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Heat transfer in the human eyeball, a complex organ, is significantly influenced by various pathophysiological and external parameters. Particularly, heat transfer critically affects fluid behavior within the eye and ocular drug delivery processes. Overcoming the challenges of experimental analysis, this study introduces a comprehensive three‐dimensional mathematical and computational model to simulate the heat transfer in a realistic geometry. Our work includes an extensive sensitivity analysis to address uncertainties and delineate the impact of different variables on heat distribution in ocular tissues. To manage the model's complexity, we employed a very fast model reduction technique with certified sharp error bounds, ensuring computational efficiency without compromising accuracy. Our results demonstrate remarkable consistency with experimental observations and align closely with existing numerical findings in the literature. Crucially, our findings underscore the significant role of blood flow and environmental conditions, particularly in the eye's internal tissues. Clinically, this model offers a promising tool for examining the temperature‐related effects of various therapeutic interventions on the eye. Such insights are invaluable for optimizing treatment strategies in ophthalmology. [ABSTRACT FROM AUTHOR]

Non-toroidal-shaped primary pass-through protection current transformers (CTs) are used to measure high currents. Their design provides them with a big airgap that allow the passing of several cables per phase though them, which is the main advantage versus toroidal types, as the number of CTs required to measure the whole phase current is drastically reduced. The cables passed through the transformer window can be in several positions. As the isolines of the magnetic field generated by the primary currents are centered in the cables, if these cables are not centered in the transformer window, then the magnetic field will be non-uniform along the transformer core. Consequently, local saturations can appear if the cables are not properly disposed, causing the malfunction of the CT. In this paper, the performance of a non-toroidal-shaped protection CT is studied. This research is focused on the influence of the cable position on possible partial saturations of the CT when it is operating near to its accuracy limit. Depending on the cable position, the ratio of the primary and secondary currents can depart from the assigned ratio. The validation of this phenomenon was carried out via finite element analysis (FEA), showing that partial transformer core saturations appear in areas of the magnetic core close to the cable. By applying FEA, the admissible accuracy region for cable positioning inside the CT is also delimited. Finally, the simulation results are ratified with experimental tests performed in non-toroidal protection CTs, varying the primary cables' positions, which are subjected to currents up to 5 kA, achieving satisfactory results. From this analysis, installation recommendations are given. [ABSTRACT FROM AUTHOR]

In order to achieve the optimization objectives of low torque ripple, high torque, and high efficiency, this paper proposes a multi-objective optimization strategy based on genetic algorithms optimizing BP neural network (GA-BP) combined with non-dominated sorting genetic algorithm (NSGA-II) and applies it to the multi-objective optimization design of an external rotor ferrite-assisted synchronous reluctance motor (ERFa-SynRM). Firstly, the preliminary design and selection of ERFa-SynRM structure are carried out. Secondly, a comprehensive sensitivity analysis is presented on the extent to which the design variables affect the optimization objectives. Thirdly, a high-precision prediction model is constructed by GA-BP neural network, and NSGA-II is applied to global optimization of the prediction model. Finally, the electromagnetic performances of the motor before and after the optimization are compared by the finite element analysis (FEA) software. Compared with the initial motor, the average torque and efficiency of the optimized motor are improved, and the torque ripple is reduced by 54.9%, which verifies the effectiveness of the multi-objective optimization design method. [ABSTRACT FROM AUTHOR]

The paper portrays a comprehensive computational procedure for determining the global structural resistances of two existing bridges made of I‐73 and KA‐61 precast post‐tensioned concrete girders using advanced statistical assessment methods in combination with nonlinear fracture mechanics‐based finite element method analysis. Although this combination is a powerful tool for realistic modeling of structures, its practical application is still very time consuming. Therefore, a statistical sampling approach for the determination of the structural design resistance is compared to selected efficient semi‐probabilistic methods based on the estimation of coefficient of variation—estimation of coefficient of variation (ECoV) method according to fib Model Code 2010 and improved approach called Eigen ECoV method. Load‐bearing capacity is determined for the ultimate as well as several serviceability limit states. The sensitivity of the input parameters burdened with uncertainties on the response of the structure is quantified using a sensitivity analysis supported by a surrogate model based on polynomial chaos expansion. The paper shows that the applicability of nonlinear modeling with respect to uncertainties is possible when using these ECoV methods and a surrogate model and can be applied in a routine manner. The shortcomings and advantages of all the used safety design/assessment methods are discussed. [ABSTRACT FROM AUTHOR]

To quantitatively study the coupled dynamic behavior of vehicles in collision with semirigid guardrails, a coupled numerical model is established based on the finite element method. This model comprehensively integrates the nonlinear dynamic behavior of both the vehicle body and the guardrail structure. We validate the numerical results by comparing them with experimental findings and theoretical empirical formulas, confirming the accuracy of the coupled numerical model. This quantitative study investigates the influence of vehicle speed, column wall thickness, and collision angle on this coupled dynamic behavior to help optimize practical guardrail engineering designs. The results indicate that the sensitivity values of the collision speed, column wall thickness, and collision angle according to the baseline model are 1.0, 1.0, and 0.741, respectively. The parameters with higher sensitivity values are the key factors to consider in designs. Thus, the coupled numerical model can be used to optimize the design of semirigid guardrails in practical engineering. [ABSTRACT FROM AUTHOR]

Currently, studies on Xinjiang desert water conveyance channels primarily focus on the selection of construction technologies, with the effects of bank slope reinforcement and the impact of internal and external factors on slope stability remaining unclear. This study utilizes finite element method to analyze the safety coefficient, overall displacement, and equivalent plastic zone of aeolian soil bank slopes before and after reinforcement during three distinct phases: the completion phase, the water transfer phase, and the water level plunge phase. Orthogonal tests were used to assess the trend and weighting of the influence of factors on bank slopes inside and outside the channel using the introduction of corrected range and Spearman correlation analysis. The findings indicate that the safety coefficient for the bank slopes of the desert channel both before and after reinforcement exceeds 1.30 during all phases. Post-reinforcement, the overall displacement and equivalent plastic zone are controlled compared to the pre-reinforced state. Both sensitivity analyses yielded that the factors affecting the weighting of bank slopes were, in descending order, aeolian soil cohesion > slope angle > angle of internal friction > slope height > unit-weight > thickness of concrete lining > height of the water level in the channel > rate of water level plunge; where aeolian soil cohesion, slope angle, angle of internal friction and thickness of concrete lining favoured the stability of the bank slopes, while others were unfavourable to the stability of the bank slopes. This study aims to provide a reference for the construction of desert water supply projects. [ABSTRACT FROM AUTHOR]

This paper proposes a new methodology for sensitivity analysis evaluation, fast and with high precision of the electric potential distribution near the transmission lines (TL's). The TL is modeled by the finite element method and the sensitivity of the cable positions is obtained using the adjoint method. The sensitivity of the objective function during the optimization process by using methods based on gradient information is obtained by using the adjoint method. The exact sensitivity obtained by the adjoint method concerning the numeric model of the TL's results in new geometries of the bundles conductors with high surge impedance loading. These geometries are not possible to get using analytic models. The sensitivities of a large number of conductors by phase are obtained with high precision and very low computational cost using adjoint sensitivities, which are independent of the number of design variables. The central finite difference method is used to calculate the sensitivities and to validate the adjoint method. With this methodology, the FEM model of the TL can be used during the optimization process without compromising the required computational processing time. [ABSTRACT FROM AUTHOR]

The Hybrid Excitation Flux Switching Permanent Magnet (HEFSPM) motor with magnetic bridge is a topology of hybrid excitation Flux-Switching Permanent Magnet (FSPM) machines. Despite its excellent performance such as high torque/power density, high flux enhancing/weakening capability and so on, it has received less attention due to its complicated structure. Therefore, its optimal design and performance all need to be further investigated. This paper presents a multi objective optimization design of a HEFSPM motor with magnetic bridge based on design sensitivity analysis. At first, the machine structure and basic working principle are discussed briefly. Then, a design sensitivity analysis for geometric optimization is carried out to improve the motor performance. This optimized motor is compared with initial design. Finally, a prototype of the optimized proposed motor is built and tested to validate the simulation results. [ABSTRACT FROM AUTHOR]

There are deviations between the radio telescope antenna finite element (FE) model, founded on the design stage, and the actual working antenna structure. The original FE model cannot accurately describe the antenna structure deformation characteristics under the environmental load, thereby compromising the accuracy of the active structural compensation. This article proposes an antenna FE model updating method founded on parameter optimization with a surrogate model. The updating method updates the modulus of elasticity parameters of different components of the antenna backup structure (BUS) to obtain finite element analysis (FEA) results consistent with the actual measurement of the antenna reflector surface shape. The surrogate model founded on the multi-quadratic radial basis function (RBF) improves the computational efficiency of FE model updating, replacing the complex and time-consuming finite element analysis and calculation process. This method is implemented on a radio telescope antenna with an aperture of 25 m. The results show a significant reduction in the mismatch between the antenna and the updated FE model. This method's calculation time is significantly reduced compared with the updating method without using the surrogate model, with the RBF surrogate model taking 1% of the time of the finite element model in the FEA calculations. The proposed method can improve the antenna FE model calculation accuracy and significantly enhance the efficiency of FE model updating calculations. Thus, it can offer a reference for antenna engineering practice. [ABSTRACT FROM AUTHOR]

Summary: A finite element model was established using SAP2000 software for the C1 tower, a super high‐rise building in the second phase of the Nanjing Financial City project, and the construction process of the tower was simulated. The C1 tower adopts a frame core tube extension arm and ring truss structure system, with 87 floors above ground and five floors underground. The roof structure has an elevation of 416.6 m. Precise measurements of inter‐story compression deformation were conducted using advanced surveying equipment. Sensitivity analysis, based on the finite difference method, identified the shear wall elastic modulus, frame column elastic modulus, steel beam elastic modulus, and shear wall unit weight as four highly influential parameters. Employing the Bayesian principle, the Markov Chain Monte Carlo (MCMC) method was applied to determine the posterior density probability function of the parameters targeted for modification. Subsequently, the Metropolis–Hastings (MH) sampling algorithm was employed to refine the C1 Tower model. This refinement significantly reduced the root mean square error between the measured and simulated vertical displacements, achieving an error reduction of approximately 10% from 6.082 to around 2.160. The modified material parameters, for the most part, adhered to a normal distribution assumption and exhibited mean values in the posterior probability density functions for the elastic modulus of Q345 steel beams, C70 frame columns, and C60 shear walls. Compared to the initial finite element parameters, the variation range was approximately 13% to 17%. These results serve as a validation of the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Aero‐disk is a key component of aero‐engine. Due to its complex working conditions, aero‐disk is prone to structural failures. Therefore, it is essential to analyze the reliability and importance input variables of aero‐disk. In this paper, a framework of aero‐disk reliability analysis and global sensitivity analysis (GSA) was established. First, the hazardous regions of aero‐disk were determined by finite element analysis, and the limit state function of aero‐disk was defined by the life interference model. Then D‐Vine model was utilized to establish the correlation model for aero‐disk hazardous regions to evaluate the reliability of aero‐disk. In addition, two GSA methods based on Copula and space partition were proposed to identify important input random variables considering underlying correlation, and the accuracy of the proposed method was verified by two examples. Finally, the proposed method was applied to the GSA of aero‐disk. The results show that the established framework fills in the gap of uncertainty analysis of aero‐disk, which can be extended to other engineering fields. The proposed GSA methods have both high efficiency and accuracy and can realize multi‐dimensional GSA when the correlation of input variables is considered. [ABSTRACT FROM AUTHOR]

An integrated model that considers multiphysics is necessary to accurately analyze the time-dependent response of hydraulic structures on soft foundations. This study develops an integrated superstructure–foundation–backfills model and investigates the time-dependent displacement and stress of a lock head project on a soft foundation during the construction period. Finite element analyses are conducted, incorporating a transient thermal creep model for concrete and an elasto-plastic consolidation model for the soil. The modified Cam-clay model is employed to describe the elasto-plastic behavior of the soil. Subsequently, global sensitivity analyses are conducted to determine the relative importance of the model parameters on the system's response, using Garson's and partial derivative algorithms based on the backpropagation (BP) neural network. The results indicate that the integrated system exhibits pronounced time-dependent displacement and stress, with dangerous values appearing during specific periods. These values are easily neglected, highlighting the importance of integrated time-dependent analysis. Construction activities, particularly the backfilling process, could cause a sudden change in stress and significantly impact the stress redistribution of the superstructure. Additionally, the mechanical properties of concrete have a significant impact on the stress on the superstructure, while the mechanical properties of the soil control the settlement of the integrated system. [ABSTRACT FROM AUTHOR]

Based on the WBS-RBS method, in this study, the risk factors corresponding to the construction risk events of an offshore tunnel foundation pit in Ningbo were identified, and the fuzzy comprehensive evaluation method was used to evaluate the construction safety risk of the project. The system-level risk value was obtained by using the risk event deformation resulting from changes in two factors, namely, "mechanical property of soil" and "stiffness of the envelope structure", to calculate the new event-level risk value corresponding to the deformation using a finite element numerical model. The findings indicate that the tunnel project has a risk evaluation score of 62.78 and thus falls within the category of high-risk projects. A change in risk factors will alter the likelihood that risk events will occur, which affects the safety risk status of the entire project. When two factors are coupled, a project's system-level risk can increase dramatically. [ABSTRACT FROM AUTHOR]

In view of the development trend of rail vehicles towards higher operating speed and low power consumption, a scheme for a lightweight rail vehicle body is proposed, based on sensitivity analysis. Using topology optimization of the vehicle body section structure, finite element models of the vehicle body section structure under single working conditions and multiple working conditions were established, respectively, and the force transmission path of the vehicle body structure under different working conditions was obtained under different working conditions. The topology of the cross-sectional structure of the vehicle body was optimized by the compromise planning method with weights. Then, a reconstruction and performance analysis of the car body section was carried out based on the optimization results and finally the finite difference method was used to analyze the sensitivity of the vehicle body structure and the vehicle body size was optimized based on the sensitivity analysis results. The results showed that the weight reduction rate of the railway vehicle body section stiffened plate was 4.47% compared to the optimization period and the modal performance analysis results of the optimized structure met the requirements. The weight reduction ratio of the optimized body structure was 21.6%. [ABSTRACT FROM AUTHOR]

In this paper the actual dynamic behavior of the civic Clock tower of Rotella, a little village in central Italy heavily damaged by the recent 2016 seismic sequence, is thoroughly investigated by means of a detailed numerical model built and calibrated using the experimental modal properties obtained through Ambient Vibration Tests. The goal is to update the uncertain parameters of two behavioral material models applied to the Finite Element Model (elastic moduli, mass densities, constraints, and boundary conditions) to minimize the discrepancy between experimental and numerical dynamic features. A sensitivity analysis was performed with the definition of a metamodel to reduce the computational strain and try to define the necessary parameters to use for the calibration process. Due to the high nonlinear dependency of the objective function of this optimization problem on the parameters, and the likely possibility to get trapped in local minima, a machine learning approach was meant. A fully automated Finite Element Model updating procedure based on genetic algorithms and global optimization is used, leading to tower uncertain parameters identification. The results allowed to create a reference numerical replica of the structure in its actual health state and to assess its dynamic performances allowing better control over their future evolution. [ABSTRACT FROM AUTHOR]

The paper focuses on the system reliability of steel trusses with correlated variables. The correlation between bearing capacities of bars was considered. Two static truss schemes were considered. Nodal forces were the only load. The Finite Element Method analysis was conducted in Robot Structural Analysis program. To conduct system reliability analysis it is essential to find cut-sets, it was realized by stiffness matrix spectral analysis. Then reliability analysis was performed in Sysrel module of Strurel computing environment. First Order Reliability Method was used as the base, Subset Simulation method was used to check the correctness of the results. The sensitivity analysis of reliability index enabled the authors to draw conclusions, which variables have the greatest influence on the reliability of the structure. The effects of actions and bearing capacities were assumed to be the only random variables and that the excessing the bearing capacities of bars is the only way the structure can get into failure area. [ABSTRACT FROM AUTHOR]

In this work, a parametric study is carried out on carbon fiber-reinforced plastic (CFRP) materials to investigate how the spatially varying fiber distribution influences the measured signal in an eddy current testing (ECT) configuration. The measurement setup was modeled using finite element method, while the fiber distribution is taken into account by an inhomogeneous anisotropic conductivity tensor. The study revealed a trade-off relation between the size of the ECT coil and the maximal dynamic range of the ECT signal, which contributes to the understanding of the connection between the fiber arrangement and the ECT signal and provides an opportunity for optimal ECT coil design. [ABSTRACT FROM AUTHOR]

Introduction: To reliably solve the EEG inverse problem, accurate EEG forward solutions based on a detailed, individual volume conductor model of the head are essential. A crucial--but often neglected--aspect in generating a volume conductor model is the choice of the tissue conductivities, as these may vary from subject to subject. In this study, we investigate the sensitivity of EEG forward and inverse solutions to tissue conductivity uncertainties for sources distributed over the whole cortex surface. Methods: We employ a detailed five-compartment head model distinguishing skin, skull, cerebrospinal fluid, gray matter, and white matter, where we consider uncertainties of skin, skull, gray matter, and white matter conductivities. We use the finite element method (FEM) to calculate EEG forward solutions and goal function scans (GFS) as inverse approach. To be able to generate the large number of EEG forward solutions, we employ generalized polynomial chaos (gPC) expansions. Results: For sources up to a depth of 4 cm, we find the strongest influence on the signal topography of EEG forward solutions for the skull conductivity and a notable effect for the skin conductivity. For even deeper sources, e.g., located deep in the longitudinal fissure, we find an increasing influence of the white matter conductivity. The conductivity variations translate to varying source localizations particularly for quasi-tangential sources on sulcal walls, whereas source localizations of quasi-radial sources on the top of gyri are less affected. We find a strong correlation between skull conductivity and the variation of source localizations and especially the depth of the reconstructed source for quasi-tangential sources. We furthermore find a clear but weaker correlation between depth of the reconstructed source and the skin conductivity. Discussion: Our results clearly show the influence of tissue conductivity uncertainties on EEG source analysis. We find a particularly strong influence of skull and skin conductivity uncertainties. [ABSTRACT FROM AUTHOR]

A probability-based approach, combining deterministic and probabilistic methods, was developed for analyzing building and component failures, which are especially crucial for complex structures like nuclear power plants. This method links finite element and probabilistic software to assess structural integrity under static and dynamic loads. This study uses NEPTUNE software, which is validated, for a deterministic transient analysis and ProFES software for probabilistic models. In a case study, deterministic analyses with varied random variables were transferred to ProFES for probabilistic analyses of piping failure and wall damage. A Monte Carlo Simulation, First-Order Reliability Method, and combined methods were employed for probabilistic analyses under severe transient loading, focusing on a postulated accident at the Ignalina Nuclear Power Plant. The study considered uncertainties in material properties, component geometry, and loads. The results showed the Monte Carlo Simulation method to be conservative for high failure probabilities but less so for low probabilities. The Response Surface/Monte Carlo Simulation method explored the impact load–failure probability relationship. Given the uncertainties in material properties and loads in complex structures, a deterministic analysis alone is insufficient. Probabilistic analysis is imperative for extreme loading events and credible structural safety evaluations. [ABSTRACT FROM AUTHOR]

The complex variable finite element method (ZFEM) is a numerical technique which aims to find the partial derivatives of the independent variables with respect to variation in dependent parameters declared in the physics. This is done by combining the complex Taylor series expansion within the weak formulation of the governing equation in a coupled system of linear equations forming a complex valued block matrix given by the Cauchy–Riemann matrix representation. In this work, two‐dimensional linear first‐order elements have been implemented in ZFEM to predict the design derivatives of the mechanical displacement field and the voltage potential field for a layered piezoelectric system in a steady‐state study with Dirichlet boundary condition applied at the top and bottom edges of the geometry. This approach allows the standard FEM solution to quantify the sensitivity of the mechanical displacement and voltage potential fields with respect to small variations in the material properties through the information obtained from the computation of the derivatives. The domain is formed by a layered body with PZT‐4 and PZT‐5 stacked together. For result verification, the numerical solution obtained with ZFEM was compared to results from a commercial FEM package and the solution from the imaginary part was compared to the exact solution of a well‐known benchmark problem. Comparison of the results showed good agreement for both the real and imaginary parts of the solution and the largest sensitivities were found in PZT‐5 specifically in C13, C33, and ε33. [ABSTRACT FROM AUTHOR]

The aim of this study is to provide an overview of damper sensitivity with dry friction mechanism in relation to its positioning and force to control cable vibrations in cable-stayed bridges. Finite element method is used to implement the cable model. Decay tangent evaluation takes into account the damper position varying in the first 5% of cable total length. To numerically solve the second-order nonlinear ordinary differential equation, the Newmark method with average acceleration is used. The results indicate the appearance of higher vibration modes with the application of dry friction damping, which can influence the interaction between two dampers. With the application of two dry friction dampers to the same cable using the equivalent viscous damping theory and the Newmark method, it is possible to perceive different results, where dry friction presents a considerable gain when not adapted to the linear viscous damping theory. [ABSTRACT FROM AUTHOR]

AbstractIntroducing pulsatility in LVADs is known to reduce complications such as stagnation and thrombosis, but it is an ongoing topic of research on what the optimal form is. We present a framework consisting of parametrized full-order simulations, reduced-order models, and sensitivity analysis to systematically quantify the effects of parametrized pulsatility on washout. As a sample problem, we study the washout in an idealized 2D left ventricle and a parametrized sinusoidal LVAD flow rate. The framework yields speed-ups proportional to the number of samples required in the sensitivity analysis. In our setting, we find that short, intense pulses wash out the left ventricle best, while the time between consecutive pulses does not play a significant role. [ABSTRACT FROM AUTHOR]

In modern times, titanium alloy has a great application prospect in the medical field. Still, the pitiful machinability of titanium alloy material brings incredible difficulty to its ultra-precision cutting. This work presented the effect of parametric sensitivity analysis of the orthogonal cutting process using the finite element method, which dramatically enhances the cutting performance of Ti–6AL–4V. The simulation results are attained by applying Abaqus® explicit 6.14 software. The mechanical reaction of two-dimensional finite element models has been examined for cutting forces. Additionally, the impacts of rake angle, clearance angle, and nose radius on the stress distribution in orthogonal cutting of Ti–6AL–4V have been investigated. Also, to make certain numerical accuracy, the Johnson–Cook constitutive models for Ti6Al4V alloy are implemented. In the end, FE simulation outcomes were supported by the reported results in the literature. [ABSTRACT FROM AUTHOR]

This study investigates the influence of viscous damper parameters on the damping efficiency of frame shear wall structures. Taking a specific frame shear wall structure as the background, a three-dimensional finite element model is established using a nonlinear dynamic time–history analysis method. The damping ratio, reduction in vertex displacement, reduction in base shear, and inter-story drift utilization rate are selected as the damping performance indicators. Firstly, a sensitivity analysis is conducted to study the influence of different viscous damper parameters on these indicators. Then, the relationship models between the viscous damper parameters and the indicators are fitted using the response surface method, and the fitting effect is evaluated through an F-test and determination coefficient R2. Finally, an objective function based on key damping performance indicators is established to solve for the optimal parameters. The results show that the traditional sensitivity analysis method is unable to comprehensively consider the combined effects of different damping efficiency indicators. The response surface method has high fitting accuracy and good predictability and can serve as an optimization model. Considering the stiffness of supporting components matched with the viscous damper parameters, the feasibility of the optimal damping parameters is demonstrated from an engineering application perspective. A simple and easy-to-operate damping design flowchart is proposed, providing important guidance and reference for designers in frame shear wall structure damping design in the future. [ABSTRACT FROM AUTHOR]

To investigate the pipeline deformation pattern caused by the excavation of deep foundation pits in composite soil–rock strata, a comprehensive study integrating on-site monitoring and numerical simulation was conducted. This study centered on a deep foundation excavation project in the soft soil in Nanjing's floodplain region. The analyses of pipeline settlement and deformation were performed based on field-measured data. This study investigated the impact of excavation on the mechanical properties of the surrounding soil that resulted in the progressive deformation of adjacent pipelines. Furthermore, numerical simulations were conducted using Plaxis 3D CONNECT Edition v22 finite element analysis software. This study elucidated the influence of factors such as pipeline–pit distance and burial depth on pipeline deformation, conducting a quantitative analysis of their effects. The results indicated that deformation primarily occurs unevenly near pit corners and is less pronounced in soil–rock strata than in single-type soil layers. This study established correlations between pipeline displacements and various factors, offering valuable insights for future excavation projects conducted under similar conditions. [ABSTRACT FROM AUTHOR]

In ship construction, material costs constitute a substantial portion of the overall expenses. With the surging steel prices, the shipbuilding industry faces a pressing challenge. To counterbalance this issue, optimizing the structural components of ships has emerged as a viable solution. Genetic Algorithm (GA) methods, known for their application in structural optimization, have demonstrated their potential. However, the protracted computational time associated with GA remains a limiting factor. This research introduces a novel approach by merging GA with Finite Element Method (FEM) for optimizing plate sizes, resulting in a hybrid GA system. Moreover, the study incorporates sensitivity analysis (SA) due to its proven efficacy in enhancing optimization processes involving multiple variables. The SA component investigates plate interrelationships and effectively clusters them. After this grouping, the hybrid GA executes parallel optimization of plates that influence each other under tension. By integrating SA, the optimization process becomes faster and more time-efficient, while preserving optimal manufacturing costs. Remarkably, this methodology culminates in a substantial reduction in computational time when contrasted with the hybrid GA approach devoid of SA, all the while maintaining a parallel manufacturing cost trajectory. In conclusion, this study presents an innovative hybrid GA approach, supplemented with SA, as an effective strategy for mitigating the escalating steel costs in shipbuilding. The amalgamation of GA, FEM and SA synergistically simplifies the optimization process, ensuring optimal results in a faster way. [ABSTRACT FROM AUTHOR]

This research dives into the space of "Structural Analysis and Finite Element Methods: Modeling and Reenactment in Mechanical Designing," utilizing a multifaceted approach to comprehensively get the mechanical behaviour of building structures. Finite Element Analysis (FEA) was utilized to scrutinize a steel structure beneath assorted stacking conditions, uncovering stretch conveyances basic for basic optimization. The study amplified its centre to Fluid-Structure Interaction (FSI), unravelling the complex flow between liquid forces and basic reactions, with suggestions for seaward building applications. Warm recreations of composite materials give bits of knowledge into temperature-induced stresses, directing fabric choice and plan alterations in extraordinarily warm situations. Sensitivity investigations and parametric studies methodically investigated plan impacts on auxiliary execution, helping in optimization endeavours. Approval against experimental information guaranteed the precision of numerical recreations, improving their validity. [ABSTRACT FROM AUTHOR]

The significant increase in the speed of high-speed trains has made the optimization of pantograph–catenary parameters aimed at improving current collection quality become one of the key issues that urgently need to be addressed. In this paper, a method and solutions are proposed for optimizing multiple pantograph–catenary parameters, taking into account the speed levels and engineering feasibility, for pantograph–catenary systems that contain dozens of parameters and exhibit strong nonlinear coupling characteristics. Firstly, a surrogate model capable of accurately predicting the standard deviation of contact force based on speed and 14 pantograph–catenary parameters was constructed by using the pantograph–catenary finite element model and feedforward neural network. Secondly, sensitivity analysis and rating of the pantograph–catenary parameters under different speeds were conducted using the variance-based method and the surrogate model. Finally, by combining the sensitivity analysis results and the Selective Crow Search Algorithm, joint optimization of 10 combinations of the pantograph–catenary parameters across the entire speed range was performed, providing efficient pantograph–catenary parameter optimization solutions for various engineering conditions. [ABSTRACT FROM AUTHOR]

For the direct differentiation technique-based modeling of acoustic fluid–structure interaction and structural-acoustic sensitivity analysis, a coupling algorithm based on the finite element method (FEM) and the fast multipole boundary element method (FMBEM) is suggested. By bypassing the challenging volume parameterization process in isogeometric finite element techniques and the laborious meshing process in traditional FEM/BEM, non-uniform rational B-splines (NURBS) isogeometric analysis (IGA) is utilized to immediately perform numerical analysis on CAD models. The matrix-vector products in the boundary element analysis are accelerated using the fast multipole method (FMM). To hasten the solution of the linear system of equations, the iterative solver GMRES is used. The numerical prediction of the effects of arbitrarily shaped vibrating structures on the sound field is made feasible by the FEM/FMBEM technique. A number of numerical examples are provided to show the applicability and effectiveness of the suggested approach. [ABSTRACT FROM AUTHOR]

A computer simulation approach known as the isogeometric (IGA) method may directly use the surface information of geometric model. In 3D computer graphics, Loop subdivision surfaces are a common method for creating complicated shapes. In this study, we propose a coupling algorithm that utilizes Loop subdivision surfaces and a direct differentiation method for the computation of acoustic-fluid-structure interaction and the performance of structural-acoustic sensitivity analysis. This algorithm combines the finite element method (FEM) and wideband fast multipole boundary element method (FMBEM). Because ofthat the proposed method is of a great ability of integrating the numerical calculation and computer-aided modeling, the current technique can deliver results quickly and accurately. The numerical prediction of the effects of vibrating structures with arbitrary shape within sound field is made feasible by the FEM/Wideband FMBEM technique. Calculation examples are provided to show the applicability and effectiveness of the suggested method. [ABSTRACT FROM AUTHOR]

This work focused on the study of efficient solutions for the improvement of the mechanical behavior and movement capability of industrial devices with mobile parts subjected to three-point bending load. To achieve the aim of developing efficient engineering solutions, several stages were followed. A sensitivity analysis was conducted on one of the beams in order to determine the influence of each variable in the mass and in the displacement's parameter space. It has been shown that parameterizing the ANSYS input file is effective for finding out how sensitive the system is to the design variables studied. The results of the sensitivity analysis may be used in the future to choose the variable weights that will be used in optimization techniques and processes. Further study might be performed in the future to attempt to find a way to generalize the methodology for different models and/or in different situations. [ABSTRACT FROM AUTHOR]

The objective of this study was to examine various techniques aimed at improving the mechanical performance and maneuverability of industrial machinery that incorporates movable components under the influence of three-point torsional loads. Multiple measures were implemented to achieve the goal of creating effective technical solutions. A sensitivity analysis was performed on one of the beams to assess the impact of each parameter within the mass and displacement parameter space. Previous studies have shown that the process of parameterizing the ANSYS input file is advantageous in assessing the system's suitability to the design factors being considered. The parameters analyzed were the distance of the inner side plates to the center of mass (VA1), the distance of the inner upper and bottom plates to the center of mass (VA2) and the thickness of all the plates (VA3). The methodology followed was based on the parametrization of an ANSYS input file that was run every time the value of a parameter was changed. This work has potential applications in design optimization procedures, as well as in practical engineering applications, such as laser cutting and engraving machines, and industrial printers, including 3D printers. In future investigations, further research could be undertaken to employ the methodology in diverse circumstances and/or models. [ABSTRACT FROM AUTHOR]

With the increasing importance of vehicle acoustic comfort, the topics of precise absorber simulation and characterization approaches are coming into forefront. The behavior of widely used porous mass-spring systems, consisting of foams coupled with heavy layers, can be strongly influenced by numerous factors. Among them are boundary conditions between trim materials and exciting structures. This paper focuses on investigating trim-structure interface phenomena with the help of modern measurement techniques. Using acquired experimental results, numerical studies have been conducted to account for observed phenomena. In particular, parameter optimization algorithms have been implemented for intrinsic material parameter characterization purposes. Moreover, sensitivity analysis investigations have been performed to substantiate the developed approaches. [ABSTRACT FROM AUTHOR]

The seismic performance of isolated girder bridges is accurately investigated and addressed by considering the theoretical foundation of seismic isolation, taking into account the operational period's service state and changes in relevant performance indicators of vulnerable components. The analysis encompasses a comprehensive parameter analysis of seismic performance during the operational period, utilizing finite element analysis software, which involves comparing and analyzing structural deflections, deformation performance, and damage performance of seismically isolated girder bridges under varying parameters. The research findings indicate that, in terms of evaluating the damage state of the member, the displacement of the girder end of the main girder is primarily influenced by the interface friction coefficient of the isolation device, followed by the post-yield stiffness of the bearing. Conversely, abutment lateral stiffness has a relatively minor influence. Moreover, it is observed that the mechanical properties of the bearing (friction coefficient and post-yield stiffness) exert a significant impact on the structural seismic response. Therefore, more attention should be paid to the functional condition and the variation of mechanical performance parameters of the seismic isolation bearing during the operational phase. [ABSTRACT FROM AUTHOR]

Complex engineering models are typically computationally demanding and defined by a high-dimensional parameter space challenging the comprehensive exploration of parameter effects and design optimization. To overcome this curse of dimensionality and to minimize computational resource requirements, this research demonstrates a user-friendly approach to formulating a reduced-dimension surrogate model that represents a high-dimensional, high-fidelity source model. This approach was developed specifically for a non-expert using commercially available tools. In this approach, the complex physical behavior of the high-fidelity source model is separated into individual, interacting physical behaviors. A separate reduced-dimension surrogate model is created for each behavior and then all are summed to formulate the reduced-dimension surrogate model representing the source model. In addition to a substantial reduction in computational resources and comparable accuracy, this method also provides a characterization of each individual behavior providing additional insight into the source model behavior. The approach encompasses experimental testing, finite element analysis, surrogate modeling, and sensitivity analysis and is demonstrated by formulating a reduced-dimension surrogate model for the damage tolerance of an aluminum plate reinforced with a co-cured bonded E-glass/epoxy composite laminate under four-point bending. It is concluded that this problem is difficult to characterize and breaking the problem into interacting mechanisms leads to improved information on influential parameters and efficient reduced-dimension surrogate modeling. The disbond damage at the interface between the resin and metal proved the most difficult mechanism for reduced-dimension surrogate modeling as it is only engaged in a small subspace of the full parameter space. A binary function was successful in engaging this damage mechanism when applicable based on the values of the most influential parameters. [ABSTRACT FROM AUTHOR]

Full-scale dome structures intrinsically have numerous sources of irreducible aleatoric uncertainties. A large-scale numerical simulation of the dome structure is required to quantify the effects of these sources on the dynamic performance of the structure using the finite element method (FEM). To reduce the heavy computational burden, a surrogate model of a dome structure was constructed to solve this problem. The dynamic global sensitivity of elastic and elastoplastic structures was analyzed in the uncertainty quantification framework using fully quantitative variance- and distribution-based methods through the surrogate model. The model considered the predominant sources of uncertainty that have a significant influence on the performance of the dome structure. The effects of the variables on the structural performance indicators were quantified using the sensitivity index values of the different performance states. Finally, the effects of the sample size and correlation function on the accuracy of the surrogate model as well as the effects of the surrogate accuracy and failure probability on the sensitivity index values are discussed. The results show that surrogate modeling has high computational efficiency and acceptable accuracy in the uncertainty quantification of large-scale structures subjected to earthquakes in comparison to the conventional FEM. [ABSTRACT FROM AUTHOR]

The object of the study was truss-type rod structures, which were investigated for the purpose of finding the optimal design solution in a mixed (continuous and discrete) space of variables. The parameters of the geometric scheme of the truss, as well as the dimensions of the cross-sections of its elements, were considered as design variables. The stated optimization problem is represented as a nonlinear programming task, in which the objective function and nonlinear constraints of the mathematical model are continuously differentiable functions of the design variables. The system of constraints includes strength and stability inequalities, formulated for the design cross-sections of the rod elements of the structure, which is subject to the effect of the design load combinations of the ultimate limit states. As a part of the system of constraints, the displacement constraints formulated for the specified structural nodes, which is subject to the action of design load combinations of the serviceability limit states, are considered. To solve the stated optimization problem, a method of the objective function gradient on the surface of active constraints was used, with the simultaneous elimination of residuals in the violated restrictions. For design variables, the variation of which must be performed according to a given set of possible discrete values, a discretization procedure for the optimal solution obtained in the continuous space of design variables is proposed. A comparison of the proposed optimization methodology with alternative metaheuristic methods and algorithms reported in the literature was performed. On the considered problem of parametric optimization of a 47-span tower structure, a design solution with a weight of 835,403 kg was obtained, which is 1.53...4.6 % better than the optimal solutions obtained by other authors. [ABSTRACT FROM AUTHOR]

This article investigates the influence of porosity and localized edge loads on the vibration and buckling characteristics of functionally graded material (FGM) plates using the finite element (FE) method. The analysis is carried out by choosing a single-layer FGM and two different types of FGM sandwich plates in such a way that there is no material discontinuity along the thickness direction. The porosity imperfections are accounted for in this study as criteria of stiffness reduction and are incorporated using modified power law distribution. The vibration and buckling responses are studied by considering four types of localized edge loads on plates with different porosity distributions. The application of different types of localized edge loads on the plate leads to the development of nonuniform in-plane stresses. Hence, they are computed first by using a dynamic approach before obtaining the buckling loads. The accuracy of the FE formulation is first validated for FGM plates by comparing the natural frequencies and the critical buckling loads obtained in the present investigation with the solutions already available in the literature. After validating the accuracy, detailed parametric studies have been performed on plates with varying volume fraction exponent, porosity distribution, porosity index, side-to-thickness ratio, load width ratio, aspect ratio, and support condition, and the results are presented with appropriate conclusions. A probabilistic sensitivity analysis is carried out to identify the significant parameter affecting the buckling load and natural frequency of porous FGM plates subjected to localized edge loads, which considerably aids in the design of the FGM plates. [ABSTRACT FROM AUTHOR]

Excessive medical waste is generated in various medical facilities, especially post-Covid. Recently, sterilization-based shredding systems are being widely used to treat medical waste; however, such systems are commonly over-designed, due to load variation among various treatment facilities. To overcome this challenge, a data-driven surrogate model framework is proposed to perform sensitivity analysis and design optimization based on different loading environments and capacity requirements. The stress estimation surrogate model was generated using the Latin hypercube sampling (LHS), which can represent the overall information of the design area with a limited sample. Furthermore, the data-driven model significantly reduced the computational time as increased numbers of samples were generated from the data-driven surrogate model, instead of finite element analysis (FEA). Two distinct design capacities of the shredding system were used for assessing the effectiveness of the present framework. The results demonstrated that surrogate model-based sensitivity analysis is an efficient approach to developing system designs based on various input and output conditions. The proposed approach mitigates the tremendous potential of the surrogate model, significantly reduces computational costs associated with sensitivity analysis, and yields promising accuracy for the optimization process. This method suggests a computationally efficient optimization method for different shredding capacities. Additionally, the proposed method does not remain at simply optimizing the existing system but provides optimization values for various capacity systems using the data of the existing design, therefore it can be applied to any mechanical system for designing an optimized and compact system. [ABSTRACT FROM AUTHOR]

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Aiming at the reliability problem of curved steel-concrete composite box girder, this article adopts the research methods of numerical simulation and model test. A load–slip constitutive relationship suitable for simulating composite box girder shear connectors is proposed, which is introduced into ANSYS finite element program and a three-dimensional finite element analysis model is established. At the same time, a model test is established for verification. The comparison between the results of numerical simulation and model experiment verifies the correctness and applicability of the finite element analysis model. According to the mechanical characteristics of the curved steel-concrete composite box girder, the influence of different design parameters on the load-bearing capacity of the curved composite box girder bridge is studied. Based on the sensitivity index, the influence degree of the design parameters on the structural reliability of the curved composite box girder is judged. The influence of the sensitivity of the design parameters of the curved steel-concrete composite box girder bridge on the flexural reliability of the structure is discussed. The optimal measures to improve the flexural bearing capacity of curved steel-concrete composite beam bridges are proposed. It is expected to provide new ideas and analysis methods for the optimization design and reliability analysis of curved composite box girder. [ABSTRACT FROM AUTHOR]

The dynamic loadings can be more harmful than static ones for the human lumbar spine health. Consequently, the prediction of the spine behavior under dynamic and vibration loads is vital and can be achieved by creating a precise finite element model in which the dynamic mechanical properties of the components need to be estimated. For this purpose, noninvasive experimental modal analysis can be applied to evaluate the dynamic mechanical properties of the spine in the numerical simulation by supplying the structural dynamic characteristics (natural frequencies, mode shapes, and damping ratio) of the system. Since the most adequate model for the human lumbar segment is a sheep model, in this paper, a 3D finite element model of a fresh spinal lumber segment of a sheep is generated based on the poroelasticity theory via Abaqus and is updated utilizing particle swarm optimization (PSO) algorithm and experimental modal analysis. In this regard, the frequency response function (FRF) of the specimen is obtained by performing the experimental modal test and the modal parameters are derived by using the rational fraction polynomial method. Afterward, the sensitivity analysis is carried out to determine the appropriate design variables. Finally, the PSO algorithm using experimental data is employed to update the design variables, including the elastic material properties and the structural damping factors of the specimen components, and the stiffness and damping coefficient of the suspension system. According to the results, the error percentage between the numerical FRF and the experimental one decreases remarkably after model updating indicating the high efficiency of the methods used. [ABSTRACT FROM AUTHOR]

To investigate the effect of structural parameters of bridges with unequal spans on the bridge alignment, the finite element model simulating the full-scale bridge was developed, considering the construction process. For ease of finite element modeling and investigation, the section of composite beam with corrugated steel web was first converted into the section composed of the same material. For this purpose, an equivalent method of replacing corrugated steel webs with concrete webs was proposed based on theoretical derivation. After equivalent replacement, the influences of material bulk density, internal prestress, pipe friction coefficient, and pipe deviation coefficient on the main beam at the maximum cantilever stage were analyzed, and the influences of external prestress on the main beam after bridge construction were analyzed. The results show that the most sensitive parameter to structural response is bulk density, subsequently the external prestress, internal prestress, pipe friction coefficient, and pipe deviation coefficient. Among them, the bulk density, internal prestress, and external prestress are all sensitive parameters, while pipe friction coefficient and pipe deviation coefficient are non-sensitive parameters. [ABSTRACT FROM AUTHOR]

One of the effects of creep phenomena in structures is stress relaxation. Owing to this effect, the stiffness of each point is inversely related to the stress at that point, which causes a stress redistribution, a reduction of the maximum stress, and an increment in the displacement field. By contrast, for structural optimization, it is a practical and challenging problem to consider the maximum stress as a failure criterion or objective function. In the present study, the stress relaxation effect was investigated in stress-based topology optimization. The so-called solid isotropic material with penalization method and a nonlinear finite element analysis are utilized for this purpose. The maximum von Mises stress and the total volume of the structure are selected as the objective function and constraint, respectively. The main novelty of this research is to find the optimized topology with the least maximum stress by developing and implementing a time-dependent adjoint method for sensitivity analysis. Implementing the calculated sensitivity for stress-based problems in a gradient-based optimization method, such as the optimality criteria, is quite challenging, and some numerical instabilities in the optimization process are addressed. Several examples are solved with and without considering the stress relaxation effect. The results reveal that the influence of stress relaxation in the reduction of stress concentration makes the optimized layout more similar to the optimized layout obtained by minimizing the compliance for the linear structures. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate the uncertainty of the design variables of a front suspension lower control arm under fatigue-loading circumstances to estimate a reliable and robust product. This study offers a method for systematic uncertainty quantification (UQ), and the following steps were taken to achieve this: First, a finite element model was built to predict the fatigue life of the control arm under bump-loading conditions. Second, a sensitivity scheme, based on one of the global analyses, was developed to identify the model's most and least significant design input variables. Third, physics-based and data-driven uncertainty quantification schemes were employed to quantify the model's input parameter uncertainties via a Monte Carlo simulation. The simulations were conducted using 10,000 samples of material properties and geometrical uncertainty variables, with the coefficients of variation ranging from 1 to 3%. Finally, the confidence interval results show a deviation of about 21.74% from the mean (the baseline). As a result, by applying systematic UQ, a more reliable and robust automobile suspension control arm can be designed during the early stages of design to produce a more efficient and better approximation of fatigue life under uncertain conditions. [ABSTRACT FROM AUTHOR]

The fundamental frequency plays a primary role in the dynamic assessment of Cultural Heritage towers. Local and global features may impact its value: geometric, material features, interaction with the soil and adjacent buildings, aging, the construction phase, and repairs. A database is assembled to study the relationship between the fundamental frequency and the slender masonry structure features. Empirical and physics-based approaches were developed to assess the fundamental frequency from different sources of information. A Rayleigh–Ritz approach is proposed and compared with a 3D finite element model. A sensitivity analysis is then performed to quantify the contribution of each feature. As expected, it is shown that the height of the tower contributes the most to the fundamental frequency. The other tower features have a second-order impact on both the fundamental frequency and the mode shape. A comparison between the different approaches shows that the Rayleigh–Ritz drastically minimizes the difference between numerical and experimental frequencies when all information is available. Empirical relations are a good compromise when less information is available. [ABSTRACT FROM AUTHOR]

To effectively identify the key material parameters of different zones of concrete face rockfill dams and improve the efficiency of parameter optimization, a global sensitivity analysis method of parameters based on sparse polynomial chaotic expansion (sPCE) is proposed in this paper. The latin hypercube sampling method is used to select multiple groups of material parameters, and then finite element method is used to calculate the displacement of dam characteristic nodes in dam body. On this basis, the displacement is expanded by sPCE, and the polynomial basis function is reconstructed by orthogonal matching pursuit to improve the construction and analysis efficiency of the proxy model. According to the chaos coefficients, Sobol' indices are calculated to evaluate the influence of the material parameters and their interaction on different displacements of the dam. The results show that the sPCE model can accurately simulate dam displacement and its statistical characteristics with a relatively small sample size. The sensitivity of the same parameter has spatial variability, and under the influence of parameter levels and spatial distribution of different materials, the parameter sensitivity ranking of different zones has certain differences. The proposed method provides a new reference to sensitivity analysis and uncertainty analysis for practical engineering. [ABSTRACT FROM AUTHOR]

Blast simulators are capable of applying blast-like loading to components in a safe and controlled laboratory environment, overcoming the inherent shortcomings of blast testing in terms of data acquisition, test cycle time, and cost. In this paper, reasonable assumptions and refinements are made to the components and shape of the impact module, a key component of the blast simulator, to achieve diversity in simulated blast loading. By designing four rubber shapes, the importance of ellipsoid rubber as an elastic cushion for simulating blast loading was determined. In order to assess the effectiveness of this optimization, numerical calculations based on a calibrated finite element model were performed around four factors: flat rubber thickness, ellipsoid rubber thickness, impact velocity, and impact modulus mass. Additionally, a grey correlation sensitivity analysis was carried out to evaluate the effect of these factors on the impact loading on the reinforced concrete (RC) slab. The results indicate that peak pressure and impulse had opposite sensitivities to velocity and mass. Changes in ellipsoid rubber thickness had a more positive effect on the impact loading than flat rubber thickness. An in-depth study of the role of these influencing factors is important for the design and improvement of impact modules. [ABSTRACT FROM AUTHOR]

Many optimization problems in electrical engineering consider a large number of design parameters. A sensitivity analysis identifies the design parameters with the strongest influence on the problem of interest. This paper introduces the adjoint variable method as an efficient approach to study sensitivities of nonlinear electroquasistatic problems in time domain. In contrast to the more common direct sensitivity method, the adjoint variable method has a computational cost nearly independent of the number of parameters. The method is applied to study the sensitivity of the field grading material parameters on the performance of a 320 kV cable joint specimen, which is modeled as a finite element nonlinear transient electroquasistatic problem. Special attention is paid to the treatment of quantities of interest, which are evaluated at specific points in time or space. It is shown that the method is a valuable tool to study this strongly nonlinear and highly transient technical example. [ABSTRACT FROM AUTHOR]