2026 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2026): Lattice Design, Computational Optimization, and Mechanical Behavior
Program Organizers: David Leigh, University of Texas at Austin
Tuesday 8:00 AM
August 4, 2026
Room: Comal
Location: AT&T Center
8:00 AM
One-To-Many Inverse Design of Curvy Strut-Based Lattices Using Mixture Density Networks: Xiaochen Yu1; Ajit Panesar1; 1Imperial College London
Lattice structures are architected materials that enable functional grading through tailored unit cell design. This works proposes a machine learning (ML)-based inverse design framework that maps target properties to multiple admissible design candidates, addressing the inherent “one-to-many” nature of the inverse problem. The framework is built on a novel parameterisation of a curvilinear body-centred cubic (curvy-BCC) unit cell, where non-uniqueness arises from variations in strut orientation and thickness. The design space is further expanded by incorporating multiple materials and unit cell topologies. The framework integrates a material classifier, a topology classifier, mixture-density-network (MDN)-based inverse generators, and a property predictor to generate multiple valid design candidates all with high property satisfaction, enabling further selection based on performance or manufacturability criteria. Moreover, probability measures derived from MDNs offer insights into solution reliability and diversity, as well as the feasibility of the target properties, bridging the gap in existing data-driven inverse design methods.
8:20 AM
Nonlinear Graded Lattice Optimisation for Orthotropic Materials: Aya Hosoi1; Ajit Panesar2; 1Imperial College London, Asahi Kasei Corporation; 2Imperial College London
Lattice structure, a quasi-repetition of unit cells (UCs), is multi-scale in nature and its effective property is tailorable by tuning the UCs’ geometries. This study advances on the authors’ former numerical graded lattice design approach to consider practical application by incorporating geometrical nonlinearity and orthotropic material properties. The designed lattice structures were fabricated using additive manufacturing and validated through three-point bending test, where the superiority of the optimal structures over their uniform counterparts were confirmed. Beneficial effect of fibre reinforcement was also obtained, based on the better performance of the orthotropic material-based lattice structures compared to the isotropic material. Preliminary results on nonlinear lattices exhibited asymmetric optimal topology, incorporating the effect of rigid body rotation of the design domain due to the large deformation. This study aims to integrate realistic application scenarios to the validated methodology to accelerate the application of numerical design of graded lattices.
8:40 AM
Multi-Objective Design Optimization of Auxetic Based Solid-Lattice Hybrid Structures for Additive Manufacturing: Sri Bharani Ghantasala1; Gurminder Singh1; 1Indian Institute of Technology Bombay
This study presents auxetic-based solid-lattice hybrid structures for lightweight components with high energy-absorption capabilities. A hexagonal auxetic structure and six modified variants were evaluated by varying key geometric parameters, including member length (5 - 9 mm), orientation angle (50 - 70 °), and extrusion thickness (0.4 - 0.8 mm), using a design of experiments approach. The Johnson-Cook plasticity model was adopted to predict the effective modulus, strain energy absorption and stress distribution over the lattice structure under prescribed loading conditions. A Gaussian process regression model combined with NSGA-II enabled multi-objective optimization to minimize mass while maximizing stiffness and energy absorption. The optimal design, with parametric values of length: 5.012 mm, angle: 60.25 °, and thickness: 0.4002 mm, resulted in a ~43% weight reduction and enhanced energy absorption. Finally, the optimized auxetic lattice was integrated into a topologically optimized structure forming a solid-lattice hybrid design for additive manufacturing.
9:00 AM
Towards Field Driven Design of Cellular Materials for Energy Absorption: Modeling and Simulation of Variable-Thickness Schwarz-P TPMS Structures: Mandar Shinde1; Irving Ramirez-Chavez1; Dhruv Bhate1; 1Arizona State University
The design, modeling and optimization of cellular materials for energy absorption remains one of the more challenging sub-domains within architected cellular and meta-materials for mechanical behavior. The work in this field is primarily of an empirical and experimental nature with most of it involving constant thickness cellular structures. This gap can be attributed to the modeling challenges associated with accurately representing the large deformations and contact seen in cellular materials subjected to very large compressive strains. This work addresses this gap by proposing, developing, implementing and validating a continuum shell based finite element model that enables the simulation of the behavior of variable thickness Schwarz-P TPMS cellular structures. Four different fields: two rational (linear gradient and failure band) and two stochastic, are implemented and studied, with all showing improvements over the uniform thickness baseline.
9:20 AM
Aperiodicity in Cellular Materials and the Missing Link: A Multiscale Statistical Analysis of Mechanical Behavior Using Meso-structural Quantification and Digital Image Correlation: Irving Ramirez-Chavez1; Daniel Anderson1; Nicole Van Handel1; Tyler Hayes1; Shawn Clonts1; Swapnil Morankar2; Nikhilesh Chawla2; Dhruv Bhate1; 1Arizona State University; 2Purdue University
While much is known about how aperiodicity influences the mechanical behavior of cellular materials, this work seeks to answer why it does so. It proposes a new, multiscale approach, arguing that there is a “missing link” between relating local deformation in cellular materials and their global response – and further, proposes quantification of the meso-structure as the central analysis that needs to be conducted to close this gap. Honeycombs with increasing levels of perturbation are used to demonstrate this, finding hitherto unreported correlations between effective elastic moduli and the standard deviation of the strain component along the loading direction, which itself depends on the standard deviation of the normalized beam length. This study hints at the potential for uncovering new insights by leveraging a multiscale approach that combines global stress-strain response, mesostructural quantification and local point-wise strain information into an integrated statistical analysis.
9:40 AM Break
10:00 AM
Topology-Dependent Mechanical Response of Gyroid and Triangular Lattice Infill in Metal Additive Manufacturing: Zarin Tahsin1; Aref Yadollahi1; Seyedmostafa Nasrollahpourshirvani1; Oscar Queralt Torrecillas1; Rauan Yeralkhan1; Matthew John Prescott1; Mohammad Mahtabi2; 1Purdue University Northwest; 2The University of Tennessee at Chattanooga
Architected lattice infill in metal additive manufacturing (AM) enables mass reduction and property tailoring, yet the structural integrity of these topologies relative to solid counterparts under diverse loading conditions remains insufficiently quantified. This study evaluates gyroid, a triply periodic minimal surface (TPMS), and triangular strut-based lattice architectures in 17-4 PH stainless steel fabricated via atomic diffusion additive manufacturing, considering both as-built and H900 heat-treated conditions. A comprehensive experimental framework integrating tensile, compression, and Charpy impact testing with microstructural characterization and fractography is employed to establish topology-dependent mechanical response. The performance of lattice architectures is compared with their solid counterparts, and load-bearing capacity is evaluated with respect to effective material volume to enable consistent comparison across configurations. The results quantify the influence of lattice topology and post-processing on strength, deformation behavior, and energy absorption, providing a basis for assessing performance–manufacturability tradeoffs in lightweight metal AM components.
10:20 AM
Ultra-Compliant High-Density Bundle Structures: Formalization, Computational Design, Additive Manufacturing and Mechanical Behavior: Zack Okun1; Ava Jazwin1; Dhruv Bhate1; 1Arizona State University
Fiber bundles in both natural and engineered systems demonstrate impressive mechanical properties. However, little has been done to abstract their underlying design principles for additive manufacturing. To address this gap, this research developed a parametric design platform capable of generating a variety of 3D fiber bundle models. This platform enables modeling of key structural parameters in fiber bundles, including the number and configuration of fiber strands, strand heights, the degree of strand twist, and fiber hierarchy. To assess the mechanical benefits of these designs, the designs were manufactured using Selective Laser Sintering and subjected to four different loading conditions: tension, compression, bending and torsion. Results indicate a significant increase in compliance with increasing twist angle for bundle structures even while preserving mass, showing promise for space-filling 3D bundles that enable ultra-compliance at high relative densities, which may have applicability in piezoelectric sensing, as well as in energy harvesting and absorption.