Mechanical Engineering Graduate Seminar Series: Dr. Anthony Spangenberger - Materials-Conscious Design for Structural Integrity with Metal Additive Manufacturing
Abstract: Metal additive manufacturing (AM) is often touted as a revolutionary tool that is changing the design paradigm, offering advantages of reducing materials and energy waste, promoting faster and less expensive small production runs, reducing on-hand inventories, and enabling greater design flexibility. Amid the sensation, mechanical performance is often overlooked, despite being critically important to advancing the use of AM in structurally critical design applications. The most frequent, lifetime-limiting failure mechanism in engineered components is fatigue, the process of initiation and growth of cracks during cyclic loading below the macroscopic yield strength. The relationship between fatigue properties and AM processing parameters is best understood at the mesostructural scale – material microstructure, processing defects, residual stress, and surface roughness – which provide hierarchical linkages for interpreting mechanical behavior and are the focus of this talk. First, experimental studies in various alloys will be discussed to highlight essential process-property-performance relationships that form useful heuristics for design with AM. This knowledge will then be translated into fracture mechanics-driven design tools, S-N and Kitagawa-Takahashi diagrams, which are used for selecting design constraints. Finally, looking to the future of design in AM, computational modeling of microstructure formation and fatigue property prediction will be discussed.
Bio: Dr. Spangenberger is an Assistant Research Professor at WPI. He received his B.S. in Mechanical Engineering (2012) and Ph.D. in Materials Science and Engineering (2017) from WPI. His doctoral research focused on optimization of cast aluminum-silicon alloys used within the automotive sector for fatigue crack growth resistance. Microstructure-scale, extended finite element (XFEM) crack growth models were developed to rapidly simulate crack-microstructure interactions and predict crack growth rates. He currently co-directs the Integrative Materials Design Center (iMdc) at WPI, a university-government-industry alliance that promotes materials-centric design for high-integrity structural applications throughout the manufacturing and transportation sectors. Dr. Spangenberger's research interests include investigation of mechanisms of fatigue crack growth, novel manufacturing and mechanical testing methods, solid mechanics modeling, development of scale-bridging techniques for computational modeling of damage phenomena, and integration of fundamental research with industrial design practices.