Published Article / At Helsinki University of Technology rapid prototyping, rapid tooling and rapid manufacturing technologies and applications have been researched since late 1980s. The Integrated Design and Manufacturing research group has concentrated on new industrial Rapid Prototyping and Manufacturing (RP&M) applications within product development and manufacturing. This paper is based on research projects realized in 2001 - 2004 in cooperation with several industrial companies. New developments within industrial product development paradigms and processes will be discussed. The paper attempts to link current industrial management sciences research with latest developments within rapid manufacturing technologies. Product platforms, product customization and networked manufacturing have become common product development management paradigms in many industrial sectors. These paradigms have lead to an increasing number of product configurations and variations. Traditionally cost comparisons between RP&M processes and conventional manufacturing processes have been based on break even point calculations. The latest product development and manufacturing paradigms places agility in production and efficient prototyping technologies among others in an important role. Conventional cost per part comparison methods to value rapid manufacturing need to be re-engineered. In those comparisons the first break even point does not describe the overall rapid manufacturing economy. For example, effects of neccesity for product change, tool wear or tool defect have to be taken into consideration. In this paper the new cost modeling technology and some industrial case studies will be described.

Published Article / Rapid tooling (RT) in the context of this research presents the possibility of improving the traditional investment casting process by shortening lead times while still maintaining affordable costs and required quality. Various rapid prototyping processes are available that can be used to create direct metal, polymer or wooden dies for this casting technology. This paper presents results gained in an AMTS project, focusing on RT development for investment casting of light metals. One of the most widely used layer manufacturing processes available in South Africa is selective laser sintering. A machine produced by the German manufacturer EOS (process known as laser sintering) utilising this technology was selected for the study. Two of the materials that are suitable for rapid die making are used, which in tum reflects different mechanical properties and process economics. A standard benchmark part was used as a study base. Two dies were built, one in alumide and one in polyamide. A comprehensive measurement programme was conducted, followed by an appropriate statistical analysis and evaluation regarding accuracy and surface finish. A number of wax patterns were produced. The best wax patterns from each die were selected and evaluated. The subsequently produced castings in AI, Mg and TI were further examined and evaluated. Various issues concerning the reinforcement, wax injection, pattern removal, accuracy and surface finish of the dies are discussed in the paper. The research concludes that rapid tooling techniques can be successfully used for creating accurate dies in order to shorten lead times in the investment casting process chain.

Additive manufacturing processes, which utilize selective deposition of material rather than traditional subtractive methods, are very promising due to their ability to build complex, highly specific geometries in short periods of time. Three-dimensional direct inkjet printing is a relatively new additive process that promises to be more efficient, scalable, and financially feasible than others. Due to its novelty, however, numerous technical challenges remain to be overcome before it can attain widespread use. This thesis identifies those challenges and finds that material limitations are the most critical at this point. In the case of deposition of high viscosity polymers, for example, it is found that droplet formation is a limiting factor. Acoustic resonance jetting, a technology recently developed at Georgia Institute of Technology, may have the potential to address this limitation because it generates droplets using a physical mechanism different from those currently in use. This process focuses ultrasonic waves using cavity resonances to form a standing wave with high pressure gradients near the orifice of the nozzle, thereby ejecting droplets periodically. This thesis reports initial exploratory testing of this technologys performance with various material and process parameters. In addition, analytical and numerical analyses of the physical phenomena are presented. Results show that, while the pressures generated by the system are significant, energy losses due to viscous friction within the nozzle may prove to be prohibitive. This thesis identifies and begins evaluation of many of the process variables, providing a strong basis for continued investigation of this technology.

The Capital Metropolitan Transportation Authority is currently in the stages of implementing Austin’s first bus rapid transit line along one of the city’s principal urban corridors. The line will run approximately 20 miles, along North Lamar, Guadalupe and South Congress Avenue. Considering the key role that land use patterns play in determining ridership for mass transit systems, transit agencies are increasingly pursuing strategies to encourage transit-oriented development as a means of securing the success of their transit investments. Considering the relatively intense uses already existing along this corridor, the location of some of the city’s primary institutions along it, and its general importance in defining the “image” of the city, this corridor seems ideally situated to absorb significant density increases. The focus of this study, therefore, is to evaluate the general need for increased densities and transit-supportive development along Austin’s BRT starter route, to examine the overall ability of bus-based transit to generate development pressures, to outline some of the land use policies necessary for encouraging TOD, and finally, to suggest an ideal planning approach for encouraging transit-supportive development along Austin’s BRT corridor. / text

Stuttgart, Univ., Diss., 2006.

This research identifies large-scale synoptic controls that are relevant for rapid intensification (RI) in the Atlantic basin. Spatial statistical analysis techniques were performed on NASA MERRA data from 1979–2009. Rotated principal component analysis (RPCA) was performed, looking for common patterns in the datasets. The RPC’s were grouped using hierarchical clustering techniques, allowing for finding events similar in synoptic structure. The clustered events, representing the total RI and non-RI composites, were averaged yielding composite maps for different scenarios. To verify the results, a permutation test was done to show which variables are good distinguishers of RI and non-RI cases. These variables were used as input in two prediction schemes: logistic regression and support vector machine classification. The prediction scheme was a slight improvement in forecasting RI when using the synoptic variables mid-level vorticity, vertical velocity, low-level potential temperature and specific humidity, as the most significant in predicting RI.

The U.S. military must have the ability to rapidly deploy troops and equipment anywhere in the world as part of a contingency operation. Recent military operations have highlighted the critical need for rapid repair procedures and materials for military use on sub-standard, in-theater airfields. The U.S. Army Corps of Engineers, Engineer Research and Development Center is currently addressing these problems through a program titled ?Joint Rapid Airfield Construction?. This study involves the development of a method using rapid setting grouts and recycled concrete pavement (RCP) to repair portland cement concrete (PCC) pavements. A laboratory study was conducted to evaluate material properties in order to gain an understanding of expected field performance. Eight full scale repairs were constructed using two rapid setting grouts, two types of equipment, and two concrete slabs. The repairs were successfully trafficked with simulated C-17 aircraft wheel loads to verify the structural capacity, and ultimately the procedures.

This thesis explores the Rapid Recommendations process, a new responsive way of creating clinical practice guidelines. / Healthcare workers rely on clinical practice guidelines to inform their practice. However, most guidelines are not trustworthy when judged by accepted standards and they typically take several years to produce. Guideline trustworthiness is undermined by panel members who often have conflicts of interest, by including representation from only a subset of stakeholders, by failing to examine the entirety of the evidence systematically, and by rapid obsolescence. Further, they are often difficult for users to understand in limited time. Rather than updating guidance on a fixed schedule, the Rapid Recommendations approach involves continuous monitoring of the literature and produces guidelines in response to new potentially practice-changing evidence. A collaborative network of clinicians, methodologists, and patients respond by rapidly producing trustworthy evidence syntheses and guidance. We have identified efficiencies at every step of the guideline development process. The guideline panel does not include anyone with a financial conflict of interest and there are strict limits professional and intellectual conflicts. Systematic reviews are produced on the relative effects of each option, on prognosis, and on patient values and preferences with the explicit intent to inform the question at hand. The panel also considers practical issues. Rapid Recommendations are published in a concise multilayered user-friendly format headed by an interactive infographic that contains all of the necessary information for users need to make informed decisions at the point of care. The guideline is published simultaneously in print and electronically, including decision aids that can be used at the point of care and integrated into electronic medical records. In this thesis, you will find a selection of exemplary publications relevant to the Rapid Recommendations process. We show that a responsive approach to rapid and trustworthy guideline creation is possible. It represents a way forward from the current limitations that plague most current clinical practice guidelines. / Thesis / Candidate in Philosophy / Healthcare workers often decide what to do in practice based on the advice of experts through clinical practice guidelines. However, most clinical practice guidelines are not completely trustworthy. Guideline authors often have conflicts of interest, do not include patients or patient views, and are created so slowly that they rapidly fall into obsolescence. This thesis explores a new way of developing clinical practice guidelines that we call Rapid Recommendations. Instead of creating them on a fixed schedule (i.e., every few years), they are created in response to new studies that might change practice. The scope is limited, and timelines are shorter, meaning that the guidelines are published sooner. The guideline authors include all stakeholders, including patients. None of the authors have any financial interests in the topic, and other conflicts are minimized. The guidelines are published on an expedited basis and in an accessible online multilayered format with infographics. This thesis includes a selection of exemplary publications relevant to the Rapid Recommendations process.

The trends of rapid manufacturing (RM) have influenced numerous developments of technologies mainly in additive processes. However, the material compatibility and accuracy problems of additive techniques have limited the ability to manufacture end-user products. More established manufacturing methods such as Computer Numerical Controlled (CNC) machining can be adapted for RM under some circumstances. The use of a 3-axis CNC milling machine with an indexing device increases tool accessibility and overcomes most of the process constraints. However, more work is required to enhance the application of CNC for RM, and this thesis focuses on the improvement of roughing and finishing operations and the integration of cutting tools in CNC machining to make it viable for RM applications. The purpose of this research is to further adapt CNC machining to rapid manufacturing, and it is believed that implementing the suggested approaches will speed up production, enhance part quality and make the process more suitable for RM. A feasible approach to improving roughing operations is investigated through the adoption of different cutting orientations. Simulation analyses are performed to manipulate the values of the orientations and to generate estimated cutting times. An orientations set with minimum machining time is selected to execute roughing processes. Further development is carried out to integrate different tool geometries; flat and ball nose end mill in the finishing processes. A surface classification method is formulated to assist the integration and to define the cutting regions. To realise a rapid machining system, the advancement of Computer Aided Manufacturing (CAM) is exploited. This allows CNC process planning to be handled through customised programming codes. The findings from simulation studies are supported by the machining experiment results. First, roughing through four independent orientations minimized the cutting time and prevents any susceptibility to tool failure. Secondly, the integration of end mill tools improves surface quality of the machined parts. Lastly, the process planning programs manage to control the simulation analyses and construct machining operations effectively.

published_or_final_version / abstract / Mechanical Engineering / Master / Master of Philosophy