G. La Rocca

Enabling distributed multi-disciplinary design of complex products: a knowledge based engineering approach

In this paper, it is discussed how knowledge based engineering has been exploited to develop a flexible design system, able to integrate a heterogeneous set of distributed discipline-specific design and analysis tools into a modular design framework. This system, called Design and Engineering Engine (DEE), demonstrated its capability to support designers in performing what-if studies and accelerate Multi-disciplinary Design and Optimisation (MDO), through the automation of those lengthy and repetitive activities typically hampering the design process. Design quality and innovation are also supported by enabling the use of high fidelity analysis tools in the early design phase.

Knowledge-based engineering to support aircraft multidisciplinary design and optimization

Abstract This paper discusses structure and functionalities of a knowledge-based engineering (KBE) application, called multimodel generator (MMG), developed to support aircraft multidisciplinary design, analysis, and optimization. Designers can use the MMG as an advanced modelling tool to swiftly generate geometrical models of many and diverse aircraft configurations and variants, by combining and adjusting a limited number of parametric objects, called high-level primitives. Besides capturing the geometric aspects of the design, the MMG also has the capabilities to automate a large part of the lengthy and non-creative pre-processing activities involved in the design verification process. The proposed KBE application has demonstrated to be a valuable solution for some of the critical needs indicated by the multidisciplinary design and optimization community, namely a flexible and robust generative tool to increase the level of automation in aircraft design, including the development of novel configurations; the exploitation of high-fidelity analytical tools already in the early design phase; the management of the design activities across distributed networks of disciplines specialists.AbstractThis paper discusses structure and functionalities of a knowledge-based engineering (KBE) application, called multimodel generator (MMG), developed to support aircraft multidisciplinary design, analysis, and optimization. Designers can use the MMG as an advanced modelling tool to swiftly generate geometrical models of many and diverse aircraft configurations and variants, by combining and adjusting a limited number of parametric objects, called high-level primitives. Besides capturing the geometric aspects of the design, the MMG also has the capabilities to automate a large part of the lengthy and non-creative pre-processing activities involved in the design verification process. The proposed KBE application has demonstrated to be a valuable solution for some of the critical needs indicated by the multidisciplinary design and optimization community, namely a flexible and robust generative tool to increase the level of automation in aircraft design, including the development of novel configurations...

An MDO advisory system supported by knowledge-based technologies

Multidisciplinary Design Optimization (MDO) can aid designers to improve already mature design solutions, as well as to explore innovative, complex engineering products. It is a methodology, complete with mathematical formulations, that assists in the optimization of a complex product, whilst considering and exploiting discipline interactions. Although the first MDO applications have been developed decades ago, this discipline is not yet fully exploited within industry. One of the main reasons is the lack of understanding due to the inherent complexity of the discipline itself and the lack of awareness of existing MDO technologies, software and implementation strategies. This paper introduces a potential measure to lower the accessibility level of MDO: an MDO advisory system supported by knowledge-based technologies. This MDO advisory system will enable the user to first specify an MDO problem and it will return a ranked list of suitable MDO architectures, based on the characteristics of the specified problem, to the user. Additionally, the advisory system will support the user during the implementation of the suggested optimization approach by providing (links to) specific documentation and, most of all, take care of some of the software intensive operations required to integrate the selected architecture in a commercial MDO framework. This paper provides an overall discussion of the envisioned advisory system and focuses on the knowledge-based technologies, and the implications of their implementation. These technologies make up the backbone of the envisioned advisory system, including a domain-specific ontology for MDO and a reasoning engine to provide the required reasoning capabilities for advice. Preliminary results include an ontology to enable the use of monolithic and distributed MDO architectures/problems and an extension of the reasoning functionalities of an open-source reasoner. Finally, a combination of a rule engine and query mechanism is proposed to support the use of rules on top of the ontology.

A KBE-enabled design framework for cost/weight optimization study of aircraft composite structures

Traditionally, minimum weight is the objective when optimizing airframe structures. This optimization, however, does not consider the manufacturing cost which actually determines the profit of the airframe manufacturer. To this purpose, a design framework has been developed able to perform cost/weight multi-objective optimization of an aircraft component, including large topology variations of the structural configuration. The key element of the proposed framework is a dedicated knowledge based engineering (KBE) application, called multi-model generator, which enables modelling very different product configurations and variants and extract all data required to feed the weight and cost estimation modules, in a fully automated fashion. The weight estimation method developed in this research work uses Finite Element Analysis to calculate the internal stresses of the structural elements and an analytical composite plate sizing method to determine their minimum required thicknesses. The manufacturing cost esti...

A KBE Application for Automatic Aircraft Wire Harness Routing

Wire harness design is an increasingly complex task. Knowledge Based Engineering (KBE) and optimization techniques can be used to support designers in handling this complexity. The wire harness design process can be divided in three main parts, namely electrical design, configuration design and geometrical routing. This paper describes the latest progress in the development of a KBE application aiming at the automation of the routing phase. Discrete optimization techniques are used to design shortest path harnesses, while complying with different type of constraints. Some preliminary results have been presented in a previous paper, where only geometrical constraints were addressed. However, wire harness design is affected also by other types of rules and constraints, which need to be accounted to obtain more realistic design results from the optimization process. This paper describes some new developments in the routing application to account for the presence of critical zones inside the aircraft. As study case, the presence of heat sources inside the airframe is considered, which either force the harness to be routed elsewhere, or require the use of wire protections, with obvious consequences on weight and manufacturing. First, some mathematic transformation techniques are used to model the presence of heat sources inside the routing environment. Then the A* algorithm is used for compute the 3D routing, aiming at minimum wire harness weight. The main architecture of the routing application is presented and its functionality is demonstrated with samples of wire harness routing inside a wing. The results show that the proposed KBE application can automate the routing of wire harness while taking into account different rules and constraints. The modeling approach for a heat source can be generalized and extended to address other criticality such as abrasion, electromagnetic interference, corrosion, etc. The achieved level of automation relieves designers from the repetitive work associated with the frequent changes affecting the design environment.