Variation Of Design Parameters Research Articles

Experimental and numerical investigations on the bond-slip behavior of the interface between geopolymer concrete and steel tube

This study conducts push-out tests on eight geopolymer concrete filled steel tube column specimens with varying design parameters to evaluate the effects of steel tube wall thickness, concrete strength, and the presence of welded longitudinal ribs on the bond-slip performance at the interface between geopolymer concrete and steel tube. The study analyzes the influence mechanism of chemical bonding force, mechanical bite force, and friction resistance on bond strength and a three-stage bond-slip constitutive relationship is established. The results indicate that steel tube strain increases with height, with significant strain observed at the welding structure and the fixed end of the steel tube. The length-to-diameter ratio, diameter-to-thickness ratio, concrete strength, and construction measures of the steel tube are identified as key factors in enhancing interfacial bonding performance. The presence of welded longitudinal ribs on the inner wall of the steel tube significantly improves the interface bonding. The calculated bond strength ratios, compared with the test results, fall within an 11% margin, demonstrating good agreement.

Post-tensioned coupling beams: Mechanics, cyclic response, and damage evaluation

This study investigates the influence of axial load ratio, initial prestressing ratio, and aspect ratio on the cyclic performance of post-tensioned coupling beams. An analytical solution was derived and verified against experimental studies conducted on post-tensioned beams and a comprehensive numerical parametric analysis was conducted, examining fifty-one scenarios with varying design parameters. These scenarios incorporated three key parameters: the beams’ aspect ratio (span to height), ranging from 1.5 to 3.5; the axial load ratio, ranging from 0.04 to 0.175; and the initial prestressing ratio, ranging from 0.35 to 0.65. Increasing the axial load ratio led to more severe damage, while higher aspect and initial prestressing ratios reduced damage. The axial load ratio had the greatest effect on damage severity, while the aspect ratio mainly influenced the size and length of crushed regions at the beam corners. Deeper post-tensioned coupling beams (aspect ratio <2.5) showed higher coupling shear forces. Increasing the axial load ratio significantly boosted shear capacity, while a higher initial prestressing ratio slightly reduced it. Additionally, both a higher axial load ratio and aspect ratio increased ultimate beam chord rotation, whereas higher initial prestressing ratios decrease it. The estimated stiffness factor, ranging from 0.04 to 0.4, decreased with smaller aspect ratios. Both axial load and initial prestressing ratios had a similar influence on the stiffness factor. A smaller axial load ratio reduced beam-wall interaction and lowered the stiffness ratio, while increasing the initial prestressing ratio raised compressive stress at beam corners, leading to higher initial stiffness and a larger effective moment of inertia. These estimated stiffness factors were then used to derive a relation for the design of post-tensioned coupling beams.

Machine Learning‐Guided Design of 10 nm Junctionless Gate‐All‐Around Metal Oxide Semiconductor Field Effect Transistors for Nanoscaled Digital Circuits

In this paper, we introduce an innovative design approach based on combined numerical simulations and machine learning (ML) analysis to investigate the design key parameters of ultra‐low scale junctionless gate‐all‐around (JLGAA) field‐effect transistor (FET) devices. To this end, precise 3D numerical models that incorporate quantum effects and ballistic transport are employed to simulate the current–voltage (I–V) characteristics of 10 nm‐scale JLGAA FET devices. The influence of design parameter variations and high‐k dielectric material on the subthreshold characteristics is thoroughly examined. Various ML algorithms were employed to analyze and classify the key design parameters influencing the subthreshold figures‐of‐merit (FoMs), the subthreshold swing (SS) factor and ION/IOFF ratio. The obtained results highlight that channel radius and channel doping design parameters are particularly important for affecting swing factor behavior. Similarly, these features also play a significant role in predicting and affecting ION/IOFF current ratio values. Additionally, machine learning is used to determine the optimal design parameters for each figure of merit (FoM) output value. In this context, the models effectively predicted both ION/IOFF current ratios and SS classification, with Naive Bayes achieving an accuracy of 90.8% for ION/IOFF and 92.6% for SS, showcasing the model's robustness in these classification tasks.

Modeling and Comparison of Design Features of Pendulum and Radial Micro-Hydropower Plants Considering the Influence of Variable Design Parameters

This article provides a comparative analysis of pendulum and radial micro-hydropower plants. The novelty of this study lies in the comparative analysis of units that are fundamentally different in design to achieve the most rational option for low-speed rivers. It has been established that a pendulum micro-hydropower plant has a high torque with relatively small dimensions but operates cyclically. At a diameter of 1 m and a blade area of 0.3 m2, the peak torque was 140 N·m. At the same time, the design is sensitive to the blade area and at 0.6 m2 and a lever length of 1.5 m, the torque reached 430 N·m. A radial micro-hydropower plant has lower torque but operates constantly. At an area of 1.23 m2 and a diameter of 1 m, the torque was 40.4 N·m. Accordingly, in terms of specific area with a diameter of 1 m, a pendulum micro-hydropower plant has up to 12 times more torque. It has been established that the pendulum hydropower plant best satisfies the requirements for converting a low river speed into high revolutions of a current generator.

Multistable Composite Laminate Grids as a Design Tool for Soft Reconfigurable Multirotors

Adaptive‐morphology multirotors exhibit superior versatility and task‐specific performance compared to traditional multirotors owing to their functional morphological adaptability. However, a notable challenge lies in the contrasting requirements of locking each morphology for flight controllability and efficiency while permitting low‐energy reconfiguration. A novel design approach is proposed for reconfigurable multirotors utilizing soft multistable composite laminate airframes. These airframes show kinematically determinate morphologies corresponding to multiple minima in their elastic potential energy landscape. By varying design parameters, the methodology allows for tuning the energy landscape characteristics governing each morphology's structural stability and reconfiguration energetics. The airframe, composed of multistable composite laminate grids, is optimized to maximize rigidity under flight loads and minimize reconfiguration work. The 130‐g reconfigurable multirotor design demonstrates self‐locking properties in an open and a folded configuration, enabling a 48% reduction in width‐span without compromising stability during flight. Soft pneumatic actuators, actuated using a tethered compressed air supply, enable reversible reconfiguration on the ground between open and folded configurations. The design resolves the conflicting requirements of high‐stiffness to lock each flight configuration and low‐actuation work for reconfigurability. By exploiting soft yet multistable structures, the approach combines the stability observed in rigid‐linked reconfigurable multirotors with the low‐effort reconfigurability of soft multirotors, offering new methods for designing adaptive‐morphology multirotors.

Novel approaches to assessing brake squeal propensity: comparative evaluation of two index formulations

The persistence of brake squeal as a significant NVH issue within automotive brake systems necessitates the development of robust methods for assessing squeal propensity. This study introduces two novel squeal index formulations for assessment purposes and evaluates their performance against the formulation defined by the SAE J2521 standard. Experimental data essential for formulating the squeal index are collected on a controlled mass-sliding belt experiment. Experiments are performed at three different spring stiffness levels, and squeal index formulations are derived based on time and frequency domain data. The first formulation places particular emphasis on the time domain, explicitly considering the duration of individual squeal events. Conversely, the second formulation is based on the frequency response characteristics of the system, which considers the number of super-harmonic peaks in frequency spectra. To evaluate the performance and discriminatory capabilities of the newly developed squeal index formulations, extensive comparisons are made against the Squeal Index based on the test procedure described in SAE J2521. In conclusion, through meticulous analysis and interpretation of the experimental results, it is discerned that the squeal index formulation defined by time domain exhibits superior efficacy in discerning the nuanced effects of varying design parameters on the occurrence of squeal-like behavior.

Effect of design and surgical parameters variations in mobile-bearing versus fixed-bearing unicompartmental knee arthroplasty: A finite element analysis.

Unicompartmental knee arthroplasty (UKAs) are available in the market as fixed- and mobile-bearing (FB and MB) and can be characterised by a different set of design parameters in terms of geometries, materials and surgical approaches, with overall good clinical outcomes. However, clear biomechanical evidence concerning the consequences of variations of these features on knee biomechanics is still lacking; therefore, the present study aims to perform a sensitivity analysis to see which outcomes are affected by these variations. For both MB-UKA and FB-UKA, five design and surgical parameters were defined (bearing insert thickness, tibial component material, implant components friction coefficient, antero-posterior slope angle and level of tibial bone resection). Two control models were defined based on standard configurations for both implants. Finite element analysis was chosen to perform this study, and different parameter combinations (216 models in total) were implemented and tested at both 0° and 90° of flexion, using a previously validated finite element knee model. The results were then evaluated in terms of bone and polyethylene Von Mises stress and tibio-femoral contact area. Bearing thickness, tibial bone cut and slope angle were found to be the most sensitive parameters for both types of UKAs. Specifically, changes in these parameters in the FB-UKA appeared to induce more significant variations in the polyethylene insert (both in terms of polyethylene stress and contact area), while in the MB-UKA, these changes influenced bone stress distribution more. Surgical parameters returned to have a more significant influence than material and friction variations; furthermore, the outcomes most affected by parameter variations were the insert-related ones for FB-UKA while for the MB-UKA were the ones regarding tibial bone stresses. Not Applicable.

Hardware acceleration of Tiny YOLO deep neural networks for sign language recognition: A comprehensive performance analysis

In this paper, we benchmark two automation frameworks, Vitis AI and FINN, for sign language recognition on a Field Programmable Gate Array (FPGA). We conducted an in-depth exploration of both frameworks using Tiny YOLOv2 networks by varying design parameters such as precision, parallelism ratio, etc. Further, a fair baseline comparison is made based on accuracy, speed, and hardware resources. Experimental findings demonstrate that the Vitis AI outperforms the FINN framework and traditional GPU and CPU platforms by achieving significant improvements of 1.08x, 1.7x, and 2.9x in terms of latency. Leveraging Vitis AI, our system achieved a detection speed of 32.7 frames per second (FPS) on the Kria KV260 FPGA with a power consumption rate of 5.6 W and an impressive mean Average Precision (mAP) score of 61.2% on the Hindi Indian Sign Language (ISL) dataset.

Boosting efficiency in dual-absorber RbPbBr3 perovskite solar cell: the role of two-dimensional GeS and SnS2 as electron transport layers

This paper presents a comprehensive investigation into the electrical characteristics of a perovskite solar cell. The n-i-p cell is based on a low band gap rubidium–lead-bromide (RbPbBr3) perovskite with an energy level of 1.31 eV. The study also evaluates the impact of high mobility two-dimensional GeS and SnS2 as electron transport layers (ETLs) on the cell’s performance. These ETLs have a wide band gap and provide a hole blocking layer due to their high valence band-offset. Additionally, a thin film MoTe2 with a band gap of 1 eV is considered as a complementary absorber for capturing near-infrared solar spectrum. The investigation focuses on the influence of critical physical and structural design parameters on the electrical parameters of the cell. The optimized device with SnS2 as the ETL exhibits a power conversion efficiency (PCE) of 25.03%, an open circuit voltage of 0.95 V, a short circuit current density of 33 mA cm−2, and a fill factor of 80.31%. Similarly, the device with GeS as the ETL achieves a PCE of 25.14%, an open circuit voltage of 0.96 V, a short circuit current density of 33.01 mA cm−2, and a fill factor of 80.66%. Furthermore, a statistical analysis is conducted by calculating the coefficient of variation to assess the sensitivity of the cell’s electrical measures to the variation of design parameters and operating temperature. The results highlight that defects in the absorber layer, work function of the back contact, and ambient temperature are critical design parameters that can significantly impact the device performance. Overall, the utilization of high mobility wide band gap ETLs, in combination with the low band gap perovskite, offers a promising approach for the design of high-performance solar cells.

Mixed-Flow Turbofan Engine Model for the Conceptual Design of Sustainable Supersonic Airplanes

Current research efforts on commercial supersonic flight aim to overcome past challenges by designing a new generation of sustainable supersonic airplanes. Achieving this goal requires careful consideration of the propulsion system during the design process. This study proposes a mixed-flow turbofan engine model coupled with emission estimation routines to increase the reliability of the conceptual design of future supersonic aircraft. The model enables parametric analyses by analyzing variations in main engine design parameters (πc,πf, BPR) as function of the system and mission requirements, such as the Mach number, and suggesting applicability boundaries. The overall methodology was applied to a low-boom Mach 1.5 case study, allowing for both on-design and off-design analyses and generating a propulsive database to support preliminary mission simulations and chemical emission estimation. Finally, the accuracy and reliability of the engine model was validated against GSP 11 data for a generic mixed-flow turbofan engine. A modified version of the Fuel Flow Method, originally developed by Boeing, allowing for emissions estimation throughout the mission for a supersonic engine using biofuels. The application of the methodology led to the definition of an engine with a πc of 30 and BPR of 0.7 for the selected case study, which was successful in meeting the initial mission requirements.

Building and system design's impact on thermal resilience to overheating during heatwaves: An uncertainty and sensitivity analysis

Rising heatwaves necessitate thermally resilient buildings to mitigate occupant heat-stress and mortality, ensuring habitable conditions during thermal shocks. This study's aim and novelty is to identify key design parameters affecting three thermal resilience aspects -(i) shock impact or SET-Dh i.e., degree hours above standard effective temperature threshold of 28 °C (ii) absorptivity time (tabs) and (iii) recovery time (trec) across varying degrees of shock intensities (doS-low, medium and high). A reference Belgian apartment is simulated with varying design parameters (building orientation, envelope and glazing properties, glazing percentage, airtightness, operation and control of passive strategies, cooling systems) during three types of heatwaves. Uncertainty analysis quantified the impact of design variations on thermal resilience, while global sensitivity analysis pinpointed key parameters affecting resilience during different shocks. The study shows that while 87 % of design variations remain thermally resilient during shorter shocks, only 21 % do so during longer shocks and that WWR, cooling capacity, and passive strategies (operation of natural night ventilation and solar shading) have twice the impact on thermal resilience compared to building orientation and glazing properties. While tabs is affected by heat build-up factors (e.g., WWR, solar shading), trec is influenced by heat removal factors (e.g., cooling capacity, NNV). Parameters such as heavy thermal mass extend heat absorption but also delays heat dissipation during prolonged heatwaves. This study guides designers and architects to focus on interventions that enhance buildings' thermal resilience during both short and long heatwaves, aiding in climate adaptation and the ability to withstand future extreme heat periods.

Analytical formulas of coherent-synchrotron-radiation induced microbunching gain and emittance growth in an arbitrary achromatic four-bend chicane

The coherent synchrotron radiations (CSR) emitted by a high-brightness electron beam during transport in a bending magnet is a double-edged sword in electron accelerators. While CSR contributes to a stronger radiation field than the incoherent radiation, it simultaneously leads to degradation of the electron beam quality. Specifically, CSR effects manifest in increases of the beam energy spread and the projected emittance, and amplification of the microbunching instability. A dedicated design of the multi-bend transport lines to mitigate CSR effects has recently become a crucial consideration in modern high-brightness electron accelerators. This paper presents analytical formulas for the CSR-induced microbunching instability gain and for the induced emittance growth in an arbitrary achromatic four-bend chicane with inclusion of both the steady-state and transient CSR effects. For the microbunching instability, an iterative method is employed to solve the integral equation for the bunching factor, providing satisfactory gain formulas. Regarding the CSR-induced emittance growth, based on the linear transfer matrices and incorporating the expressions of the CSR-induced energy spread, analytical formulas are derived for the projected emittance growth in an arbitrary four-bend transport section. The analytical formulas are compared and show good agreement with semi-analytical Vlasov calculations and particle tracking simulations. As an application, the obtained analytical formulas are applied to evaluate the CSR effects in the design of a general achromatic four-bend bunch compressor chicane, providing a quick estimate on the microbunching gain and the induced emittance growth. From the widely adopted symmetric C-shape chicane to a non-symmetric S-shape chicane, a design recently proposed by the co-authors, our analytical formulas offer insight into the evolution of the microbunching gain and the emittance growth with the variations of design parameters. In comparison to the time-consuming, full numerical particle tracking simulations currently employed for CSR effect analyses, the analytical formulas presented in this paper significantly reduce the evaluation time, enabling systematic study of parametric dependencies and comprehensive optimization with inclusion of CSR effects within specified design parameter ranges.

Energy performance tradeoff assessment for varying design parameters in office buildings

ABSTRACT Energy performance and heat release from buildings can differ with variations in envelope and operational parameters. This study presents an evidence-based assessment for different study locations in Japan including Sapporo, Tokyo, and Osaka. The analysis used a comparative approach using a reference energy performance simulation model for large office buildings using EnergyPlus to assess the impact of design variations on building performance. The analysis included 66 simulations with 10 design parameters and 2 construction types. The study coupled energy performance with heat release from the building towards outdoor environments since heat release can influence the local thermal environments. Desirable tradeoffs were observed for timber constructions by increasing the cooling setpoint by 1°C reduced cooling and heating energy use by 10.7% and 11.9% in Sapporo, 8.5% and 22.7% in Tokyo, and 6.8% and 24.4% in Osaka. Similarly, cooling and heating peak loads were reduced by 5.9% and 2.4% in Sapporo, 5.4% and 2.0% in Tokyo, and 6.5% and 5.2% in Osaka. Additionally, nighttime heat release also decreased by 12.4% and 13.6% in Sapporo and Tokyo, and 6.2% and 5.7% in Osaka for concrete and timber constructions. The study provides early-stage design support for energy-efficient buildings and improved local thermal environments.

VALIDATION AND PARAMETRIC STUDY OF LEAN DUPLEX STAINLESS STEEL HOLLOW SECTION STUB COLUMNS BY FINITE ELEMENT ANALYSIS

In this research, a parametric study was conducted on square hollow sections (SHS) and rectangular hollow sections (RHS) columns made of a lean duplex stainless steel (LDSS) grade, namely EN 1.4162. The aim was to determine structural response data due to variations of different design parameters, which is vital in designing structural members. Finite element modeling was utilized for this and the validity of the models was confirmed by comparing them with existing experimental test data. Thickness, corner radius, load eccentricity and slenderness ratio were taken as the varying parameters to study. A total of 32 columns were modeled to study with five variations for each parameter, making a total of 160 variations. For each variation, the ultimate load and the corresponding end shortening were recorded. Each parameter has some effects on ultimate load or end shortening or both except corner radius, which has no significant effect. To visualize the effect of a parameter, a trend line equation was developed by plotting the average result of all column models for each variation of that particular parameter. A linear increase in ultimate load and end shortening can be observed with an increase in column thickness, while opposite trends were witnessed with load eccentricity. Though a linear rise in end shortening was caused by the slenderness ratio, no significant change was seen in the ultimate load of the columns. The mathematical equations presented can be employed to forecast the maximum load-bearing capacity and the associated amount of end shortening when designing structural hollow sections made of LDSS.

Plastic deformation behavior and energy absorption performance of a composite metamaterial based on asymmetric auxetic lattices

This study focuses on the design, behavior and experimental analysis of a novel metamaterial, consisting of an asymmetric auxetic three-dimensional structure (AATS) infused with polyester resin. Utilizing FDM additive printing, samples were created with customizable responses to compressive loads through varied design parameters. The objective is to surpass traditional material blending by enhancing stiffness and energy absorption. Striking a delicate balance, the AATS energy absorption properties are preserved while leveraging the stiffness of the resin. Despite its compact cubic form, not exceeding 27 mm on each side, this metamaterial showcases amplified characteristics, blending the AATS and polyester resin. The results hint at promising applications across military defense, automotive, aerospace sectors, and even potential replacements for articulated human skeletal components.

Influence of design parameters on natural convection heat transfer in additively manufactured body centered cubic lattice structures

The natural convection heat transfer mechanism of the body centered cubic (BCC) lattice structure needs to be clarified for its application in passive cooling thermal management. The BCC lattice heat sinks with various design parameters, such as strut diameter and unit cell length, were fabricated using the laser powder bed fusion process. Subsequently, the thermal performance was experimentally determined for variations in design parameters. The thermal performance tended to be maximized when the relative density of the lattice heat sink constituted approximately 10 %. The numerical analysis was performed to figure out the heat transfer mechanism and investigate the effects of inclination angles. According to numerical results, a lattice heat sink with a smaller strut diameter at the given unit cell length entrains more air than one with a larger strut diameter. However, decreasing strut diameter led to a negative impact on conduction and radiation heat transfer due to the reduction in solid region and surface area. Depending on the inclination angle, thermal performance of a lattice heat sink proportionally decreases. The main cause of performance degradation was the hindrance of plume motion by the base of the heat sink.

Packed Bed Thermal Energy Storage System: Parametric Study

The use of thermal energy storage (TES) contributes to the ongoing process of integrating various types of energy resources in order to achieve cleaner, more flexible, and more sustainable energy use. Numerical modelling of hot storage packed bed storage systems has been conducted in this paper in order to investigate the optimum design of the hot storage system. In this paper, the effect of varying design parameters, including the diameter of the packed bed, the storage material, the void fraction, and the aspect ratio of the packed bed, on storage performance was investigated. COMSOL Multiphysics 5.6 software has been used to design, simulate, and validate an axisymmetric model, which was then applied to evaluate the performance of the storage system based on the total energy stored, the heat transfer efficiency, and the capacity factor. In this paper, a novel-packed bed was proposed based on the parametric analysis. This involved a 0.2 void fraction, 4 mm porous media particle diameter, and Magnesia as the optimum storage material with air as the heat transfer fluid.

Lightweight and broadband metamaterial absorber based on ITO impedance film

In this paper, we present a lightweight, broadband metamaterial absorber that exhibits polarization stability and is insensitive to incident angles. The absorber is composed of one layer of indium tin oxide impedance surface, three layers of quartz fiber composite material, and one layer of paper honeycomb on a metal sheet. Our proposed absorber has a 90 % absorptivity bandwidth of 13.19 GHz, ranging from 4.83 GHz to 18.12 GHz at TEM plane wave normal incidence, covering the entire X and Ku band. We illustrate the variation of design parameters and the distribution of electromagnetic field and current to investigate the absorption mechanism. To demonstrate the effectiveness of our design, we fabricate a prototype sample and measure its absorption performance. The results show a bandwidth of 12.38 GHz, ranging from 4.91 GHz to 17.29 GHz, with a low profile of 0.095λL at the lowest operating frequency. The experimental results are in good agreement with the numerical simulation, effectively verifying our proposed design.

The research on the mechanical properties, microstructure, environmental impacts of environmentally friendly Alkali-activated ultra high performance concrete (AAUHPC) matrix with varied design parameters

Alkali-activated material prepared by the silicon aluminum solid wastes are commonly considered as the low-carbon cementitious material, which has important significance for promoting the sustainable development of construction materials. The mechanical properties, reaction mechanisms, and microstructure evolutions of Alkali-activated Ultra High Performance Concrete (AAUHPC) matrix with 7 design parameters were comprehensively studied through testing the fluidity, 28 days compressive strength, 28 days flexural strength, hydration heat, and microstructures. The environmental impacts including carbon emissions and energy consumption are evaluated. Appropriately increasing Na2O dosage, silicate modulus (Ms), and granulated blast furnace slag (GBFS) to fly ash (FA) mass ratio (GBFS/FA) and decreasing silica fume (SF) content and water to binder ratio (W/B) are conducive to accelerating the early reaction of AAUHPC. High Na2O dosage, Ms, SF content, and W/B are not conducive to increasing the 3 days reaction degree of AAUHPC, while the moderate GBFS/FA is corresponding to the higher 3 days reaction degree of AAUHPC. The optimal Na2O dosage, Ms, GBFS/FA, SF content, sand to binder ratio (S/B), fine sands content in quartz sands, W/B are 8 %, 1.4, 4.5:1, 10 %, 1.0, 50 %, and 0.34 for the 28 days mechanical properties. The acquired AAUHPC matrix with fluidity of 218 mm and the lowest porosity has 28 days compressive strength of 114.8 MPa and 28 days flexural strength of 10.6 MPa, whose microstructure has more high polymerization degree C(N)-A-S-H gels with higher Al/Si, lower Na/Al, and lower Ca/Si molar ratios. Compared to the traditional Ultra High Performance Concrete (UHPC), the environmentally friendly AAUHPC can reduce the carbon emission by 42%–52 % and the energy consumption by 5%–18 %. The total CO2 emission of per unit compressive strength (1.0 MPa) of concrete per cubic meter (CI) is in range of 2.5–3.7 kg, which is significantly lower than the traditional UHPC (6.98 kg/MPa•m3).

Multi-Objective Optimization for Complex Systems Considering Both Performance Optimality and Robustness

As engineering systems become increasingly complex, performance requirements rise, and tolerance for design parameter variations becomes more crucial due to increased uncertainty. Tolerance to parameter variation can be measured by the volume of the solution space. A larger solution space implies a higher tolerance to parameter changes and thus greater robustness. The box-shaped solution space, represented by intervals with respect to each design parameter, has the advantage of showing which design parameters can be decoupled. Therefore, this paper proposes a new multi-objective optimization problem to optimize both the performance and volume of the box-shaped solution space simultaneously. Often, optimal performance and maximum volume are conflicting objectives, indicating a trade-off between performance and robustness. Furthermore, the DIRECT-NSGA-II approach is proposed for solving this multi-objective optimization problem. The DIRECT algorithm evaluates the minimum value of the performance function within the box-shaped solution space, while the NSGA-II algorithm identifies Pareto-optimal solution spaces. Finally, two case studies are implemented to illustrate the effectiveness of the DIRECT-NSGA-II method. We can conclude that (I) the proposed DIRECT-NSGA-II approach is suitable for black-box performance functions, (II) any point within the obtained solution space is a good design point, and (III) the proposed optimization problem considers both performance optimality and robustness, enabling the identification of a representative set of Pareto-optimal solution spaces that balance these two factors.