Marcus Sandberg

Functional Product Life-cycle Simulation Model for Cost Estimation in Conceptual Design of Jet Engine Components

As functional (total care) products emerge in the jet engine industry, the need for product life-cycle models capable of definition and evaluation of life cycle properties increases, since functional products (FP) includes both hardware and service. Recent life-cycle models are intended for hardware products and mostly handle design and manufacturing knowledge. The aim of this article is to present a design approach that extends the evaluation capabilities beyond classical hardware design and manufacturing evaluation. The focus has been to introduce evaluation of manufacturing and post-manufacturing activities in evaluation of conceptual designs. For this purpose, a model has been proposed to handle the information flow between teams when developing structural jet engine components. A case study, in which the proposed model was used in cooperation with a jet engine component manufacturer, is presented. Aspects concerning design, manufacturing, performance, and maintenance of jet engine flanges were included in the example by means of a knowledge based engineering (KBE)-system coupled to databases and spreadsheets. The model is more suitable than recent work for the development of hardware parts of functional products (HFP), since knowledge from more product development disciplines is included. As the engineer changes the design and directly assesses the life-cycle cost (LCC) and how the changes impact the interface to other jet engine components, more knowledge on the impact of design decisions is available at hand for the engineering designer than without the model.

A study of a plan-do-check-act method used in less industrialized activities : two cases from industrialized housebuilding

In construction projects, a large number of deviations are usually found during inspections and adjusted in a reactive manner. For projects to become proactive, root causes need to be identified and eliminated as a part of a process of continuous improvement (CI). Plan-do-check-act (PDCA) methods are part of CI and have been used with success within the manufacturing industry for decades. Research studies of PDCA in construction are less common, which could be explained by the past dominance of the project-based nature of construction compared to the process-based nature of manufacture. Industrialized construction, however, has changed this picture somewhat, and it is of interest to find out how well it works for less industrialized activities in construction. A PDCA method was tested in two cases selected from one medium-sized Swedish industrialized housebuilder, which uses a building system based on offsite manufactured modules. Empirical results are based on systematic data gathered through interviews and participant observations. Results from the two cases show that the PDCA method worked even when processes were divided into industrialized parts within a factory and non-industrial parts at the construction site although this might lead to temporary corrective actions rather than permanent process actions.

A Knowledge-based Master-model Approach with Application to Rotating Machinery Design

Novel rotating machinery design concepts and architectures are being explored to reduce mass, energy consumption, manufacturing costs, and environmental impact while increasing performance. As component manufacturers supply parts to original equipment manufacturers, it is desirable to design the components using a systems approach so that they are optimized for system-level performance. To accomplish that, suppliers must be able to model and predict the behavior of the whole machinery. Traditional computer-aided design/computer-aided engineering master-modeling approaches enable manual changes to be propagated to linked models. Novel knowledge-based master-modeling approaches enable automated coordination of multidisciplinary analyses. In this article, we present a specific implementation of such a knowledge-based master-modeling approach that facilitates multidisciplinary design optimization of rotating machinery. The master-model (MM) approach promotes the existence of a single governing version of the product definition as well as operating scenarios. Rules, scripts, and macros link the MM to domain-specific models. A simple yet illustrative industry application is presented, where rotor-dynamics and displacement analyses are performed to evaluate relocation alternatives for the rear bearing position of a rotating machinery under a ‘fan-blade-off’ load case.

A knowledge-based master model approach exemplified with jet engine structural design

Successful product development requires the consideration of multiple engineering disciplines and the quantification of tradeoffs among conflicting objectives from the very early design phases. The single-largest challenge to do so is the lack of detailed design information. A possible remedy of this issue is knowledge-based engineering. This paper presents a knowledge-based master model approach that enables the management of concurrent design and analysis models within different engineering disciplines in relation to the same governing product definition. The approach is exemplified on an early phase structural design of a turbo-fan jet engine. The model allows geometric-, structural mechanics- and rotor-dynamic- models to be concurrently integrated into a multi-disciplinary design and optimization loop.

AUTOMATING REDESIGN OF SHEET-METAL PARTS IN AUTOMOTIVE INDUSTRY USING KBE AND CBR

Automating redesign is an approach for engineering designers to prevent design related manufacturability problems in early product development and thus reduce costly design iterations. A vast amount of work exists, with most research findings seemingly staying within the research community rather than finding its way into use in industrial settings where research issues have often evolved from the concerned applied research. The aim of this paper is to present an approach with industrial implementation potential regarding automating redesign of sheet-metal components in early product development to avoid manufacturing problems due to design flaws and non-optimal designs. Geometry, generated by a knowledge-based engineering (KBE) system, gives input to the case-based reasoning (CBR) governed manufacturing planning. If geometry is found non-manufacturable or enhancement of already manufacturable geometry is possible, the CBR system will suggest redesign actions to resolve the problem. CBR extends the capabilities of the rule-based KBEsystem by enabling plan-based evaluation. The approach has the potential for industrial implementation, since KBE is often closely coupled to an industrial CAD-system, hence enabling technology is at the industry. Also, combining KBE and CBR reduces the coding effort compared to coding the whole design support with CBR, as feature recognition is simplified by means of KBE. A case study of development of sheet-metal manufactured parts at a Swedish automotive industry partner presents the method in use. As it is shown that redesign can be automated for sheet-metal parts there is a potential for reducing costly design and manufacturing iterations.

Jet Engine Design Optimization Using a Knowledge-Based Master Model

This paper presents a preliminary design optimization study of a jet engine structure using a knowledge-based master modeling approach. The objective function is derived based on input-output relationships of a cost-performance model, where specific fuel consumption, pressure loss and direct cost are considered. The advantage of this problem formulation is that it entails a single composite objective function that takes into account mass, structural characteristics, dynamic response and translates them to a direct operational cost function to be minimized. A fan-blade-off scenario is considered as the loading case in this paper. The loss of one fan blade during nominal operation causes a rotor imbalance and structural deformation.Copyright

Modularization based on commonalities in house-building requirements

Some of the requirements governing the design of houses are common between projects. This opens up for using modularization based on product commonalities. Though modularization is well known in th ...

A proactive plan-do-check-act approach to defect management based on a Swedish construction project

In order to continuously improve quality and avoid reoccurrence of defects, defect management (DM) in construction needs to take a more proactive approach. The classification of construction information is important for the efficient exchange and integration of data between the many roles and phases of construction and facility management, but it also provides a framework for standardization, which in turn is paramount for improvement. In order to better understand how defects can be managed proactively we conducted a case study on inspection practices at a large construction project in Sweden, using observation and analysis of inspection reports. We identified opportunities and obstacles in the classification of defect data. The project’s defect descriptions were often ambiguous and the records lacked important contextual information. We believe that this was because current practice is not designed with proactivity in mind, and there are only regulatory requirements on the data, making classification difficult. In addition, by viewing the project’s practices through the lenses of continuous improvement and plan-do-check-act theory to identify missing or inadequate steps, we propose a framework for a proactive version of the current defect management process that could potentially help to prioritize improvement work and reduce the incidence of defects.

Towards a knowledge-based engineering methodology for construction

The increasing industrialization and standardization of construction opens up for the field of design automation, and possibilities to work with several what-if-conditions and several product candi ...