In response to the challenges posed by uncontrolled amplitude during galloping and narrow effective bandwidth during vortex-induced vibrations in current energy harvesters, a novel wind-adaptable piezoelectric energy harvester utilizing a rigid-flexible compound blunt body (W-APEH) is proposed. The rigid-flexible compound blunt body improves environmental adaptability and power generation capacity

The velocity response spectrum (SV) plays an important role in the seismic design of structures that incorporate supplementary velocity-dependent dampers, which can be approximated by the pseudo-velocity response spectrum converted from the acceleration response spectrum (SA). However, the error of this approximation is significant for short and long periods. This paper aims to develop a model for

To improve the tribodynamic performance of ball bearings, micro-texturing has been widely used on bearing components and significant beneficial effects by using different shape, size and density of dimples at their contact zone has been reported in literature. However, behaviour of textures in vicinity of the contact zone in machine components particularly in ball bearings, where lubricant/grease is

This article focuses on improving the compliance, efficiency, and robustness of batch precision assembly of small-scale pegs flexibly absorbed by a suction cup. The main contribution is that a force–vision fusion fuzzy control method (FVFFC) is proposed to achieve precision assembly with unknown clearance or interference fit. Both visual and force features are designed to describe the state of the

To address performance issues caused by multi-source uncertainties of a rigid-flexible coupling hoisting robot (RFCHR), a performance optimization design method of the RFCHR considering cable deformation and random loading is proposed. The kinematic and dynamic models of the RFCHR are established, and the sources of uncertainty in cable deformation and random loading are analyzed, uncertain parameters

The primary intention of the work is to develop a simple and universal method for identifying time-varying nonlinear dynamic systems. No prior knowledge of the structure (Hammerstein or Wiener) and parametric form of static nonlinear characteristics is required. We limit ourselves to the class of so-called ’fading memory systems’, i.e., those that can be approximated with arbitrary accuracy using finite

In the field of active vibration control (AVC), it is difficult to use the classical filtered-x least mean squares (FxLMS) algorithm to solve the instability problem of active control system caused by the time-varying secondary path when the multiple channel coupling and the secondary path model are complex. Therefore, this paper proposes a new cost function based on the simultaneous perturbation stochastic

In recent years, with the deepening integration of digital twins (DT) and the Industrial Internet of Things (IIoT), solutions based on digital twins have been widely applied in IIoT scenarios. However, most existing solutions tend to overlook the latency issue during the interaction between mobile devices, such as industrial mobile robots (IMR), and their DTs while in motion. Excessive interaction

This study presents the Reconfigurable and Responsive Robot Manufacturing (R3M) architecture, a novel framework engineered to autonomously adapt to fluctuating product variants and demands within manufacturing environments. At the heart of R3M lies an integrated architecture that ensures a seamless data flow between critical modules, facilitated by an advanced communication platform. These modules

Point clouds are widely used to construct models of workpieces using 3D scanners, especially where high-quality robotic and automatic 3D scanning is required in industries and manufacturing. In recent years, Point Cloud Quality Assessment (PCQA) has garnered increasing attention as it provides quality scores for entire point clouds, addressing issues such as downsampling and compression distortions

Over the past decade, computer vision-based measurement approaches have been proposed to achieve non-contact structural displacement measurement. In particular, phase-based optical flow (PBOF) provides accurate dynamic measurements but is limited to estimating small displacements. Conversely, template matching can measure large-scale displacements but suffers from pixel resolution constraints. This

Assessing the performance of earthquake-resistant structural and geotechnical systems is crucial for achieving a desired reliability level and enhancing the resilience of the built environment in seismic-prone regions. Nonlinear dynamic analyses are widely used to quantify structural and geotechnical performance. Still, they require an accurate representation of nonlinear behaviours and proper modelling

In this study, we present a novel topology-optimized design of a two-dimensional cavity-free mechanical metamaterial with a negative coefficient of thermal expansion. We challenge the prevailing hypothesis that cavities are necessary for achieving negative coefficients of thermal expansion. The proposed metamaterial is a periodic lattice of a topology-optimized unit cell comprising three distinct solid

A robust inverse method for the complex wavenumber space (complex k-space) extraction is essential for structural vibration and damping analysis of two-dimensional structures. Most existing methods suffer from extracting the reliable complex k-space of plates in the presence of realistic uncertainties, especially for plates with low damping properties. To this end, this paper presents a new method

Multiple-input multiple-output (MIMO) tests are used to replicate environmental conditions on dynamic systems in a lab setting. MIMO tests allow responses at multiple locations to be replicated far better than possible with normal single input tests. However, achieving a desired response at multiple response locations is affected by various factors. Specifying test tolerances based on multiple responses

Virtual Reality (VR) and Augmented Reality (AR) technologies have been separately applied to enhance a wide range of design and manufacturing operations across various industries. Most VR applications are primarily focused on product prototyping and personnel training, whereas AR is commonly used to facilitate manual operations in manufacturing such as assembly and maintenance tasks. This study proposes

To enhance the accuracy of excavator external forces estimation, a data-physics hybrid-driven excavator external forces estimation method is proposed. MultiLayer Perceptron (MLP) model is applied for nonlinear component modeling and is used to compensate for Rigid Body Dynamics (RBD) models. Gaussian Process Regression (GPR) model is developed to estimate the external forces and uncertainties based

Structural interstory drift estimation is crucial, offering direct insights into structural conditions under extreme loading scenarios. However, achieving precise estimations poses significant challenges. This paper introduces a novel interstory drift estimation approach that integrates Kalman filter and wavelet-based denoising techniques with acceleration and vision-based measurements at varying sampling

Recent shock-protection technologies have leveraged elastic instability in nonlinear bistable mechanisms. These innovations include a bistable shock isolator (BSI), which uses a zero-frequency singularity to delay and mitigate force transmission. However, a well-escape accompanying the singularity of the BSI has a critical drawback as the well-escape alters the initial conditions, which precludes repetitive

In automated fiber placement (AFP), addressing the continuous motion planning challenge of redundant layup manipulators in complex environments, this paper proposes an offline redundancy optimization algorithm based on improved RRT* (Rapidly-exploring Random Trees). This algorithm maximizes the utilization of kinematic redundancy to derive smooth joint trajectories devoid of collisions and singularities

Three-dimensional isolation system (3DIS) has been increasingly applied to civil structures with small height-width ratios, but is rarely employed in the multistory and high-rise buildings due to the lack of efficient control strategy for the rocking effect. In this paper, a simplified analysis model of 3DIS was established firstly to bring insights into the coupled motion mode caused by the rocking

While existing models have achieved significant progress on fault diagnosis tasks, what interpretable temporal dependencies they capture to resist noise remains unclear. Previous studies have ignored the inherent non-stationary property of fault data, which is the basis for capturing reliable temporal dependencies under heavy noise operating scenarios. To tackle the aforementioned problems, we propose

The connection between micro-level characteristics and macroscopic properties in granular heat transfer and mechanics is fundamental and crucial. This study proposes a novel discrete element approach incorporating granular heat transfer, contact bonding, and granular stress tensor models to investigate the mechanical and thermal responses of continuum media composed of constituent spheres. Eight benchmark

Spectral amplitude modulation (SAM) method, as an automated and empirical nonlinear filtering approach, has shown great promise for rotating machinery fault diagnosis. However, due to the inherent shortcomings of Fourier transform in SAM, leading to significant errors in the edited amplitude, also it is easy to fail with selecting the optimal weight value manually under intense background noise. To

The rapid development of electric drives technology presents new challenges in the domain of vibration and noise suppression within gear trains. Dynamics modeling serves as a crucial method for studying vibration and noise; however, a deficiency exists in adequately considering the interaction between tribology and the dynamics of gear drives in current research endeavors. This article proposes a unified

In this work, we address Nonlinear System Identification (NSI) of geometrically nonlinear structures using experimental response data. Specifically we consider nonlinear structures with large inertia effects. A laboratory scale cantilever-type beam structure is considered, which is chosen for its large inertial effects. Free decay data is gathered from the experimental cantilever-type beam system using

Spectral Correlation (SC) has become a critical analytical instrument for assessing the second-order cyclostationarity (CS) in signals, especially for mechanical vibration signals. Nonetheless, the computational demand for computing SC is considerable. Built upon the Smoothed Cyclic Periodogram (SCP), a consistent estimator named Fast Smoothed Cyclic Periodogram (FastSCP) is proposed to address this

In emerging manufacturing facilities, robots must enhance their flexibility. They are expected to perform complex jobs, showing different behaviors on the need, all within unstructured environments, and without requiring reprogramming or setup adjustments. To address this challenge, we introduce the A3CQP, a non-strict hierarchical Quadratic Programming (QP) controller. It seamlessly combines both

Deep learning methods have attracted considerable attention in the field of chatter detection due to their exceptional feature extraction and identification capabilities. However, it is challenging to adapt these methods to diverse machining conditions with limited sensor resources. In addition, the computational efficiency of these methods is compromised by their complexity, resulting in a reduced

In view of the following problems existed in the data-driven resistance spot welding (RSW) quality judgment methods: relying on expert experience, resulting in a high misjudgment rate; affected by the initial value, it is easy to fall into the local extreme point; multiple parameters needed to be modulated to increase the training time of the model. Therefore, this paper proposed a RSW quality judgment

For the real-time characterisation of an inhomogeneous impact inhibiting constraint such as downhole rock layers, an unconventional method using machine learning (ML) and drill-bit vibrations is investigated. An impact oscillator with one-sided elastic constraint is employed in modelling the bit-rock impact actions. Measurable drill-bit dynamics, such as acceleration, were acquired and processed into

The increase in the speed of high-speed trains and the widespread use of lightweight vehicle body technology have made vehicle systems more sensitive to aerodynamic excitation. However, few studies have focused on the worsening of passenger ride comfort, as opposed to just safety, when trains pass along windy railway lines. This study first analyzes the connection between flow structure and aerodynamic

4H-SiC wafer with alloy backside layer is gradually applied in power devices. However, the laminated structure presents various challenges in manufacturing. In this study, a model for brittle-ductile transition in grinding of laminated materials is established and verified by grinding experiment to ensure the complete removal of the alloy backside layer while achieving ductile removal of the 4H-SiC

In this study, inspired by the mechanical metamaterials with bandgap properties, a new type of meta-arch structure (MAS) for the attenuation of elastic waves is proposed. In this metastructure, the reinforcement cage, typically employed to enhance the tensile properties of building materials, has been redesigned and transformed into a new structure containing circular tubes with embedded resonant microstructures

A novel mixed finite element method is developed and implemented for analyzing the vibration and buckling behavior of general composite beams which consists both transversely layered and axially jointed materials. The governing state-space equations are derived using the Hamilton's principle, where both displacements and stresses are treated as fundamental variables. This semi-analytical method uses

The elastic matrices of extremal metamaterials have one or more zero eigenvalues, allowing energy-free deformation modes. These elastic metamaterials can be well approximated by manufactured microstructures. They can exhibit an unprecedented capacity to manipulate bulk and surface waves, which are unavailable with conventional solids due to the easy deformation modes, as already exemplified by pentamode