Breakout Session

This presentation focuses on the simulation of Electromagnetic Environmental Effects (E3) and in particular direct lightning strike on an aircraft. The coupling on cables inside the aircraft is simulated with a 3D-2D EM/circuital EM approach so that the currents induced on inner conductors connected to attached loads are predicted. Modern aircraft often use advanced composite materials due to their superior mechanical properties. However, they are significantly less electrically conductive than traditionally used aluminum. Therefore layer of conductive fibers or screens designed to carry lightning currents are embedded in the composite stack up. In this talk the effects of the high current flowing on the fuselage onto the Lightning Struck Panel Breakage Under Compressive Load is shown. Then a video is commented where the Simulation task is defined by the Project Manager in a Collaborative space where stakeholders are identified and project duration is fixed. The analyst is then alerted to make the analysis starting from a CAD file he can easily located using a 6WTags approach. The Electromagnetic model is then prepared including the sources, boundary conditions, scenario and saved for future usage. After visualization of the results a what-if analysis is done moving the end point of the cable. The Harness designer makes the change and automatically the Electromagnetic model gets updated, saving lots of time. At the end results for the 2 cable configurations are presented in smart way using a Viewer usable on a Tablet the Project Manager can bring in a meeting to finally decide on the best action to take.

The present work aims to describe a novel numerical tool developed for the structural optimization of metallic lattice structure. The implemented structures consisting in an outer skin, an internal lattice structure, and a potential inner skin useful to model structure with internal cavities. The optimization procedure involves two commercial software: ANSYS and ModeFrontier. The first one is dedicated to pre and post-process activities, while the second one is dedicated to the optimization flow management. In order to reduce the computational cost, the tool models the structure by means of simplified element: shells and beams. Nevertheless, at the end of the optimization process, the tool generate automatically a full 3D model, that can be exported in a CAD format and just ready for the manufacturing process. The tool was used to design several axial-symmetric lattice structures under compressive static loading conditions. A specific test case was manufactured (using the EBM technology) and validated experimentally. The presented test case aims to underline the advantage in using such kind of structures to improve the performance of slender structures.

CAE models generated from 3D image data enable analysis of complex artificial and natural structures. These models also provide a valuable resource for non-destructive inspection, for example of defects and microstructural details. In this presentation, we will discuss some of the current techniques in image-based modelling and simulation, and how they are being applied by innovative success stories.
Bird nests offer one excellent example of using image-based simulation to approach engineering challenges. A workflow using Synopsys Simpleware software generated models of edible-swiftlet nests from micro-CT and involved segmentation and export of Finite Element (FE) models for simulation in Abaqus. This work looked at how the production of nests has similarities to Additive Manufacturing through mechanical overdesign of an optimized structure for handling stress, as well as showing how complex structures can be built using local or self-produced materials.

This paper is to expound the practical experience fueled and market tendencies driven innovation at eCon Engineering Ltd. These activities mostly connected to mechanical finite element method-based calculations of fiber reinforced polymer composites. These solutions have large spectrum but this article focuses on the characterization of ply-level properties and failure criteria from simple material tests and layer build-up optimization of composite structures. Using these methods more efficient composite structures can be designed and produced via better cost-performance trade-offs. The newly developed methods lead us to the better understanding of design principles and possibilities of these materials and allow us to expand the spectra of our engineering services as well.

Over the years Computational Fluid Dynamics has gradually increased its importance within the Air Vehicle Technology department of Leonardo Aircraft Division. Thanks to the enhanced computational capabilities and modern software reliability, the use of CFD nowadays is not only limited to comparative studies, but it is becoming a reliable alternative to wind tunnel tests for aerodynamic datasets generation. Modern high-performance military aircrafts are very complex machines where many systems are integrated and mutually influenced, therefore in a preliminary design phase, it is crucial to assess the performance of the aircraft and all its sub-systems, as well as its capabilities. To this end, a fully comprehensive aerodynamic dataset is of paramount importance since it is the first input for most of all the other physical models. Due to major changes on the M346 aircraft, introduced to extend its operational capabilities, the need to update the aerodynamic dataset has arisen. Time and cost constraints have precluded a wind tunnel test campaign, therefore it has been opted to proceed with computational methods. Within this process, the complete CFD methodology has been revised and partially automated to minimize the man hours and ensure the consistency of the results.

Guided waves are considered as one of the most encouraging tools for quantitative and qualitative identification of defect/damage in metallic and composite structures. Among these, Lamb waves can be excited in plate-like thin plate with parallel free boundaries, they can travel over a long distance even un materials with high attenuation ratio and have a high sensitivity to interference on a propagation path. For these reasons, Lamb waves can be exploited to quickly inspect a broad area so allowing for a structural monitoring. In this work, the propagation properties of Lamb waves were analytically calculated solving the transcendental Rayleigh-Lamb equation in Matlab. The propagation of Lamb waves in a isotropic plate was studied by Finite Element Method in Ansys. Coupled field transient analyses were carried out in order to simulate the action of PZT disks bonded onto the structure and to understand the mechanism of different mode excitation. The FE models were validated and calibrated by experimental campaigns.

Designing airframe structures has traditionally been a challenging task. The structures must guarantee absolute safety and integrity under a high number of loading conditions while fulfilling several functional requirements. Also minimizing weight represents a major goal to achieve target performances and flight envelope. Typical challenges in terms of development time and costs for commercial engineering groups does not make it easier. In the last decade, aeronautic companies have been increasingly exploiting a simulation design approach to tackle these challenges. In particular, structural optimization has become a mainstream technology and has been increasingly integrated into design processes. This presentation will overview industrial adoption showing real-world examples from Airbus, Boeing, Rolls-Royce and others, discussing than more in detail two very recent applications: Leonardo’s Next Generation Tiltrotor and AW189. Challenges and opportunities in terms of methods and tools as well as process integration will be discussed.