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Redesigning Products To Optimize Sustainable Performance In Multi-Generational Closed-Loop Production For Advancing The Circular Economy, Buddhika Minendra Hapuwatte

Theses and Dissertations--Mechanical Engineering

Sustainable manufacturing and the circular economy concepts promote efficient and effective resource use to minimize the adverse economic, environmental, and social impacts of alarmingly increasing consumption rates. Product design is the key to implement these transformations in manufacturing. However, the currently available sustainable and circular design methods are not comprehensive and inadequate—especially for multi-generational products. Therefore, designing sustainable products optimized for circular and closed-loop production systems is a challenging task. The 6Rs concept introduced ‘Redesign’ to modify a product’s engineering specifications and allow sustainable utilization of the end-of-use resources from previous generations, thus closing the production loop. Therefore, the objective …

Transforming A Circular Economy Into A Helical Economy For Advancing Sustainable Manufacturing, Ryan T. Bradley

Theses and Dissertations--Mechanical Engineering

The U.N. projects the world population to reach nearly 10 billion people by 2050, which will cause demand for manufactured goods to reach unforeseen levels. In order for us to produce the goods to support an equitable future, the methods in which we manufacture those goods must radically change. The emerging Circular Economy (CE) concept for production systems has promised to drastically increase economic/business value by significantly reducing the world’s resource consumption and negative environmental impacts. However, CE is inherently limited because of its emphasis on recycling and reuse of materials. CE does not address the holistic changes needed across …

Energy Resources Use Metrics, Rahul Y. Nehete

Theses and Dissertations--Mechanical Engineering

Energy resources use has been considered as a key component of sustainable development. Data related to global, regional, state, sector, industry and process demonstrate that a significant reduction of energy resources for a given production rate in manufacturing processes requires an introduction of transformational technologies at the process level, propagating the impact to higher scales, leading not just to a gradual improvement of traditional technologies but to more sustainable development.

The study offers two approaches to the formulation of the limits of energy use in the context of sustainable development. The first is to construct a map of key selected …

A Framework For Sustainable Material Selection For Multi-Generational Components, Ryan T. Bradley

Theses and Dissertations--Mechanical Engineering

The early stages of a product’s design are a critical time for decisions that impact the entire life-cycle cost. Product designers have mastered the first generation; however, they currently do not have the ability to know the impact of their decisions on the multi-generational view. This thesis aims at closing the gap between total life-cycle information and the traditional design process in order to harbor sustainable value creation among all stakeholders involved. A framework is presented that uses a combination of a life-cycle costing methodology and an evolutionary algorithm in order to achieve a sustainability assessment for a true multi-generational …

Combining Sustainable Value Stream Mapping And Simulation To Assess Manufacturing Supply Chain Network Performance, Daniel T. Sparks

Theses and Dissertations--Mechanical Engineering

Sustainable Value Stream Mapping (Sus-VSM) builds upon traditional VSM to capture additional sustainability aspects of the product flow, such as environmental and societal aspects. This work presents research to expand the utility of Sus-VSM to supply chain networks, develop a general approach towards improving supply chain sustainability, and examine the benefits of implementing simulation and a design of experiments (DOE) style analysis. Metrics are identified to assess economic, environmental, and societal sustainability for supply chain networks and visual symbols are developed for the Supply Chain Sus-VSM (SC Sus-VSM) to allow users to easily identify locations where sustainability can be improved. …

A Metrics-Based Sustainability Assessment Of Cryogenic Machining Using Modeling And Optimization Of Process Performance, Tao Lu

Theses and Dissertations--Mechanical Engineering

The development of a sustainable manufacturing process requires a comprehensive evaluation method and fundamental understanding of the processes. Coolant application is a critical sustainability concern in the widely used machining process. Cryogenic machining is considered a candidate for sustainable coolant application. However, the lack of comprehensive evaluation methods leaves significant uncertainties about the overall sustainability performance of cryogenic machining. Also, the lack of practical application guidelines based on scientific understanding of the heat transfer mechanism in cryogenic machining limits the process optimization from achieving the most sustainable performance.

In this dissertation, based on a proposed Process Sustainability Index (ProcSI …