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Abstract Skeletal fixation plates are essential components in craniomaxillofacial (CMF) reconstructive surgery to connect skeletal disunions. To ensure that these plates achieve geometric conformity to the CMF skeleton of individual patients, a pre-operative procedure involving manual plate bending is traditionally required. However, manual adjustment of the fixation plate can be time-consuming and is prone to geometric error due to the springback effect and human inspection limitations. This work represents a first step towards autonomous incremental plate bending for CMF reconstructive surgery through machine learning-enabled springback prediction and feedback bending control. Specifically, a Gaussian process is first investigated to complement the physics-based Gardiner equation to improve the accuracy of springback effect estimation, which is then incorporated into nonlinear model predictive controller to determine the optimal sequence of bending inputs to achieve geometric conformity. Evaluation using a simulated environment for bending confirms the effectiveness of the developed approach. 

This study demonstrates that the thickness of the target and its backing condition have a powerful effect on the development of a wave structure in impact welds. Conventional theories and experiments related to impact welds show that the impact angle and speed of the flyer have a controlling influence on the development of wave structure and jetting. These results imply that control of reflected stress waves can be effectively used to optimize welding conditions and expand the range of acceptable collision angle and speed for good welding. Impact welding and laser impact welding are a class of processes that can create solid-state welds, permitting the formation of strong and tough welds without the creation of significant heat affected zones, and can avoid the gross formation of intermetallic in dissimilar metal pairs. This study examined small-scale impact using a consistent launch condition for a 127 µm commercially pure titanium flyer impacted against commercially pure copper target with thicknesses between 127 µm and 1000 µm. Steel and acrylic backing layers were placed behind the target to change wave reflection characteristics. The launch conditions produced normal collision at about 900 m/s at the weld center, with decreasing impact speed and increasing angle moving toward the outer perimeter. The target thickness had a large effect on wave morphology, with the wave amplitude increasing with target thickness in both cases, peaking when target thickness is about twice flyer thickness, and then falling. The acrylic backing showed a consistently smaller unwelded central zone, indicating that impact welding is possible at a smaller angle in that case. Strength was measured in destructive tensile testing. Failure was controlled by the breakdown of the weaker of the two base metals over all thicknesses and backings. This demonstrates that laser impact welding is a robust method for joining dissimilar metals over a range of thicknesses. 

Abstract Over the last few decades, globalization has weakened the US manufacturing sector. The COVID-19 pandemic revealed import dependencies and supply chain shocks that have raised public and private awareness of the need to rebuild domestic production. A range of new technologies, collectively called Industry 4.0, create opportunities to revolutionize domestic and local manufacturing. Success depends on further refinement of those technologies, broad implementation throughout private companies, and concerted efforts to rebuild the industrial commons, the national ecosystem of producers, suppliers, service providers, educators, and workforce necessary to regain a competitive, innovative manufacturing sector. A recent workshop sponsored by the Engineering Research Visioning Alliance (ERVA) identified a range of challenges and opportunities to build a resilient, flexible, scalable, and high-quality manufacturing sector. This paper provides a strategic roadmap for regaining US manufacturing leadership by briefly summarizing discussions at the ERVA-sponsored workshop held in 2023 and providing additional analysis of key technical and economic issues that must be addressed to achieve dynamic, high-value manufacturing in the USA. The focus of this presentation is on discrete manufacturing of production of structural components, a large subset of total manufacturing that produces high-value inputs and finished products for domestic consumption and export. 

Abstract The mass reduction of passenger vehicles has been a great focus of academic research and federal policy initiatives of the United States with coordinated funding efforts and even a focus of a Manufacturing USA Institute. The potential benefit of these programs can be described as modest from a societal point of view, for example reducing vehicle mass by up to 25% with modest cost implications (under $5 per pound saved) and the ability to implement with existing manufacturing methods. Much more aggressive reductions in greenhouse gas production are necessary and possible, while delivering the same service. This is demonstrated with a higher-level design thinking exercise on an environmentally responsible lightweight vehicle, leading to the following criteria: lightweight, low aerodynamic drag, long-lived (over 30 years and 2 million miles), adaptable, electric, and used in a shared manner on average over 8 h per day. With these specifications, passenger-mile demand may be met with around 1/10 of the current fleet. Such vehicles would likely have significantly different designs and construction than incumbent automobiles. It is likely future automotive production will be more analogous to current aircraft production with higher costs per pound and lower volumes, but with dramatically reduced financial and environmental cost per passenger mile, with less material per vehicle, and far less material required in the national or worldwide fleets. Subsidiary benefits of this vision include far fewer parking lots, greater accessibility to personal transportation, and improved pedestrian safety, while maintaining a vibrant and engaging economy. The systemic changes to the business models and research and development directions (including lightweight design and manufacturing) are discussed, which could bring forth far more sustainable personal transportation.