WIT transactions on engineering sciences, Oct 14, 2005
Quantitative understanding of frictional phenomena between the tool and the workpiece is essentia... more Quantitative understanding of frictional phenomena between the tool and the workpiece is essential for accurate modeling of the Friction Stir Welding (FSW) process. A method of measuring the tool-workpiece interface is proposed that allows frictional measurements to be made in a non-oxidizing environment under extreme conditions. The ranges of temperature, velocity and normal force are 100-600 • C, 75-400 surface feet per minute, and 100-600 lbf, respectively. Data is gathered at different parameter level combinations to provide enough data to create an empirical model representing the data. Two different friction modes are observed which have distinct characteristics. One mode, Coulomb friction, has frictional force proportional to normal force while the other, plastic shear deformation friction, has frictional force independent of normal force. A linear statistical model has been developed to characterize each of the frictional modes for the Polycrystalline Cubic Boron Nitride (PCBN) tool and 1018 steel work piece interface as functions of temperature, velocity, and normal force.
<jats:title>Abstract</jats:title> <jats:p>To achieve superior product and proce... more <jats:title>Abstract</jats:title> <jats:p>To achieve superior product and process designs with "typical" engineering students requires careful attention to the design process that is taught and the teaching methods to be followed. The Integrated Product and Process Design (or Capstone) program at BYU has applied both. The Capstone program has been in operation for four years, with over 300 students having been through the program, and over 60 projects sponsored by industry.</jats:p> <jats:p>The design process taught in Capstone starts with a rapid cycle through to preliminary concept selection. The process is then repeated, starting with the development of a functional specification, which is followed by formalized concept generation and selection methods, layout and detailed part design using solid modelers, experimental and analytical methods for answering design questions, simultaneous part and manufacturing process design, prototype, and production sample. This design process includes a high degree of concurrent involvement from each of the disciplines on the project team.</jats:p> <jats:p>Non-traditional teaching methods that have proven useful in the class include the use of an industrial paradigm for the educational experience, the use of faculty coaches to mentor the student teams, the use of projects sponsored by industry with regular feedback from the industrial customer, just-in-time education so that students can see immediate application of what is taught, the use of skits and role-playing to teach interpersonal skills, and specific activities that help in the production of project deliverables.</jats:p> <jats:p>The use of this design process and these teaching methods has led to successful design education. Students, faculty, and industrial customers have all been pleased with the success of the Capstone program in producing superior design engineers.</jats:p>
<jats:title>Abstract</jats:title> <jats:p>Most engineering design is performed ... more <jats:title>Abstract</jats:title> <jats:p>Most engineering design is performed by teams. Team formation from a pool of competent designers and engineers is an important factor in helping determine performance potential. This paper is proposes a framework that we have developed to help guide research, and highlights challenges and obstacles that must be addressed in order to improve results in team formation research. A basic framework is presented and used as a basis for reviewing past work in team formation studies. This framework is then expanded to include explicit decisions about team formation and experimental strategy. Three important aspects of the framework that are critical to obtaining significant results about team formation are discussed: experimental strategy, success measures, and the separation of team formation effects from environmental effects. Recommendations for improvement in these areas are presented.</jats:p>
The initial phases of the design process — including interactions with stakeholders, ideation of ... more The initial phases of the design process — including interactions with stakeholders, ideation of concept candidates, and the selection of the best candidates — have a large impact on the success of a project as a whole. They also tend to be the most unstructured portion of the project, and are often marginalized by teams who assume they already understand stakeholder needs and the best solution paths to pursue. Design researchers have developed methods shown to increase the creativity and divergent thinking of the design team during these initial phases of design. Nevertheless, these methods often rely on only a vague or amorphous representation of the design space (the set of all possible concepts the design team could feasibly select to meet the objective of the project). In this paper, we introduce a particular design-space structure that can help teams ideate and evaluate their ideation, thus improving the early phases of the design process. The design space presented here is a ...
Science and Technology of Welding and Joining, 2021
Friction welding (FW) enables joining of dissimilar metals parts up to the limits of their streng... more Friction welding (FW) enables joining of dissimilar metals parts up to the limits of their strength. CostE and NFA are two high-temperature steel alloys used in land-based power generation. These alloys were joined with FW, and the effect of process parameters on post-welded structure and tensile strength was studied. Weld energy primarily determined the heat-affected zone (HAZ) thickness in both alloys. The highest joint efficiencies – up to 96% – resulted from contact strengthening of thin NFA HAZ regions, but too thin of a HAZ resulted in an unreliable joint. Conversely, thick HAZ regions consistently lowered the weld strength. Optimal welding conditions occur with sufficient energy to create a full bond but not so much to notably lower weld strength.
The nature of product modeling systems and related application programs for design and manufactur... more The nature of product modeling systems and related application programs for design and manufacture makes it difficult to integrate them into a consistent and dynamic environment. This has been especially true for rule-based application programs. Through the use of standardized functional interfaces and UNIX interprocess communication, an environment has been developed that allows modelers and application programs to behave like objects within the integration environment. Each modeler and application (objects in the system) runs as a separate process. Each object has specific methods associated with it and also incorporates the concepts of data hiding and encapsulation. The object-oriented approach creates an environment that is service oriented vs. the traditional data-oriented approach. The software that creates and controls this environment is called the Information Services Exchange (ISX). ISX is currently being used to implement a project sponsored by Computer Aided Manufacturing-International (CAM-I) aimed at integrating a wide range of product development software. The approach developed within ISX could have a significant effect on design of diverse and large-scale product development systems.
Prerequisite Knowledge Required Students should probably have completed high school, although thi... more Prerequisite Knowledge Required Students should probably have completed high school, although this is feasible for advanced high school students. The concepts of surface energy and surface tension should have been explained. Students should be taught how to do a force balance on a hemispherical bubble, with the pressure inside the bubble balanced by the surface tension force at the equator of the bubble. Objectives * Students will gain an understanding of surface tension. * Students will see that the pressure inside a small bubble is larger than that inside a large bubble.
Frequent and effective design evaluation is foundational to the success of any product developmen... more Frequent and effective design evaluation is foundational to the success of any product development effort. Products that will be used, installed, or otherwise handled by humans would benefit from both an evaluation of the product itself (the physical embodiment of the technology, termed technology), and the steps a user should take to use that technology (termed tactics). Current methods for the evaluation of tactics are scattered across multiple research areas, and are often inaccessible to engineers who have no prior experience with them. Furthermore, the existing tactics evaluation methods often focus mostly on the use of a product and do not simultaneously consider technological performance. In this paper we present a method for the simultaneous evaluation of tactics and technology during the conceptual design stage. To achieve this, we propose three contributions; an approach for representing tactics concepts, a set of criteria for tactics evaluations, and a means for presentin...
Demand is increasing for effective online tools to perform collaborative engineering design by ge... more Demand is increasing for effective online tools to perform collaborative engineering design by geographically separated teams. In particular, tools that facilitate the concept ideation phase of the engineering design process are sought for immediate implementation in product design. In this work, researchers conducted a literature review, interviews with practicing engineers, and a thorough web search to identify available tools and the desired features and requirements. A set of 100 web-based collaborative tools were identified then filtered down to 18 candidates which met the minimum criteria. These 18 were systematically evaluated by the researchers who rated their satisfaction of 11 requirements. The five highest rated finalist platforms were more thoroughly tested by design teams who used the platforms in design sprint activities. Evaluator ratings and feedback were collected at multiple points and several best practices were discovered during testing. Conceptboard3 received th...
Volume 3: 21st International Conference on Advanced Vehicle Technologies; 16th International Conference on Design Education, 2019
Student capstone teams have varying degrees of success in meeting the expectations of their proje... more Student capstone teams have varying degrees of success in meeting the expectations of their project sponsors. Keeping sponsors happy is important to these programs in order to ensure continued support from these industry representatives, so finding ways to improve project outcomes is critical. In order to find blind spots that students may have been left with after their first 6–7 weeks of instruction, we conducted structured interviews with students in capstone programs at Brigham Young University and the US Air Force Academy. These interviews were then transcribed, coded, and analyzed for themes that may have been well understood or misunderstood by students. We found that a significant number of students had not understood concepts such as a design being more than a prototype, that sponsors have expectations for the tradeoffs between product cost and performance, or that they need to be thinking about how their designs might be deployed. It was also interesting to note that most ...
This paper describes a new strategy for incorporating tolerances as part of engineering design op... more This paper describes a new strategy for incorporating tolerances as part of engineering design optimization. The tolerance problem is defined in a general way that allows for tolerances on all model variables and parameters and includes worst case and statistical analysis. Two methods are described for taking tolerances into account during optimization such that an optimal design will remain feasible despite fluctuations in variables or parameters. Methods are also presented for directly controlling transmitted variation, and a framework for optimal tolerance allocation is proposed.
Teaching engineering design through senior project or capstone engineering courses has increased ... more Teaching engineering design through senior project or capstone engineering courses has increased in recent years. The trend toward increasing the design component in engineering curricula is part of an effort to better prepare graduates for engineering practice. This paper describes the standard practices and current state of capstone design education throughout the country as revealed through a literature search of over 100 papers relating to engineering design courses. Major topics include the development of capstone design courses, course descriptions, project information, details of industrial involvement, and special aspects of teamoriented design projects. An extensive list of references is provided. I. INTRODUCTION Recent trends in engineering education have led to an increased use of class projects for teaching engineering design. Senior-level capstone design courses have become increasingly popular among many engineering educators. Capstone courses in nearly every d...
While both subjective measures and quantitative metrics play an important role in admissions deci... more While both subjective measures and quantitative metrics play an important role in admissions decisions, quantitative metrics are amenable to critical analysis using the tools of academic analytics. The hypotheses that motivated this study are: 1. Can an applicant's undergraduate grade point average (UGPA) and scores on the Graduate Records Examinations (GRE) be used to accurately predict the performance of the applicant in a graduate mechanical engineering program? 2. Is a single construct based on these quantitative predictive metrics a valuable tool in efficiently making admissions decisions? This study analyzed the relationship between quantitative predictive metrics, available at the time of application to a mechanical engineering graduate program, and quantitative performance assessments measured at the thesis defense. The sample includes 92 students graduating with MS degrees in mechanical engineering from a private university in the United States. The input variables include UGPA, and percentiles for the verbal, quantitative, and written sections of the GRE. The performance metrics were obtained at the thesis defense. They are graduate grade point average, months to graduation, peer-review publication rating, and advisor determined performance rating. Each variable was normalized and the relationship between the predictive metrics and the performance metrics was analyzed statistically. Regression models were created for each performance metric and for a weighted sum of all the performance metrics. The dominant predictors are the UGPA and the score on the quantitative section of the GRE. A quantitative application rating is found to be 5 times the normalized UGPA plus four times the normalized score on the quantitative section of the GRE. Quantitative metrics account for one fifth of the variance in the performance metrics. The Quantitative Application Rating-a single construct based on the quantitative predictive metrics studied-aids in making admissions decisions.
It is sometimes forgotten that industry is an important customer of engineering education. Ignori... more It is sometimes forgotten that industry is an important customer of engineering education. Ignoring this relationship has produced graduates that often fail to meet the changing needs of industry in todays competitive environment. On the basis of feedback from our industrial customers, faculty from Mechanical Engineering and Manufacturing Engineering at Brigham Young University have jointly developed a new senior capstone design course entitled Integrated Product and Process Design. This new capstone course is centered on industrial design and manufacturing projects. These projects involve both product and process design activities. Multidisciplinary teams of students are taught a structured development approach to produce typical industrial deliverables. These deliverables include a functional specification, product and process design, prototype, and first production sample. This paper identifies changing industrial needs, describes how the course was designed to meet these needs, and presents results from the initial offerings of the course.
... Such courses provide an experiential learning activity in which the analytical knowledge gain... more ... Such courses provide an experiential learning activity in which the analytical knowledge gained from previous courses is joined with the practice of engi-neering in a final, hands-onproject.5,6 The development of capstone design courses has been influenced by many sources ...
Friction stir welding (FSW) is an advantageous solid-state joining process that is suitable for m... more Friction stir welding (FSW) is an advantageous solid-state joining process that is suitable for many materials in multiple industries. In an industrial setting, manufacturers are actively seeking faster welding speeds to increase throughput. Increasing welding speed limits the size of defect-free parameter windows, which may increase the frequency of defects. The push for faster welding speeds emphasizes the need for economical non-destructive evaluation (NDE) for FSW, like any other type of welding. This work introduces a generalized defect detection method that recognizes the stochastic nature of the FSW process, and that can be generally applied to FSW of a material across a dynamic range of process parameters and welding conditions. When applied to aluminum friction stir-welded blanks at speeds ranging from 1500 to 3000 mm/min with varying ranges of tool tilts, the methodology proved 100% effective at positive detection when defects were present with zero scrap rate. Furthermore...
Geometric feature variations are the result of variations in the shape, orientation or location o... more Geometric feature variations are the result of variations in the shape, orientation or location of part features as defined in ANSI Y14.5M-1982 tolerance standard [ANSI 1982]. When such feature variations occur on the mating surfaces between components of an assembly, they affect the variation of the completed assembly. The geometric feature variations accumulate statistically and propagate kinematically in a similar manner to the dimensional variations of the components in the assembly. The Direct Linearization Method (DLM) for assembly tolerance analysis provides a method for estimating variations and assembly rejects, caused by the dimensional variations of the components in an assembly. So far, no generalized approach has been developed to include all geometric feature variations in a computer-aided tolerance analysis system. This paper introduces a new, generalized approach for including all the geometric feature variations in the tolerance analysis of mechanical assemblies. It focuses on how to characterize geometric feature variations in vector-loop-based assembly tolerance models. The characterization will be used to help combine the effects of all variations within an assembly in order to predict assembly rejects using the DLM.
WIT transactions on engineering sciences, Oct 14, 2005
Quantitative understanding of frictional phenomena between the tool and the workpiece is essentia... more Quantitative understanding of frictional phenomena between the tool and the workpiece is essential for accurate modeling of the Friction Stir Welding (FSW) process. A method of measuring the tool-workpiece interface is proposed that allows frictional measurements to be made in a non-oxidizing environment under extreme conditions. The ranges of temperature, velocity and normal force are 100-600 • C, 75-400 surface feet per minute, and 100-600 lbf, respectively. Data is gathered at different parameter level combinations to provide enough data to create an empirical model representing the data. Two different friction modes are observed which have distinct characteristics. One mode, Coulomb friction, has frictional force proportional to normal force while the other, plastic shear deformation friction, has frictional force independent of normal force. A linear statistical model has been developed to characterize each of the frictional modes for the Polycrystalline Cubic Boron Nitride (PCBN) tool and 1018 steel work piece interface as functions of temperature, velocity, and normal force.
<jats:title>Abstract</jats:title> <jats:p>To achieve superior product and proce... more <jats:title>Abstract</jats:title> <jats:p>To achieve superior product and process designs with "typical" engineering students requires careful attention to the design process that is taught and the teaching methods to be followed. The Integrated Product and Process Design (or Capstone) program at BYU has applied both. The Capstone program has been in operation for four years, with over 300 students having been through the program, and over 60 projects sponsored by industry.</jats:p> <jats:p>The design process taught in Capstone starts with a rapid cycle through to preliminary concept selection. The process is then repeated, starting with the development of a functional specification, which is followed by formalized concept generation and selection methods, layout and detailed part design using solid modelers, experimental and analytical methods for answering design questions, simultaneous part and manufacturing process design, prototype, and production sample. This design process includes a high degree of concurrent involvement from each of the disciplines on the project team.</jats:p> <jats:p>Non-traditional teaching methods that have proven useful in the class include the use of an industrial paradigm for the educational experience, the use of faculty coaches to mentor the student teams, the use of projects sponsored by industry with regular feedback from the industrial customer, just-in-time education so that students can see immediate application of what is taught, the use of skits and role-playing to teach interpersonal skills, and specific activities that help in the production of project deliverables.</jats:p> <jats:p>The use of this design process and these teaching methods has led to successful design education. Students, faculty, and industrial customers have all been pleased with the success of the Capstone program in producing superior design engineers.</jats:p>
<jats:title>Abstract</jats:title> <jats:p>Most engineering design is performed ... more <jats:title>Abstract</jats:title> <jats:p>Most engineering design is performed by teams. Team formation from a pool of competent designers and engineers is an important factor in helping determine performance potential. This paper is proposes a framework that we have developed to help guide research, and highlights challenges and obstacles that must be addressed in order to improve results in team formation research. A basic framework is presented and used as a basis for reviewing past work in team formation studies. This framework is then expanded to include explicit decisions about team formation and experimental strategy. Three important aspects of the framework that are critical to obtaining significant results about team formation are discussed: experimental strategy, success measures, and the separation of team formation effects from environmental effects. Recommendations for improvement in these areas are presented.</jats:p>
The initial phases of the design process — including interactions with stakeholders, ideation of ... more The initial phases of the design process — including interactions with stakeholders, ideation of concept candidates, and the selection of the best candidates — have a large impact on the success of a project as a whole. They also tend to be the most unstructured portion of the project, and are often marginalized by teams who assume they already understand stakeholder needs and the best solution paths to pursue. Design researchers have developed methods shown to increase the creativity and divergent thinking of the design team during these initial phases of design. Nevertheless, these methods often rely on only a vague or amorphous representation of the design space (the set of all possible concepts the design team could feasibly select to meet the objective of the project). In this paper, we introduce a particular design-space structure that can help teams ideate and evaluate their ideation, thus improving the early phases of the design process. The design space presented here is a ...
Science and Technology of Welding and Joining, 2021
Friction welding (FW) enables joining of dissimilar metals parts up to the limits of their streng... more Friction welding (FW) enables joining of dissimilar metals parts up to the limits of their strength. CostE and NFA are two high-temperature steel alloys used in land-based power generation. These alloys were joined with FW, and the effect of process parameters on post-welded structure and tensile strength was studied. Weld energy primarily determined the heat-affected zone (HAZ) thickness in both alloys. The highest joint efficiencies – up to 96% – resulted from contact strengthening of thin NFA HAZ regions, but too thin of a HAZ resulted in an unreliable joint. Conversely, thick HAZ regions consistently lowered the weld strength. Optimal welding conditions occur with sufficient energy to create a full bond but not so much to notably lower weld strength.
The nature of product modeling systems and related application programs for design and manufactur... more The nature of product modeling systems and related application programs for design and manufacture makes it difficult to integrate them into a consistent and dynamic environment. This has been especially true for rule-based application programs. Through the use of standardized functional interfaces and UNIX interprocess communication, an environment has been developed that allows modelers and application programs to behave like objects within the integration environment. Each modeler and application (objects in the system) runs as a separate process. Each object has specific methods associated with it and also incorporates the concepts of data hiding and encapsulation. The object-oriented approach creates an environment that is service oriented vs. the traditional data-oriented approach. The software that creates and controls this environment is called the Information Services Exchange (ISX). ISX is currently being used to implement a project sponsored by Computer Aided Manufacturing-International (CAM-I) aimed at integrating a wide range of product development software. The approach developed within ISX could have a significant effect on design of diverse and large-scale product development systems.
Prerequisite Knowledge Required Students should probably have completed high school, although thi... more Prerequisite Knowledge Required Students should probably have completed high school, although this is feasible for advanced high school students. The concepts of surface energy and surface tension should have been explained. Students should be taught how to do a force balance on a hemispherical bubble, with the pressure inside the bubble balanced by the surface tension force at the equator of the bubble. Objectives * Students will gain an understanding of surface tension. * Students will see that the pressure inside a small bubble is larger than that inside a large bubble.
Frequent and effective design evaluation is foundational to the success of any product developmen... more Frequent and effective design evaluation is foundational to the success of any product development effort. Products that will be used, installed, or otherwise handled by humans would benefit from both an evaluation of the product itself (the physical embodiment of the technology, termed technology), and the steps a user should take to use that technology (termed tactics). Current methods for the evaluation of tactics are scattered across multiple research areas, and are often inaccessible to engineers who have no prior experience with them. Furthermore, the existing tactics evaluation methods often focus mostly on the use of a product and do not simultaneously consider technological performance. In this paper we present a method for the simultaneous evaluation of tactics and technology during the conceptual design stage. To achieve this, we propose three contributions; an approach for representing tactics concepts, a set of criteria for tactics evaluations, and a means for presentin...
Demand is increasing for effective online tools to perform collaborative engineering design by ge... more Demand is increasing for effective online tools to perform collaborative engineering design by geographically separated teams. In particular, tools that facilitate the concept ideation phase of the engineering design process are sought for immediate implementation in product design. In this work, researchers conducted a literature review, interviews with practicing engineers, and a thorough web search to identify available tools and the desired features and requirements. A set of 100 web-based collaborative tools were identified then filtered down to 18 candidates which met the minimum criteria. These 18 were systematically evaluated by the researchers who rated their satisfaction of 11 requirements. The five highest rated finalist platforms were more thoroughly tested by design teams who used the platforms in design sprint activities. Evaluator ratings and feedback were collected at multiple points and several best practices were discovered during testing. Conceptboard3 received th...
Volume 3: 21st International Conference on Advanced Vehicle Technologies; 16th International Conference on Design Education, 2019
Student capstone teams have varying degrees of success in meeting the expectations of their proje... more Student capstone teams have varying degrees of success in meeting the expectations of their project sponsors. Keeping sponsors happy is important to these programs in order to ensure continued support from these industry representatives, so finding ways to improve project outcomes is critical. In order to find blind spots that students may have been left with after their first 6–7 weeks of instruction, we conducted structured interviews with students in capstone programs at Brigham Young University and the US Air Force Academy. These interviews were then transcribed, coded, and analyzed for themes that may have been well understood or misunderstood by students. We found that a significant number of students had not understood concepts such as a design being more than a prototype, that sponsors have expectations for the tradeoffs between product cost and performance, or that they need to be thinking about how their designs might be deployed. It was also interesting to note that most ...
This paper describes a new strategy for incorporating tolerances as part of engineering design op... more This paper describes a new strategy for incorporating tolerances as part of engineering design optimization. The tolerance problem is defined in a general way that allows for tolerances on all model variables and parameters and includes worst case and statistical analysis. Two methods are described for taking tolerances into account during optimization such that an optimal design will remain feasible despite fluctuations in variables or parameters. Methods are also presented for directly controlling transmitted variation, and a framework for optimal tolerance allocation is proposed.
Teaching engineering design through senior project or capstone engineering courses has increased ... more Teaching engineering design through senior project or capstone engineering courses has increased in recent years. The trend toward increasing the design component in engineering curricula is part of an effort to better prepare graduates for engineering practice. This paper describes the standard practices and current state of capstone design education throughout the country as revealed through a literature search of over 100 papers relating to engineering design courses. Major topics include the development of capstone design courses, course descriptions, project information, details of industrial involvement, and special aspects of teamoriented design projects. An extensive list of references is provided. I. INTRODUCTION Recent trends in engineering education have led to an increased use of class projects for teaching engineering design. Senior-level capstone design courses have become increasingly popular among many engineering educators. Capstone courses in nearly every d...
While both subjective measures and quantitative metrics play an important role in admissions deci... more While both subjective measures and quantitative metrics play an important role in admissions decisions, quantitative metrics are amenable to critical analysis using the tools of academic analytics. The hypotheses that motivated this study are: 1. Can an applicant's undergraduate grade point average (UGPA) and scores on the Graduate Records Examinations (GRE) be used to accurately predict the performance of the applicant in a graduate mechanical engineering program? 2. Is a single construct based on these quantitative predictive metrics a valuable tool in efficiently making admissions decisions? This study analyzed the relationship between quantitative predictive metrics, available at the time of application to a mechanical engineering graduate program, and quantitative performance assessments measured at the thesis defense. The sample includes 92 students graduating with MS degrees in mechanical engineering from a private university in the United States. The input variables include UGPA, and percentiles for the verbal, quantitative, and written sections of the GRE. The performance metrics were obtained at the thesis defense. They are graduate grade point average, months to graduation, peer-review publication rating, and advisor determined performance rating. Each variable was normalized and the relationship between the predictive metrics and the performance metrics was analyzed statistically. Regression models were created for each performance metric and for a weighted sum of all the performance metrics. The dominant predictors are the UGPA and the score on the quantitative section of the GRE. A quantitative application rating is found to be 5 times the normalized UGPA plus four times the normalized score on the quantitative section of the GRE. Quantitative metrics account for one fifth of the variance in the performance metrics. The Quantitative Application Rating-a single construct based on the quantitative predictive metrics studied-aids in making admissions decisions.
It is sometimes forgotten that industry is an important customer of engineering education. Ignori... more It is sometimes forgotten that industry is an important customer of engineering education. Ignoring this relationship has produced graduates that often fail to meet the changing needs of industry in todays competitive environment. On the basis of feedback from our industrial customers, faculty from Mechanical Engineering and Manufacturing Engineering at Brigham Young University have jointly developed a new senior capstone design course entitled Integrated Product and Process Design. This new capstone course is centered on industrial design and manufacturing projects. These projects involve both product and process design activities. Multidisciplinary teams of students are taught a structured development approach to produce typical industrial deliverables. These deliverables include a functional specification, product and process design, prototype, and first production sample. This paper identifies changing industrial needs, describes how the course was designed to meet these needs, and presents results from the initial offerings of the course.
... Such courses provide an experiential learning activity in which the analytical knowledge gain... more ... Such courses provide an experiential learning activity in which the analytical knowledge gained from previous courses is joined with the practice of engi-neering in a final, hands-onproject.5,6 The development of capstone design courses has been influenced by many sources ...
Friction stir welding (FSW) is an advantageous solid-state joining process that is suitable for m... more Friction stir welding (FSW) is an advantageous solid-state joining process that is suitable for many materials in multiple industries. In an industrial setting, manufacturers are actively seeking faster welding speeds to increase throughput. Increasing welding speed limits the size of defect-free parameter windows, which may increase the frequency of defects. The push for faster welding speeds emphasizes the need for economical non-destructive evaluation (NDE) for FSW, like any other type of welding. This work introduces a generalized defect detection method that recognizes the stochastic nature of the FSW process, and that can be generally applied to FSW of a material across a dynamic range of process parameters and welding conditions. When applied to aluminum friction stir-welded blanks at speeds ranging from 1500 to 3000 mm/min with varying ranges of tool tilts, the methodology proved 100% effective at positive detection when defects were present with zero scrap rate. Furthermore...
Geometric feature variations are the result of variations in the shape, orientation or location o... more Geometric feature variations are the result of variations in the shape, orientation or location of part features as defined in ANSI Y14.5M-1982 tolerance standard [ANSI 1982]. When such feature variations occur on the mating surfaces between components of an assembly, they affect the variation of the completed assembly. The geometric feature variations accumulate statistically and propagate kinematically in a similar manner to the dimensional variations of the components in the assembly. The Direct Linearization Method (DLM) for assembly tolerance analysis provides a method for estimating variations and assembly rejects, caused by the dimensional variations of the components in an assembly. So far, no generalized approach has been developed to include all geometric feature variations in a computer-aided tolerance analysis system. This paper introduces a new, generalized approach for including all the geometric feature variations in the tolerance analysis of mechanical assemblies. It focuses on how to characterize geometric feature variations in vector-loop-based assembly tolerance models. The characterization will be used to help combine the effects of all variations within an assembly in order to predict assembly rejects using the DLM.
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Papers by Carl Sorensen