2024 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2024): Topology Optimization for AM
Program Organizers: Joseph Beaman, University of Texas at Austin
Tuesday 1:30 PM
August 13, 2024
Room: 417 AB
Location: Hilton Austin
Session Chair: Kazi Md Masum Billah, University of Houston Clear Lake
1:30 PM
Toolpath Planning for Additively Manufactured Continuous-Fiber Reinforced Composties Designed by Topology Optimization: Janet Wong1; Emily Sanders1; David Rosen2; 1Georgia Institute of Technology; 2Agency for Science, Technology and Research (A*STAR)
Fiber layout of continuous fiber-reinforced composites (CFRCs) designed with topology optimization is typically represented by a discrete vector field that must be translated into continuous toolpaths via a toolpath planning step. Toolpaths should align well with the optimized fiber layout and have equal spacing for optimal structural performance and manufacturability, respectively. We ensure equal toolpath spacing by adopting a projection-based toolpath planning method and promote smoothly-varying fiber orientation by using radial basis functions (RBFs) to describe the fiber angles. RBFs also eliminate the need for post-processing steps typically required to regulate the fiber orientations when using a projection-based method. Finally, we introduce a correlation factor that quantifies how well the toolpaths align to the fiber orientations and optimize parameters of the projection to maximize the correlation. We compare the structural performance and manufacturability of several CFRC designs, post-processed using the projection-based method, to those post-processed using other toolpath planning methods.
1:50 PM
Improve Frames´ Crash-Worthiness with AlSi10Mg Reinforcement Structures by DED-LB/P: Francesco Bruzzo1; Matteo Alberghini2; Andrea Bertinetti2; Alessio Tommasi2; Mirko Riede1; Daniele Pullini3; Elena López1; 1Fraunhofer IWS; 2Gemmate Technologies Srl; 3Centro Ricerche Fiat
DED technologies can be easily integrated in manufacturing chains with conventional technologies. This characteristic can be exploited by designing topology optimized reinforcement onto pre-existing frames to improve their crash-worthiness while keeping the part lightweight. This study focuses on DED-LB/P optimization to manufacture AlSi10Mg reinforcement structures on thin aluminium substrates while preventing excessive thermal deformation. The reinforcement provided to a 1.5 mm thick substrate by a single wall of deposited material, with cross section of 2 x 2.5 mm, was evaluated by 3 points bending tests. With the reinforcement on the tensile side of the stresses, the energy absorbed increased by 2.4%, while with the reinforcement on the compression side of the stresses the increase was 75.8%. Numerical simulations are then calibrated on those results and later used to de-sign topology optimized reinforcements on complex subcomponents to tailor their mechanical behaviour and maximize energy absorption during deformation.
2:10 PM
Size and Shape Optimisation for High-Performance Battery Electrodes: Chikwesiri Imediegwu1; Milo Shaffer1; Mary Ryan1; Ajit Panesar1; 1Imperial College London
Classical lithium-ion battery (LIB) electrodes comprise of a stochastic mixture of active material particles, binder and conductive additives. However, the trade-off between capacity and rate capability is a well-known limitation to the performance of these batteries. This study demonstrates that there are optimal electrode thicknesses and active material volume fractions for different electrode applications. It presents a guide for optimal electrode design and highlights that patterned electrodes can improve battery performance significantly, only limited by manufacturability.
2:30 PM
Topology-Driven Information Embedding in Structural Components: Karim ElSayed1; Andres Tovar1; Jitesh Panchal1; 1Purdue University
Information embedding within manufactured parts is an increasingly important problem that aims to address traceability and counterfeiting. However, existing literature addresses information embedding independently of part's functional performance. Towards overcoming this limitation, we develop a computational method that optimizes structural performance and information-carrying capacity (ICC) in manufactured parts. We investigate embedding 2D codes into components using a multi-objective optimization framework that combines topology optimization and Bayesian optimization. This approach aims to maximize mechanical performance and ICC, while also enhancing the structural integration of information through adaptive penalization. This adjustment ensures that embedded codes are close to solid regions. Our results show that mechanical performance sensitivity varies with the volume fraction of the topology, with lower fractions exhibiting greater sensitivity. We also present a Pareto frontier to illustrate the trade-offs between ICC and structural performance. The optimally designed parts are fabricated using Fused Deposition Modeling, validating the practicality of our approach.
2:50 PM Cancelled
Improving Binder Jetting Part Strength via a Binder Infill Strategy Guided by Topology Optimization: Amanda Wei1; Joseph Kubalak1; Christopher Williams1; 1Virginia Polytechnic Institute and State University
Traditionally, binder jetting homogeneously deposits binder throughout the entire part cross-section, but recent research has shown that the presence of binder inhibits local densification and that final part density can be significantly improved by reducing the volume of binder saturated powder, or bound powder. However, this reduction occurs at the expense of handleability in the green state; thus, to balance the tradeoff between green part strength and sintered part properties, we apply topology optimization to generatively design non-homogenous binder patterns. The algorithm aims to minimize sintered-state compliance under a bound volume fraction constraint. This incentivizes placement of binder away from the critical load paths to locally improve densification. Parts were optimized, fabricated using 316L stainless steel, and mechanically evaluated in both the green and sintered states. Experimental results suggest that sintered part stiffness can be increased by up to 11.1% with optimized infill patterning.
3:10 PM
Topology Optimised Multi-Material MBB Beam Fabricated via Powder Bed Fusion: Xiaochen Yu1; Jacklyn Griffis2; Jier Wang1; Guhaprasanna Manogharan2; Ajit Panesar1; 1Imperial College London; 2Pennsylvania State University
Multi-material additive manufacturing (MMAM) has recently emerged as a prominent research area due to the significant enhancement in design flexibility. In this work, we adapted a density-based topology optimisation framework called alternating active phase (AAP) algorithm to design a multi-material Messerschmitt-Bolkow-Blohm (MBB) beam. The optimised design was fabricated via multi-material laser powder bed fusion (MM-LPBF), a metal AM process. Both finite element analysis (FEA) and three-point bending tests were conducted to assess the effectiveness of computational optimisation. This research also serves as the early-stage proof of concept in printing multi-material metal structures via MM-LPBF. Preliminary results have shown great potential in balancing competing objectives (i.e. mechanical and thermal), guiding the future work of multi-material design optimisation and fabrication.
3:30 PM
Topology Optimisation of Bespoke Lattice Orthopaedic Implants: Chikwesiri Imediegwu1; Piyapat Jameekornkul1; Peter Ibrahim1; Moataz Attallah1; Ajit Panesar1; 1Imperial College London
Patients who undergo Total Hip Anthroplasty (THA) are known to require revision surgery within ten years. The variance in stiffness between the biocompatible implant material and bone materials often leads to bone remodelling which manifests in pain, aseptic loosening, bone-implant interface fracture and mechanical wear. Metamaterial design and additive manufacturing strategies have expanded the space of achievable mechanical properties. A framework is derived that leverages multiscale topology optimisation and inverse-design to derive optimal implant material layout. This work demonstrates that optimal implant configuration can be derived given patient-specific loading to minimize bone remodelling and the risk for interface fracture and aseptic loosening.