Marcus Sandberg

... defended in public at Luleå University of Technology in room E246, December 19, 2007 at 9.00 am Opponent at public defence: Professor Johan Malmqvist, Chalmers, Gothenburg ... Henrik Nergård, for being such a nice guy and for a good time in E210b–don't get me wrong man. ...

abstract: The jet engine industry relies on product models for early design predictions of attributes such as structural behavior, mass and cost. When the required analysis models are not linked to the governing product model, effective coordination of design changes is ...

ABSTRACT 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.

ABSTRACT 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.

ABSTRACT 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.

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