimited possibilities with regard to the shape of a part and the opportunity of integrating details, tailoring strength and stiffness properties at low weight is the most important advantage of FRP structures compared to metallic structures. The price for these benefits is a heavier design and manufacturing effort compared to metallic structures. A way to 52 jec composites magazine / No80 April 2013 Fig. 1: Common DMU for the complete development process