A Master of Science thesis in Mechanical Engineering by Jaber Jamal entitled, "Sustainability Assessment of Welding Processes," submitted in May 2017. Thesis advisor is Dr. Basil Darras and thesis co-advisor is Dr. Hossam Kishawy. Soft and hard copy available.
In today's world, calls for 'sustainability' are increasing in order to preserve our resources and our environment. Many initiatives are being put in motion to make our lives more 'sustainable'. This concept of 'sustainability' has recently risen to take the old concept of going 'green' further. To elaborate, where 'green' aimed to preserve the environment and decrease the emissions of greenhouse gases and other harmful substances, 'sustainability' takes the economy and society into consideration. This is done by considering how much money it would cost, how it would affect the society, and how to be more environmentally friendly for a particular product or process. This thesis aims to outline general methodologies for sustainability assessments. This would then be adapted for manufacturing processes, and then would be applied to measure and assess the sustainability of welding processes. The objective is to build a complete framework that would be used to determine the best welding process for a particular application. To apply this methodology, data about the welding processes was collected and segregated into four categories: environmental impact, economic impact, social impact, and physical performance. Each of these categories had a number of indicators which would quantify the performance of each process. This quantification step was done by developing specific equations and applying them to the indicators. An aggregate sustainability score was then obtained from the individual scores of each category. However, to avoid taking the arithmetic average which indicates equal importance for each category, a weighted average was suggested in this thesis. To obtain the respective weights, a survey was created and distributed to experts. The collected results were analyzed and incorporated to calculate the aggregate score. To demonstrate the capability of this methodology, three welding processes, gas tungsten arc welding (GTAW), gas metal arc welding (GMAW), and friction stir welding (FSW) were assessed on welding Aluminum 5083. This would determine the most sustainable process in that particular application. The final outcome showed that FSW was the most sustainable process for the application.