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Surface cracks typically exhibit a range of characteristics, including varying depths and inclined angles. Investigating the interaction between ultrasonic surface waves and these cracks is crucial for the non-destructive evaluation of their properties. In this work, the amplitudes of Rayleigh waves scattered in the far field by inclined surface open cracks with depths exceeding the wavelength are

As new infrastructures for the "first mile" in an agricultural supply chain, origin warehouses are highly valued and supported for reducing the loss of agricultural products. With this regard, we develop a bi-level programming model for optimizing the construction and operation of agricultural product origin warehouses. Specifically, the upper-level supply chain enterprise makes decisions regarding

In this paper, a 3D steady-state general solution for isotropic thermo-chemo-elastic media with multi-species diffusion is derived by introducing two displacement functions and utilizing the rigorous operator theory together with generalized Almansi's theorem. Based on the derived general solution, fundamental solutions for the problems of intact half-infinite, infinite, and bi-material bodies subjected

This study introduces physics-informed neural fractional differential equations, a novel approach that integrates neural ODE, fractional calculus, and physics-informed machine learning to advance the modeling of dynamical systems. Traditional methods often struggle to capture intricate systems' long-range dependencies and memory effects. Physics-informed neural fractional differential equations address

Effectively addressing nonlinear small-sample data has been a critical focus in time-series research. Due to their “black-box” nature and strong reliance on data scale, traditional machine learning models often struggle with such datasets, prompting many studies to adopt neural grey models. However, existing neural grey models frequently suffer from overfitting and limited predictive accuracy. To address

Modeling the motion and interactions of particles with complex shapes in two-phase flow systems presents significant challenges. In this study, we aim to develop an efficient and stable hydrodynamic model for simulating two-phase flow systems involving particles with generalised cross-sectional shapes. Firstly, a geometric representation model (GRM) is developed to precisely characterize arbitrary

As critical supporting components in rotor systems, angular contact ball bearings play a pivotal role in maintaining operational stability. In high-speed applications, the structural parameters and loading conditions of these bearings significantly influence the ball-cage interactions, consequently affecting the dynamic performance of the cage. To systematically investigate the dynamic interaction

Electrohydrodynamic (EHD) cone-jet is a widely studied research topic owing to its variable outcomes and broad applications in micro/nanoscopic additive manufacturing. Among all the EHD cone-jet outcomes, the varicose and whipping instabilities attract much attention because of their rich underlying physics involved in the unstable downward stretching jet. However, the mechanisms behind these two instabilities

This study investigates the interaction between turbulent conductive jets and transverse magnetic fields, focusing on the effects of jet inclination angle and magnetic field strength. This phenomenon is relevant to both metallurgy and astrophysics. In metallurgy, complex localized magnetic fields are frequently used to control molten metal flows. Similarly, in astrophysics, a comparable effect occurs

Natural disasters, such as floods and fires, affect various regions of the world every year. One of the most critical aspects of disaster management and planning is facilitating the evacuation of people. Therefore, this study develops a mathematical model for emergency evacuation, taking into account the constraints and limitations of transferring individuals to shelters. The model, called the maximal

In this paper, we investigate the flux identification problem for a nonlinear time-fractional viscoelastic equation with a general source function, using boundary measurements. We first establish the well-posedness of the direct problem by proving the existence, uniqueness, and continuous dependence of the solution on the heat flux. Next, we demonstrate the Fréchet differentiability of the cost functional

Considering gliding waverider vehicle is often subjected to mismatched and matched disturbances, designing a strongly robust controller to accurately limit transient performance and ensure high-precision convergence of tracking error is of great significance for flight safety. Therefore, this paper investigates an adaptive mollified prescribed performance controller for waverider vehicle, including

This paper analyzes the nonlinear static and dynamic buckling responses of graphene platelet (GPL) reinforced shallow spherical caps and circular plates with porous core and stepped spiderweb stiffeners. The new design of stepped spiderweb stiffeners is proposed by adding meridian stiffeners near the edge region, and three regions are created as the edge region, the middle region, and the top region

Maintaining tunnel face stability during underwater shield tunneling through longitudinally heterogeneous strata remains a critical challenge, with limited theoretical research addressing this issue. This study presents an improved limit equilibrium model to assess tunnel face stability, specifically considering the failure zones on both sides of the interface. The model's validity is demonstrated

In this study, an asymptotic analysis of plane strain deformation and associated stress fields in the vicinity of a steady moving crack tip in a class of compressible hyperelastic materials is formulated. It is assumed that the semi-infinite crack is in a homogeneous Ciarlet-Geymonat material under general mixed mode I/II loads. The crack tip deformation, stress and the Jacobian determinant fields

Radiative heat transfer in phase-change media is of great interest in many thermal applications in sciences and engineering involving internal melting or solidification. In these problems at high temperature, a mathematical model used to describe the heat transfer and phase change should also include equations accounting for thermal radiation. Using the integro-differential equation for the radiative

This study investigates the nonlinear dynamic response of an elastically constrained wheelset system, considering the impacts of excitation factors such as track irregularities and control parameters of the wheelset itself. A dynamic model of the wheelset system is established under both multiplicative and additive colored noise excitations, focusing on the system's stability and bifurcation behavior

Fluid-induced pressures usually alter in magnitude, direction, and application points during the action, which requires sophisticated computational modeling. Furthermore, multiscale design parameters have strong interdependencies. For the first time, this paper presents a comprehensive investigation on the hierarchical topology optimization considering pressure loads. In this framework, a smooth transition

Novel nonlocal continuum-based models are established to explore the mechanical behavior of multi-layered graphene sheets (MLGSs) with the aim of utilizing them for the in-plane transportation of electrons. To this end, the general in-plane transportation of electrons within GSs is suitably modeled by bi-directional electric currents accounting for deflections of GSs as the main influential factor

In this paper, an event-triggered prescribed-time distributed formation control method is designed for marine surface vessels with prescribed-time prescribed performance subject to compound uncertainties. Firstly, we introduce variable substitutions to simplify the mathematical model of marine surface vessels. Then, a prescribed-time extended state observer is constructed to estimate unmeasured velocities

Two-dimensional multi-phase interactions between a weakly ionised single-fluid plasma and an incompressible liquid layer are studied through detailed numerical simulations of the Navier–Stokes and Poisson–Nernst–Planck equations, with relevance to liquid cooling in nuclear fusion reactor divertors, as well as ionic wind cooling. The plasma–liquid interface is captured using the conservative phase-field

With the increasing development of intelligent transportation systems and advancements in aviation technology, the concept of Advanced Air Mobility (AAM) is gaining attention. This study aims to improve operational safety and service quality within Urban Air Mobility (UAM) through a trajectory-based operation (TBO). A multi-layer operational risk assessment model is introduced to capture the effects

Numerous bond-slip models have been proposed in the literature to elaborate on the behaviour between concrete and FRP. However, in most of these bond-slip models, the interfacial debonding fracture energy of the bond is not explicit. Furthermore, theoretical derivations of the experimental response of test samples from bond-slip models have often been calibrated with regression constants. This paper

The total variation (TV) model is a straightforward yet effective approach for noise reduction and blurring suppression in image processing. It necessitates converting the image matrix into a vector for problem-solving, which may compromise the preservation of the original image structure, especially in color images. In this paper, we propose a third-order tensor TV model for image deblurring in fractional-order

For the aerial docking problem, as one of the docking subjects, the active control of the drogue is very important. However, there are challenges such as multiple disturbances, inability to install accurate measurement sensors, and attitude constraints. Aiming at these problems, this paper proposes a trajectory anti-disturbance control method for the recovery drogue without flow angle measurements

This work presents a multiphysics mathematical modelling and numerical simulation of the slag melting process in an induction furnace, with a focus on the production of sustainable silicon through the EU SisAl Pilot project. The mathematical model incorporates electromagnetic, thermal and hydrodynamic phenomena in a coupled axisymmetric framework to simulate the melting of a CaO-SiO2 slag, a key component

In this paper, a robust integrated particle model is developed by coupling smoothed particle hydrodynamics (SPH) and peridynamics (PD) to deal with the fluid-structure interaction (FSI) problems involving violent free-surface flows and isotropic structural linear elastic deformations and failures. The partitioned approach is conducted in between a stable and accurate δ+-SPH fluid model and a non-ordinary

The paper aims to improve the efficiency of modeling interactions between slender deformable bodies that resemble the shape of fibers. Interaction potentials are modeled as inverse-power laws with respect to the point-pair distance, and the complete body-body potential is obtained by pairwise summation (integration). To speed-up integration, we consider the analytical pre-integration of potentials

This paper focuses on the construction of nonlinear dynamic models, specifically targeting continuous chaotic systems. It introduces an innovative approach to integrating state variables and uncertain variables to construct continuous chaotic systems. Initially, a unified construction method is proposed, combining state variables with a determinable amplitude matrix. The feasibility of this method

The twin helicopter slung system can be effectively utilized for handling rigid loads. Nevertheless, the intense oscillations caused by the coupling dynamics of two helicopters, cables, and slung loads complicate the transportation system, reduce transportation efficiency, and bring pilot challenges. While considerable research has been conducted on twin or multiple helicopters suspending a load, fewer

This paper presents a novel approach for controlling the DLR-HIT II robotic hand by leveraging physics-informed neural networks (PINNs) for torque and position control. This method eliminates the need for additional control inputs or external controllers, achieving high precision and simplified dynamics, which is validated through extensive simulations that closely replicate experimental conditions

This paper proposes a quasi-zero stiffness (QZS) isolator with three zero stiffness (ZS) points to cope effectively with mass load deviations. Most of the existing QZS vibration isolators are designed for a single mass. The vibration isolation performance of the isolator is significantly affected when the mass load deviates after the structure has been determined. The isolators designed in this paper

Many researchers have explored the complex time-dependent behavior of rock-concrete interaction in lined tunnels. However, for non-circular tunnel configurations, no analytical solution has been proposed yet. The presence of varying curvature along tunnel boundaries in non-circular tunnels leads to diverse effects on stress and strain components in both the lining and surrounding mass over time. As

To enhance acoustic piezoelectric energy harvesting at lower frequencies, this study proposes a coupled structure comprising a trampoline metamaterial and a Helmholtz resonator. The trampoline metamaterial incorporates periodically arranged composite resonant pillars embedded in a perforated thin plate. By designing a point defect in the metamaterial, vibro-acoustic energy can be intentionally confined

The mathematical modeling of compressible flows in both rigid and elastic pipes is discussed here. Both single- and two-phase flow modeling are considered in the present paper. First, the derivation of the models through the integration of the 3-D equations over the radially deformable inner pipe cross-section is described. Then, the Coleman-Noll procedure is used in order to formulate constitutive/closure

Cracking is one of the critical causes of material failure, and early damage management by implanting microcapsules in the matrix is practical. Existing studies have focused on the improvement of self-healing systems and preparation technology of microcapsules’, but have paid less attention to the issue of the probability of triggering the self-healing mechanism in microencapsulated self-healing composites

This research, based on the traditional theory of elastic wave propagation, employs the method of complex variable function method to solve the propagation problem of elastic SH waves in periodically inhomogeneous media. To enhance the seismic resistance of building structures, based on the wave impedance theory, the modulus and density of seismic functional gradient materials are designed to follow

This study employs a symplectic approach to investigate the buckling behavior of decagonal symmetric two-dimensional quasicrystal plates. The symplectic approach, known for its high flexibility and broad applicability, has become an essential tool in elasticity theory for addressing complex boundary conditions and material characteristics. Quasicrystalline materials exhibit unique elastic responses

Algebraic soliton interactions with a periodic or quasi-periodic random force are investigated via the Benjamin-Ono equation, which models internal waves in a two-layer fluid. The random force is modeled as a Fourier series with a finite number of modes and random phases uniformly distributed, while its frequency spectrum has a Gaussian shape centered at a peak frequency. The expected value of the

In this paper, an event-triggered safe H∞ control approach is investigated for nonlinear continuous-time systems with asymmetric constrained-input and state constraints. The proposed method is based on adaptive dynamic programming and addresses systems with completely unknown dynamics. Firstly, the unknown dynamics is identified using three neural networks. Secondly, a novel nonquadratic type function

Compressed sensing(CS) has been identified to significantly accelerate magnetic resonance imaging from the highly under-sampled k-space data. In this paper, based on low-rank plus sparse (L plus S) decomposition model, we propose a new dynamic MRI(dMRI) reconstruction model by introducing the tensor-ring(TR) rank and ?1 ? 2 norm constrained framework with an embedded Plug-and-Play(PnP) based regularization(TRLP)

Presently, there is worldwide consideration of Hydrogen pipelines as sustainable energy carriers as well as Carbon Dioxide pipelines for use in achieving net-zero goals through carbon capture and sequestration. For the purposes of planning expansions or new pipelines, typical design criteria like compressor maps, driver loads, etc., are used for simulations of pipeline capacity; however, it is often

The minimum acceleration stress directly affects the extrapolation accuracy and acceleration effect of the degradation model of the accelerated degradation test, which in turn affects the accuracy of the reliability assessment and the efficiency of the accelerated test. Aiming at the problem that the minimum acceleration stress is given empirically, this paper proposes a method to determine the minimum

The inverse heat conduction problem (IHCP) has significant applications across multiple disciplines. Traditional methods for IHCPs often require tedious and low-accuracy iteration, which frequently fails to meet engineering demands. Therefore, developing highly efficient and accurate methods for IHCP solutions is required. A novel meshfree least-squares stabilized collocation method (LSCM) for solving

A dynamic model of fiber polymer cylindrical shells covered with functional gradient protective coatings (FGCs) is proposed in this work to predict impact characteristics when low-velocity oblique impact loading is considered. The material properties of the FGCs attached to both the inner and outer surfaces of the structures is defined, and the related failure modes and different energy-absorbing mechanisms

The interaction between cracks is the main cause of material failure when the material contains multiple cracks. Using the classical Kachanov method and Fourier integral transformation, the thermoelastic behavior of one-dimensional hexagonal (1DH) quasicrystals (QCs) containing two asymmetric collinear cracks in a non-periodic plane is studied. Considering the interaction between cracks, the solutions

In this work bandgap formation and vibration attenuation properties in graded metastructure beams are studied. By using negative capacitance circuits and different grading laws on frequency spacing and arrangement of the piezoelectric and mechanical resonators, hybrid graded metamaterial beams are formed. This study emphasizes the potential of spatially graded metamaterials as a promising solution

Based on fractal theory, the tangential contact model for a joint surface, taking into account the contact angle between asperities, was developed by incorporating Gorbatikh's contact angle probability distribution function. Mathematical expressions for the stages of a single asperity and the entire joint surface were derived. The quantitative effects of fractal parameters, friction coefficient, material

The kinematic calibration of the robotic hand-eye system is formulated as solving the AX=XB problem, with calibration accuracy serving as the sole evaluation criterion. Whether the rotational and translational parts of the kinematic equations are calculated decoupled or not, being regarded as an important factor affecting the calibration accuracy, serves as a categorization criterion to form the separable

The extensive literature on the truck-drone routing problem (TDRP) from 2015 to 2024 is synthesized, driven by significant advancements in the field. The increasing volume of research indicates a sustained interest in the practical applications of TDRP in everyday scenarios. Despite the gap between theory and practice, the rapid development highlights its multi-disciplinary importance. A comprehensive

This article addresses the issue of civil aircraft weight and center-of-gravity position real-time estimation using the six-degree-of-freedom model with variable center of mass, and derives the explicit expressions for aircraft weight and longitudinal center-of-gravity. Firstly, the nonlinear six-degree-of-freedom aircraft model with center-of-gravity variations is established, where the moment correction

With the rapid development of urban rail transit systems, the issues of structural vibration and re-radiated noise in adjacent buildings have become increasingly prominent. This paper investigates the feasibility of a novel metamaterial-based Vibration Suppression Stories (VSSs) for mitigating train-induced structural vibrations from the perspective of vibration propagation. A Lumped Parameter Model

Reducing scanning time or radiation doses is a primary demand in computed tomography (CT) imaging. Few-view CT and limited-angle CT are considered as two effective imaging ways to meet this demand. However, they both face different challenges in practical applications, such as difficulties in technical implementation and image reconstruction. This study focuses on a special imaging strategy called

The third degree Moment-based Hermite model, which expresses a random variable as a cubic transformation of a standard normal variable, offers versatility in engineering applications. While its probability density function is not directly tractable, it is more complex to compute than the Gram-Charlier series, which, despite its simplicity, suffers from limitations such as positivity and unimodality

In this paper, the tracking control problem of gear transmission servo system with full-state constraints is studied, in which nonlinear dead zone and disturbance are considered. A backstepping tracking control strategy based on barrier Lyapunov function is proposed. First, a dynamic model of the gear transmission system considering nonlinear dead zone was established. Then, a disturbance observer

Fractional Differential Equations (FDEs) are essential tools for modelling complex systems in science and engineering. They extend the traditional concepts of differentiation and integration to non-integer orders, enabling a more precise representation of processes characterised by non-local and memory-dependent behaviours. This property is useful in systems where variables do not respond to changes

The mobility of devices in mobile Internet of Things (IoT) enables dynamic interactions, facilitating the spatiotemporal malware propagation. However, few studies have focused on accurately modeling and effectively controlling this form of malware propagation. To address this issue, we propose a theoretical framework that integrates patch-malware spreading dynamics with optimal patch allocation policy

In this paper, topology design, mathematical modeling and dynamic dimension synthesis methodology for a modular parallel robot (named ‘Y3’) with end-articulated structure and only revolute joints are systematically investigated. Firstly, to obtain the target configuration, the traditional explicit moving platform is topologically evolved into the end-articulated structure, and the degrees of freedom

The Maxwell Stress Tensor is a computationally efficient method for calculating the force and torque between two arbitrary collections of rigidly-connected permanent magnets, coils, and/or iron (soft magnet) segments, when using exact analytic magnetic field solutions. However, use of the tensor exacerbates numerical errors present in the closed-surface free space mesh of a region, whether that be