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The effective design of metallic metamaterials, characterized by interconnected struts or 'lattices,' hinges on the ability to predict strut and strut intersection ('node') responses. This is critical for predicting the macroscopic properties of structures comprised of thousands of struts. Computationally efficient beam descriptions, defined by strut properties like cross-sectional area, modulus, and yield stress, can significantly expedite the prediction of lattice structures and ultimately enable topology optimization. This paper provides a comprehensive examination of the properties of electron-beam melted three-dimensional printed struts and their 'nodes'—four intersecting struts. The findings elucidate the efficacy of various strategies for defining effective properties that accurately capture mechanical response. The study reveals that using a single set of effective properties can introduce inconsistencies between strut stiffness, peak load, and critical displacement. Stiffness correlates with averaged cross-sectional areas, while the peak load capacity correlates more closely with minimum inscribed cross-sectional areas. Analysis of nodes indicates that the interaction of surface defects and heterogeneity within the node strongly influences multi-strut response. Data from CT scans, EBSD scans, and nanoindentation maps highlight spatial variations comparable to the strut diameter, posing a significant challenge in defining effective homogenized properties. This study emphasizes the need for future efforts to integrate statistical property distributions with high throughput simulations to overcome the difficulty in defining a representative volume element (RVE) at the strut scale.

The winning game outcome in basketball is partially contingent on the team's ability to secure and make more free-throw shooting attempts, especially close to the end of the game. Thus, the purpose of the present study was to perform a comprehensive biomechanical analysis of the free-throw shooting motion to examine differences between (a) proficient (≥70%) and non-proficient shooters (

Three-dimensional force plates are important tools for biomechanics discovery and sports performance practice. However, currently, available 3D force plates lack portability and are often cost-prohibitive. To address this, a recently discovered 3D force sensor technology was used in the fabrication of a prototype force plate. Thirteen participants performed bodyweight and weighted lunges and squats on the prototype force plate and a standard 3D force plate positioned in series to compare forces measured by both force plates and validate the technology. For the lunges, there was excellent agreement between the experimental force plate and the standard force plate in the X-, Y-, and Z-axes (r = 0.950–0.999, p < 0.001). For the squats, there was excellent agreement between the force plates in the Z-axis (r = 0.996, p < 0.001). Across axes and movements, root mean square error (RMSE) ranged from 1.17% to 5.36% between force plates. Although the current prototype force plate is limited in sampling rate, the low RMSEs and extremely high agreement in peak forces provide confidence the novel force sensors have utility in constructing cost-effective and versatile use-case 3D force plates.

This study examined the effects of cycling training on mechanomyographic median power frequency (MMGMDF)–torque relationships of the vastus lateralis (VL). Ten males (Age ± SD; 20.20 ± 1.87 years) and 14 females (21.93 ± 5.33 years) performed isometric trapezoidal muscle actions with the knee extensors at 40% maximal voluntary contraction (MVC) before (PRE) and following 10 weeks of cycling training at the same absolute submaximal torque as pre-training (POSTABS). MMGMDF–torque relationships (increasing and decreasing segment) were log-transformed and b terms (slopes) were calculated. MMGMDF was averaged during steady torque. For POSTABS, the b terms for the females (0.133 ± 0.190) were greater than for the males (−0.083 ± 0.200; p = 0.013) and compared to PRE (0.008 ± 0.161; p = 0.036). At PRE, the b terms for the linearly increasing-muscle action (0.123 ± 0.192) were greater compared to the linearly decreasing-muscle action (−0.061 ± 0.188; p < 0.001), whereas no differences existed between muscle actions for POSTABS (p > 0.05). In conclusion, 10 weeks of cycling training resulted in different motor unit (MU) control strategies between sexes and altered MU control strategies between muscle actions for the VL during a moderate-intensity contraction.

We develop a strategy to design and evaluate high-entropy alloys (HEAs) for structural use in the transportation and energy industries. We give HEA goal properties for low (≤150 °C), medium (≤450 °C) and high (≥1,100 °C) use temperatures. A systematic design approach uses palettes of elements chosen to meet target properties of each HEA family and gives methods to build HEAs from these palettes. We show that intermetallic phases are consistent with HEA definitions, and the strategy developed here includes both single-phase, solid solution HEAs and HEAs with intentional addition of a 2nd phase for particulate hardening. A thermodynamic estimate of the effectiveness of configurational entropy to suppress or delay compound formation is given. A 3-stage approach is given to systematically screen and evaluate a vast number of HEAs by integrating high-throughput computations and experiments. CALPHAD methods are used to predict phase equilibria, and high-throughput experiments on materials libraries with controlled composition and microstructure gradients are suggested. Much of this evaluation can be done now, but key components (materials libraries with microstructure gradients and high-throughput tensile testing) are currently missing. Suggestions for future HEA efforts are given.

Microstructure and phase composition of a CrMo0.5NbTa0.5TiZr high entropy alloy were studied in the as-solidified and heat treated conditions. In the as-solidified condition, the alloy consisted of two disordered BCC phases and an ordered cubic Laves phase. The BCC1 phase solidified in the form of dendrites enriched with Mo, Ta and Nb, and its volume fraction was 42%. The BCC2 and Laves phases solidified by the eutectic-type reaction, and their volume fractions were 27% and 31%, respectively. The BCC2 phase was enriched with Ti and Zr and the Laves phase was heavily enriched with Cr. After hot isostatic pressing at 1450 °C for 3 h, the BCC1 dendrites coagulated into round-shaped particles and their volume fraction increased to 67%. The volume fractions of the BCC2 and Laves phases decreased to 16% and 17%, respectively. After subsequent annealing at 1000 °C for 100 h, submicron-sized Laves particles precipitated inside the BCC1 phase, and the alloy consisted of 52% BCC1, 16% BCC2 and 32% Laves phases. Solidification and phase equilibrium simulations were conducted for the CrMo0.5NbTa0.5TiZr alloy using a thermodynamic database developed by CompuTherm LLC. Some discrepancies were found between the calculated and experimental results and the reasons for these discrepancies were discussed.