GTTC Future of Ground Testing Meta-Analysis of 20 Documents

National research, development, test, and evaluation ground testing capabilities in the United States are at risk. There is a lack of vision and consensus on what is and will be needed, contributing to a significant threat that ground test capabilities may not be able to meet the national security and industrial needs of the future. To support future decisions, the AIAA Ground Testing Technical Committees (GTTC) Future of Ground Test (FoGT) Working Group selected and reviewed 20 seminal documents related to the application and direction of ground testing. Each document was reviewed, with the content main points collected and organized into sections in the form of a gap analysis current state, future state, major challenges/gaps, and recommendations. This paper includes key findings and selected commentary by an editing team

DESIGN FOR ADDITIVE MANUFACTURING (DfAM) OF LARGE SIZE PRODUCTS USING A PLASTIC PELLET EXTRUSION: CASE STUDY OF THE EXCAVATOR CABIN PRODUCTION

Department of System Design and Control EngineeringIn recent decades, additive manufacturing has begun to impact real industry through significant growth. As the reliability of the final product using AM became higher, the cases applied to the actual production began to appear. In addition, as DfAM, a methodology for understanding the characteristics of AM and exploiting its advantages, has emerged, products with high functionality have been produced without penalties of cost and time. However, there are many problem that should be solved ultimately in order to be utilized in the real industry. Generally, AM is that it requires a closed space for the process and size of final part determined by AM machine. Products with more than size of unit meter are difficult to make with regular AM equipment. In order to make a large sized-products, at the design stage, additional processes are needed to fragment the original part, and is added assembly process. It can also take few hours to several days to build up a fully part located batch of AM. Therefore, AM technology needs a solution to rapidly produce large-sized products that are being produced in the real industry. As presented in this research, Large Object Additive Manufacturing (LOAM) can be a solution to this problem. Large Object Additive Manufacturing can stack several kilograms of material per hour on a large bed with meter units. This paper describes a large object additive manufacturing method, which is a feasible method for making large sized-products with fast fabricating speed. And propose a method to apply LOAM to DfAM which is a design technique that takes maximum advantage of 3D printer. In addition, a case study demonstrates the method of manufacturing the actual industrial excavator cabin using LOAM. A prototyping plan for the 3D printed excavator cabin is described and a design method is proposed to secure the structural safety through the topology optimization method. Adjustment methods are explained to produce successful 3D printing results. In this paper also explains how to assemble large parts made of polymers. Finally, 3D printed excavator cabin project is summarized to the AM methodology of large products through DfAM. Furthermore, establish methodology of applying DfAM technology for creating new products.ope

An overview of decision table literature 1982-1995.

This report gives an overview of the literature on decision tables over the past 15 years. As much as possible, for each reference, an author supplied abstract, a number of keywords and a classification are provided. In some cases own comments are added. The purpose of these comments is to show where, how and why decision tables are used. The literature is classified according to application area, theoretical versus practical character, year of publication, country or origin (not necessarily country of publication) and the language of the document. After a description of the scope of the interview, classification results and the classification by topic are presented. The main body of the paper is the ordered list of publications with abstract, classification and comments.

Advanced Sheet Metal Manufacturing using Rapid Tooling 522

A closed loop process is proposed for making sheet metal prototyping parts by using advanced computer aided techniques and computer controlled machines. The key aspect of this process is the method used to fabricate and modify the sheet metal forming tools, which are not necessarily for mass production but should be suitable for short run production or design evaluation of sheet metal products where the prototyping cost and lead-time are greatly reduced. Various approaches are investigated in the preparation of the tooling for onward embossing on a sheet metal. The three indirect approaches use Selective Laser Sintering (SLS), Stereolithography(SLA), and high speed Computer Numerical Controlled (CNC) milling to build the masters from computer data models. And the masters are then served in the vacuum casting process to generate the non-ferrous tooling. The direct approach uses DTM’s RapidSteel to produce the metal tooling without going through any secondary process. Comparisons on quality, leading time and cost are presented.Mechanical Engineerin

A test case generation framework based on UML statechart diagram

Early software fault detection offers more flexibility to correct errors in the early development stages. Unfortunately, existing studies in this domain are not sufficiently comprehensive in describing the major processes of the automated test case generation. Furthermore, the algorithms used for test case generation are not provided or well described. Current studies also hardly address loops and parallel paths issues, and achieved low coverage criteria. Therefore, this study proposes a test case generation framework that generates minimized and prioritized test cases from UML statechart diagram with higher coverage criteria. This study, conducted a review of the previous research to identify the issues and gaps related to test case generation, model-based testing, and coverage criteria. The proposed framework was designed from the gathered information based on the reviews and consists of eight components that represent a comprehensive test case generation processes. They are relation table, relation graph, consistency checking, test path minimization, test path prioritization, path pruning, test path generation, and test case generation. In addition, a prototype to implement the framework was developed. The evaluation of the framework was conducted in three phases: prototyping, comparison with previous studies, and expert review. The results reveal that the most suitable coverage criteria for UML statechart diagram are all-states coverage, all-transitions coverage, alltransition-pairs coverage, and all-loop-free-paths coverage. Furthermore, this study achieves higher coverage criteria in all coverage criteria, except for all-state coverage, when compared with the previous studies. The results of the experts’ review show that the framework is practical, easy to implement due to it is suitability to generate the test cases. The proposed algorithms provide correct results, and the prototype is able to generate test case effectively. Generally, the proposed system is well accepted by experts owing to its usefulness, usability, and accuracy. This study contributes to both theory and practice by providing an early alternative test case generation framework that achieves high coverage and can effectively generate test cases from UML statechart diagrams. This research adds new knowledge to the software testing field, especially for testing processes in the model-based techniques, testing activity, and testing tool support