Conference Agenda

In the development of ventricular assist devices (VADs), torque stability in electric motors is critical to ensuring continuous blood flow and minimizing adverse hemodynamic effects. This research describes a multi-objective geometric optimization framework for minimizing ripple torque in a brushless DC (BLDC) motor designed for a VAD with an axial drive but no central shaft. The electromagnetic model was implemented using the finite element method in COMSOL Multiphysics and coupled to MATLAB via LiveLink™, allowing for the automatic evaluation of geometric configurations. Five rotor and stator design parameters were designated as choice variables, and an optimization problem was established with three objectives: limiting torque variation, maintaining a minimal average torque of 50 mN·m, and regulating the air gap area. Optimization was performed using the NSGA-II evolutionary algorithm, running approximately 5000 model evaluations. The results showed that it is possible to reduce ripple torque from 14.8% in the original configuration to values below 5% within the Pareto feasible set, while maintaining the minimum axial torque requirement. The analysis revealed an inherent trade-off between ripple reduction and average torque magnitude. The proposed methodology proves to be an effective tool for the electromagnetic optimization of BLDC motors in biomedical applications.

This study presents the structural design and analysis of a chassis for a compact electric vehicle using the Finite Element Method (FEM). The chassis was modeled in Autodesk Inventor and evaluated through static simulations in ANSYS under four scenarios: full load with all wheels on the ground, asymmetric loading with one front wheel suspended, one rear wheel suspended, and emergency braking. Results show that under full load, the maximum displacement was 0.575 mm, indicating high stiffness. The most critical deformation occurred with a suspended front wheel, reaching 3.234 mm, while emergency braking generated the peak stress of 136.04 MPa, remaining well below the yield strength of structural steel. These findings confirm that even under extreme conditions, the chassis operates within the elastic range. Material comparison revealed distinct behaviors. Structural steel and Q345 exhibited similar stiffness and strength, limiting displacement to 3.234 mm under torsional load and maintaining stresses of 136 MPa during braking. Aluminum, in contrast, offered significant weight reduction but showed greater flexibility, with displacements up to 9.841 mm and stresses limited to 44.7 MPa, suggesting its viability only with geometric reinforcement. Overall, the proposed chassis design meets safety and performance requirements across all scenarios. The study also identifies improvement opportunities through localized reinforcement and geometric optimization—such as increasing thickness in high-stress regions or replacing rectangular profiles with circular sections without significantly increasing weight. These results provide a foundation for future optimization and dynamic analysis, supporting the development of lightweight, efficient, and structurally robust electric vehicle platforms.

Brake pad selection impacts safety, stopping performance, and thermal behavior, especially when vehicle mass and usage conditions vary. This paper presents a controlled road-test comparison of three disc brake pad categories—Original Equipment Manufacturer (OEM), Original Equipment (OE), and Independent Aftermarket (IAM)—installed on the same light sport utility vehicle and evaluated under two load states (unloaded and loaded). Each configuration was tested with five repeated full stops from a nominal initial speed of 90 km/h on dry asphalt, capturing stopping time and distance, peak brake-pad temperatures (front/rear), and peak hydraulic line pressures (front/rear). Results are reported as mean ± standard deviation and complemented with variability metrics. Across all tests, loading increased stopping distance and time, and relative performance depended on pad category. Under unloaded conditions, the OEM configuration achieved the shortest mean stopping distance (25.03 m) and time (2.00 s), while OE and IAM exhibited longer stops. Under loaded conditions, OEM and OE were comparable in distance and time, whereas IAM showed a larger degradation. The dataset supports a repeatable, instrumentation-driven workflow for pad benchmarking and highlights the importance of reporting dispersion—not only averages—when assessing braking components.

The design of spark-ignition (SI) engines for renewable and alternative fuels demands strategies that overcome knock constraints and the limited exergetic efficiency of conventional Otto-cycle operation. This research proposes a theoretical framework grounded in a thermodynamic principle that formalizes exergy in Otto cycles by integrating efficiency, entropy generation, fuel physicochemical properties, and combustion conditions as coupled design variables. The work consolidates more than a decade of theoretical and experimental studies, culminating in an integral exergetic balance equation that captures the dynamic evolution of exergetic efficiency across the cycle and yields a general principle applicable to real engines.
The framework provides a rational basis for selecting high compression ratios, lean operation, and EGR-based dilution to enable stable operation near the knock threshold while preserving efficiency. Simulation results and experimental validations using biogas, methane, hydrogen, and representative blends are presented, showing measurable gains in thermal and exergetic performance relative to traditional configurations. Finally, the proposed “Fifth Law of Thermodynamics for engines” is introduced as a unifying foundation that links efficiency, irreversibilities, and fuel-adapted design, offering a new scientific pathway for high-efficiency, sustainable engine development—particularly relevant to Latin America.
“True efficiency does not lie in the most energetic fuel or the fastest combustion, but in designing the system around the fuel that best resists knock; only then can exergy be maximized and the traditional limits of the Otto cycle be surpassed.”

This work presents the design and preliminary validation of a passive mechanical aid intended to assist arm elevation during naval welding tasks. Shipyard operations require sustained overhead postures, which increase the risk of developing musculoskeletal disorders (MSDs). The methodology included ergonomic analysis, biomechanical characterization using surface electromyography (sEMG), and engineering design tools. A concept based on a compression spring was selected and developed through CAD modeling, Denavit–Hartenberg kinematics, and finite element analysis (FEA). A TRL-3 level prototype was obtained, validating the structural feasibility of 3D-printed materials (PLA-CF and PC-PTFE). Initial tests confirm the preservation of mobility and structural strength of the design.

Mass moment of inertia (MMI) is critical in the study of motion of rigid bodies in dynamics. However, its precise determination can be challenging when dealing with complex shapes such as vehicles, airplanes, trains, and human bodies.

To determine the moment of inertia, several analytical studies have been conducted and many experimental methods applied. Those experimental methods, however, require a substantial amount of work, materials, and time, resulting in high cost and danger. Therefore, the need for simple and accurate mathematical models, confirming the results of experimental methods, is warranted.

The main objective of this paper is to formulate a general equation of MMI to be validated and corrected using the experimental data from Matsuo [7] and Tozeren [9]. The outcome of the application of the obtained general equation to an African university student population and to a larger set of US college students’ sample is also investigated.