Bounce Modes Research Articles

Multi-objective parameter optimization of a novel hydraulically interconnected suspension for tri-axle mining dump trucks

The harsh working environment in the mining area has put strict requirements for the suspension system performance of mining dump trucks. To improve the anti-pitch and anti-roll ability of tri-axle mining dump trucks, a new type of hydraulically interconnected suspension system is proposed, including the left-right wheel interconnection in front axle and X-cross interconnection in mid-rear axle (X-HIS). The parameter sensitivity of X-HIS is analyzed, and the significant parameters are optimized. Specifically, a vehicle mechanical-hydraulic coupling model is established based on impedance matrix transfer method. The objective functions are obtained by combining the road spectral density matrix, and accuracy of the model is verified by the accumulator pressure experiment of the mining dump truck. Subsequently, the Morris method is applied to analyze the sensitivity of suspension parameters to the bounce, pitch, and roll modes vibration. The results indicate that the sensitive parameters are the initial pressure and volume of the front accumulator, the inner diameter of damping hole, the initial pressure of mid-rear accumulator, and the area ratio of upper and lower chamber of cylinder. The Pareto solution set shows that there is no conflict between the anti-pitch and anti-roll capabilities of X-HIS. The optimized X-HIS improves the ride comfort and anti-roll ability of the vehicle and balances the anti-pitch performance.

Unique Approach of Modern Automotive Exhaust System Mountings Design for NVH Improvement

<div>Minimizing vibration transmitted from the exhaust system to the vehicle’s passenger compartment is the primary goal of this article. With the introduction of regulatory norms on NVH behavior and emissions targets, it has become necessary to address these issues scientifically. Stringent emissions regulations increased the complexity of the exhaust system resulting in increased size and weight. Exhaust system vibration attenuation is essential not only from the vehicle NVH aspects but also for the optimized functionality of the subsystems installed on it. Based on earlier studies, this work adopts a more thorough strategy to reduce vehicle vibration caused by the exhaust system by adjusting it to actual operating conditions.</div> <div>To achieve this, a complete vehicle model of 22 DOF is considered, which consists of a powertrain, exhaust system, chassis frame, and suspension system. A method for evaluating static and dynamic vibration response is proposed. Through the use of the vehicle’s rigid body modes and actual field events, design indicators are carefully analyzed and validated. Based on actual operating conditions, the two main load cases that are taken into consideration are idling and the sweet spot operating zone. To define the sweet spot zone of the dominant vehicle/engine-operating scenario, the vehicle duty cycle is monitored experimentally.</div> <div>The baseline 22 DOF model results show a degradation in exhaust vibration performance in both load cases as its yaw and bounce modes are falling into the resonance region of the idle and sweet spot operating zone load cases, respectively. The acceleration reduction of nearly 10–20 dB in static events, and nearly 10 dB in dynamic events can be evident in the proposed model. The proposed system’s outcomes demonstrate an improvement in the eigenvalues of the yaw and bounce modes, which in turn enhances the vehicle’s overall NVH performance in both static and dynamic load cases. Thus, the study suggests that designers should consider the real field events’ load cases for modern exhaust system-mounting optimization to achieve improvement in NVH behavior, fuel efficiency, emissions performance, and durability aspects of the vehicle.</div>

Elastic discrete element analysis of natural vibration characteristics and settlement behavior of railway ballasted track

An elastic multi-body model of a ballasted track, consisting of an aggregate of ballast gravel and a single prestressed mono-block concrete sleeper, is constructed. Field-measured traffic load waveforms from an operational existing railway track are then applied to the left and right rail positions on the upper surface of the model using elastic discrete element method. The numerical results are subjected to frequency analysis to examine the relation between track settlement and natural vibration phenomena in ballasted tracks. The relative error between the measured and analyzed frequency values for the natural vibration modes of the ballasted track under 500 Hz is 2.23%, indicating that the current ballasted track model accurately reproduces the natural vibration characteristics of existing ballasted track structures. The analysis results reveal that the phenomenon of plastic deformation within the ballast layer occurs primarily in the upper part of the ballast layer, just below the sleeper. Additionally, for the bounce mode of the ballast layer in the frequency range of generally 100 Hz and below, it has been identified as the primary factor promoting significant vertical motion of the sleeper, along with the associated reverse U-shaped deformation of the sleeper, which accelerates the track structure degradation. Furthermore, when loosening occurs, the vibrational energy of this bounce mode increases, contributing directly to ballast degradation.

Bounce and contact mode regimes for drop impact on smooth surfaces: The influence of gas kinetics and electrostatics

When liquid drops impact on solid surfaces, an air layer forms in between the drop and the surface, acting as a cushion to mitigate the impact. In this work, we focus on delineating the bounce and contact mode regimes of impacting drops on smooth surfaces, specifically discerning whether drops rebound from the air layer or make contact with the solid surfaces, and pinpointing the precise contact modes between the drop and solid surfaces by resolving the gas film evolution and rupture. Our simulation model incorporates gas kinetics and electrostatics effects, both of which have been validated by experiments documented in the literature or theoretical models regarding thin film instabilities. We undertake a comprehensive review and categorization of the contact modes and elucidate how they change under different conditions of impact velocities, ambient pressures, and electric field intensities. We also provide some perspectives on the regime map for the lubricated surfaces, which contains an unresolved issue that the critical Weber number for bouncing-wetting transition is significantly reduced compared to the solid smooth surfaces like mica. These insights have noteworthy practical implications offering guidance for a wide range of scenarios, from normal-pressure environments to low-pressure conditions at high altitudes, encompassing high electric field conditions such as nanogenerators as well as low electric field conditions resembling glass surfaces with static electricity.

Impacting dynamics of nanodroplets on superhydrophobic surfaces decorated by a ridge

Reducing the contact time of impacting nanodroplets is of fundamental interest and importance due to its promising potential in various engineering applications, such as self-cleaning and anti-icing. In this work, nanodroplets impacting superhydrophobic surfaces decorated by a rectangular ridge are studied over a wide range of Weber number (We) and different sizes of the ridge via molecular dynamics. Six bouncing modes have been distinguished. The usage of the rectangular ridge significantly enhances the bouncing performance of nanodroplets, including enlarging the We range for bouncing and reducing the contact time. It is especially found that the rectangular ridge leads to an increased contact time compared with the flat surface in the moderate We region. The underlying mechanism of the differential effect of the rectangular ridge on the contact time is compressively elucidated by the retraction dynamics of distinct bouncing modes. Subsequently, the retraction models considering different retraction characteristics are developed for the unsplit case. To promote a universal understanding of the effect of the ridge on the retraction dynamics of nanodroplets, several typical ridge shapes (triangular, cylinder, and semi-circular) are further considered. The retraction models are extended and verified to consider the effect of the ridge shape by introducing the equivalent structure parameters. Based on such a universal understanding, a newly designed shoot-shaped ridge is proposed and can considerably reduce the contact time of unsplit nanodroplets in the moderate We region.

Disturbance observer-based sliding mode control of active vertical suspension for high-speed rail vehicles

Disturbance observer-based sliding mode control (SMC) on the active vertical suspension (AVS) is developed to suppress the car body’s rigid and flexible vibration to improve ride comfort for a high-speed rail vehicle. A vertical-dynamics-intended vehicle model is foremost built with the bounce, pitch, and bending mode of the car body involved. Two sliding surfaces and disturbance observers are then designed for SMC, which only require the car body states, obviating the bogies’ states. The observer is successful in estimating the effect of unknown track irregularities perturbation as well as externally straightforwardly excitations on the car body with good accuracy. Control efficacy is verified through comparison with passive cases and sky-hook controls. With modal damping below 2% in passive cases, the mode shape function, especially with large displacement at the suspension support, would enlarge the car body acceleration. Moreover, the longitudinal traction rod can significantly multiply the flexible vibration at certain speeds. Comparative studies indicate that SMC provides satisfactory outcomes in the rigid and bending vibration suppression when all the car body’s three modes are considered in the sliding surface. However, it requires a high-frequency response actuator and allows a tighter tolerance of the control time delay than the sky-hook control.

Research on railway vehicle modal parameter identification method based on drop impact load

This paper investigates the modal parameter identification technique utilizing a drop impact load. A 12-DOF mathematical model of a Railway Vehicle System (RWVS) was constructed, followed by theoretical calculations, simulation analysis, and tests with four different drop impact loads. The responses to these loads were inspected through FFT, and the modal frequencies of the RWVS were determined by the Peak Picking (P-P) method. The simulation demonstrated that four types of drop impact loads can activate the bounce, pitch, and roll modes of the RWVS. The theoretical calculation and simulation analysis revealed that the maximum error of modal frequency identification is no greater than 6.5%. The experimental results verified that the drop impact excitation method can be used to identify the modal parameters of a complex railway vehicle system, which is highly beneficial for the design and verification of the vehicle structure.

Self-Adaptive Droplet Bouncing on a Dual Gradient Surface.

Rapid detachment of impacting droplets from underlying substrate is highly preferred for mass, momentum, and energy exchange in many practical applications. Driven by this, the past several years have witnessed a surge in engineering macrotexture to reduce solid-liquid contact time. Despite these advances, these strategies in reducing contact time necessitate the elegant control of either the spatial location for droplet contact or the range of impacting velocity. Here, this work circumvents these limitations by designing a dual gradient surface consisting of a vertical spacing gradient made of tapered pillar arrays and a lateral curvature gradient characterized as macroscopic convex. This design enables the impacting droplets to self-adapt to asymmetric or pancake bouncing mode accordingly, which renders significant contact time reduction (up to ≈70%) for a broad range of impacting velocities (≈0.4-1.4 ms-1 ) irrespective of the spatial impacting location. This new design provides a new insight for designing liquid-repellent surfaces, and offers opportunities for applications including dropwise condensation, energy conversion, and anti-icing.

Influence of the Suspension Model in the Simulation of the Vertical Vibration Behavior of the Railway Vehicle Car Body

The evaluation of the vibration behavior of railway vehicle car bodies based on the results of numerical simulations requires the adoption of an appropriate theoretical model of the suspension which considers the important factors that influence the vibration level of the car body. In this paper, the influence of the secondary suspension model on the vertical vibration behavior of the railway vehicle car body is investigated, based on the results of numerical simulations on the frequency response functions of the acceleration, the power spectral density of the acceleration and the root mean square of the acceleration of the car body. Numerical simulation applications are developed based on a rigid-flexible coupled vehicle model with seven degrees of freedom, corresponding to car body vibration modes: bounce, pitch, and first vertical bending mode, and bogie vibration modes: bounce and pitch. Four different models of secondary suspension are integrated into the vehicle model, namely a reference model and four analysis models. Analysis models include systems through which the pitch vibration of the bogies is transmitted to the car body, influencing its vibration behavior and, respectively, a system that takes the relative angular displacement between the car body and the bogie and a system that models the transmission system of the longitudinal forces between the bogie and the car body are analyzed. The effects of these two systems on the vibration behavior of the railway vehicle car body are analyzed both for each system separately and together. In the conclusions of the paper, the influence of the secondary suspension model on the vibration level at the resonance frequencies of the vertical bending of the car body and the pitch of the bogie is pointed out. It also highlights the important contribution of the transmission system of the longitudinal forces between the bogie and the car body in transmitting pitch vibrations of the bogies to the car body, with effects on the vibration level of the car body at high speeds.

Kinematic Modes Identification and Its Intelligent Control of Micro-Nano Particle Manipulated by Acoustic Signal

In this paper, the dynamics of a micro-nano particle on the micro-thin plate driven by an acoustic signal was investigated, including the particle kinematics mode, kinematics equation, and trajectory control. According to Newton’s kinematic theorem, analyzing the forces acting on the particle, the kinematic modes of the driven particle are distinguished with specific mathematical conditions, which are classified as slide, bounce, and stable modes strictly planned on a thin plate area. Based on the theory of kinematic modal analysis, the simulation results reveal the distribution rules of particle motion modes against the driving signal or plate geometry. The particle kinematics equation governing the sliding movement on the thin plate was then derived in light of the interaction between the particle and driving signal, based on which, the particle trajectory was drawn and analyzed in detail. For the purpose of controlling the particle trajectory, the control problem was designed in accordance with a linear active disturbance rejection controller (LADRC). Further, a guidance law was proposed, and the corresponding controller was designed to realize the linear trajectory following.

Surface design of superhydrophobic parallel grooves for controllable petal bouncing and contact time reduction

This study numerically investigates the bouncing characteristics of impacting droplets on superhydrophobic sub-millimeter parallel grooves by the level-set method. Once the Weber number (We) is increased to a critical value (Wec), a unique petal-like droplet bouncing off the parallel grooves without horizontal retraction is found, dramatically reducing the contact time (tc) by up to ∼75%. Such a bouncing mode is attributed to the rectification of capillary energy stored in the penetrated liquids into upward motion. To achieve controllable petal bouncing, the coupling effects of impact velocity and surface geometric characteristics on tc and Wec are elucidated from the perspective of timescale, momentum, and energy. The numerical results indicate that narrowing the center-to-center spacing contributes to shortening tc and slowing down the growth of tc with We. In contrast, the effect of ridge height is negligible. By establishing the model of emptying time, the relationships of tc with impact velocity and geometric parameters are quantitatively identified. Furthermore, along with the strengthened anisotropic property, a large center-to-center spacing promotes the conversion of horizontal momentum into vertical momentum and suppresses the increment of surface energy, thus inducing the reduction in Wec. Distinct from known anisotropic surfaces in the previous work, the anisotropic property of parallel-grooved surface plays an opposite role in shortening tc. Finally, incorporating the energy balance approach, a semi-empirical model is developed to predict Wec, exhibiting good agreement with present simulation. This work provides physical insights into petal bouncing and inspires the design of textured surfaces to reduce contact time.

Bouncing modes and heat transfer of a dielectric droplet in the presence of an external electric field

A numerical investigation of droplet bouncing and heat transfer over a heated surface in the presence of an external electric field has been reported. The coupled set of governing equations including the electrostatic and incompressible Navier-Stokes equations, have been implemented in the finite-volume framework of OpenFOAM®. The coupled level set and volume of fluid (CLSVOF) approach has been used to capture the droplet interface. The influence of the electric field over the droplet dynamics and bouncing modes are systematically studied. Different bouncing modes are observed and they have been mapped with respect to the electric capillary number, CaE and Weber number, We. Two new modes have been identified at CaE=0.1. The Coulombic attraction at the solid-liquid contact line extends the total contact time of the droplet. The local electric field distribution depends on the droplet’s local curvature. The stronger distribution of electrostatic pressure near the tip of the droplet induces a stretching behavior. The stretched droplet, extended contact time and enhanced fluid circulation increase the heat transfer. This work provides a deeper understanding of droplet impact, bouncing dynamics and related heat transfer characteristics influenced by an external electric field.

Hydraulic integrated interconnected regenerative suspension: Modeling and mode-decoupling analysis

An innovative hydraulic integrated interconnected regenerative suspension system (HIIRS), which can simultaneously harvest suspension vibration energy and enhance the vehicle handling performance, is studied in this paper. One big challenge for the HIIRS is the mode-decoupling problem among the four vehicle vibration modes, namely bounce, roll, pitch, and warp modes. This paper comprehensively studied why and how the HIIRS could decouple the four modes. Specifically, the nonlinear fluidic model of the HIIRS was built and integrated with a 14DOF nonlinear vehicle model. Based on the model, the damping range and the coupling effects between the damping and the stiffness of the HIIRS were investigated. The roll and pitch stiffness of the HIIRS were calculated, where a novel piecewise-linearizing method was proposed to determine the analytic expression of the stiffness. Numerical experiments were conducted to demonstrate the mode-decoupling capability of the HIIRS and the influence of its parameters on the vehicle dynamics and the energy harvesting performances. In addition, the anti-roll, anti-pitch, and energy harvesting performances of the HIIRS were also studied and compared with a conventional off-road vehicle. The roll angle in a double lance change scenario and the pitch angle in a straight-line braking scenario could be respectively reduced by 34.42% and 28.91% when the initial system pressure in the HIIRS was 40 bar and the load resistance was 10Ω. The corresponding regenerative power was 87.69 W and 147.86 W for the two cases.

Detection of mode frequencies for spherical cavity embedded within a mild steel plate

The modern era of structures has observed a vast increase in non-destructive evaluation techniques in order to detect unwanted damages or porosities within the structure. Detection of defect frequencies will play a vital role in local defect resonance–based defect imaging in the future. In this paper, a technique for porosity and cavity detection in metals is discussed. A numerical investigation is carried out first on a square mild steel plate with a spherical cavity and a square mild steel block with multiple cavities. Different resonance frequencies and corresponding mode shapes in the case of the single cavity are calculated using steady state dynamic analysis. Six fundamental mode shapes are identified as Rocking (R), Torsional (T), Bouncing (B), 4-noded (4 N), 6-noded (6 N) and 8-noded (8 N) modes. Moreover, an explicit dynamic analysis is performed by exciting the model with a chirp signal for both cases of single and multiple cavities. The numerical study is supported by experimental results, performed on a mild steel plate embedded with a single spherical cavity and previously published literature. It is observed that the analytical, numerical as well as the experimental results obtained for all the modes are in close agreement with each other. The bouncing mode is found to be the promising one for pore imaging due to its uniform displacement across all the directions.

Railway noise reduction by periodic tuned particle impact damper with bounce and pitch-coupled vibration modes

In this study, a two-dimensional TPID (tuned particle impact damper) was proposed for reducing vibration via the interactions between the bounce and pitch vibration modes of the mass damper. To reduce the broadband vibration energy, the inelastic particle impact was utilized. The influence of the inelastic impacts on the rail vibration was investigated by the wave approach. To analyze the wave propagation characteristics, the periodic structure comprising the track and TPID was considered. The effects of the damper types, width, and loss factor on the complex wave propagation constant were investigated. The proposed TPID was applied to the actual rail. The track decay rate in the vertical direction increased by 3.2 dB/m. Accordingly, the proposed TPID effectively reduced the broadband rail vibration and allowed the tuning for optimal performance at multiple frequency ranges. With this actual installation on the track excited by the operating trains, the noise reduction performance both for moving passenger compartments and nearby residential area was verified. The sound levels in the residential area and in the passenger compartment decreased by 5.7 and 3.4 dBA, respectively. The proposed damper utilized the metallic components with advantages on rapid attachment and detachment. The proposed noise-control methodology is a cost effective vibration treatment to assure environment-friendly rail system.

The dynamic analysis-effect of orifice- of roll-coupled compacted hydro-pneumatic suspension subjected to typical based excitation

Adding flow channel between main and annular chambers in same strut of roll-coupled Hydro-pneumatic Inter-connected Suspension (HIS) can effectively avoid the negative hydraulic pressure caused by the high damping factor of connected pipes under high velocity condition. This flow channel is usually closed in previous research in HIS area. In this study, the effect of orifice between main and annular chambers in same strut to the dynamic properties of HIS under the different road excitations is investigated by the established AMEsim half-car simulation model. The bounce and roll displacement/acceleration of the sprung mass are used to evaluate the dynamic properties of HIS. The results illustrate that (1) the added orifice can reduce the roll displacement/acceleration with slight influence on the vertical displacement/acceleration under the transient and road loop excitations; (2) the added orifice will not change the resonance frequency of the bounce and roll modes; (3) comparing with the traditional HIS design (without the added orifices), the maximum roll transmissibility can decrease 30.17% with 2.89% increase of the maximum vertical transmission for the added orifice with 2 mm2 area. Overall, the results suggest that the proper size of the orifices will significantly increase the roll-stability properties with slight effect on the bounce mode under the road excitations.

Mapping between Surface Wettability, Droplets, and Their Impacting Behaviors.

Droplet behaviors on solid surfaces will influence numerous droplet-based applications ranging from nonwetting-preferred water-repellent surfaces to wetting-preferred spray coatings. Understanding droplet behaviors is complicated and centered on integrating multiple parameters that include surface properties, droplet initial states, and other boundary conditions. Previous studies have observed that droplet impacting performance by showing their underlying mechanisms is sensitive to either droplet or surface boundary conditions. While the holistic view about droplet behaviors is still missing, here we study the droplet impacting and spreading behaviors by systemically varying surface conditions and droplet input parameters through the combination of optical experiments, simulations, and theoretical approaches. The observation defines three droplet behavior modes: bouncing, semibouncing, and spreading modes through their dynamic phases, where the most contributing parameters can be identified as the combination of initial Weber number and surface wettability. The We-θ phase diagram suggested here will provide a guideline for surface engineering with desired droplet dynamic behaviors.

Light-powered self-excited bouncing of a liquid crystal elastomer ball

Light-powered self-excited motions of liquid crystal elastomers (LCEs) have great application prospects in the fields of actuators, soft robots, medical devices and micro-nano devices, and are capable of collecting energy directly from the environment to maintain its own motion without complex controller and additional battery. In this paper, a new light-powered self-excited bouncing system made up of LCE is originally established, and the self-excited bouncing is studied theoretically based on the well-established dynamic LCE model and Hertz contact theory. Numerical calculation shows that the LCE ball can develop into two motion modes: static mode and bouncing mode. The feedback mechanism of the bouncing mode is elucidated to be expansion-in-contact mechanism, of which the coupling of expansion and contact process enables light energy input from the environment to compensate for damping dissipation of the system. The phase diagrams and triggering conditions for provoking self-excited bouncing are quantitatively described for different system parameters. The results show that self-excited bouncing can be regulated by the system parameters, such as light illumination zone, gravitational acceleration, light intensity, equivalent modulus, contraction coefficient and damping coefficient. In addition, the system parameters have important effects on the amplitude and frequency of the self-excited bouncing of the LCE ball. It is expected that the study may provide some instructive suggestions for the design and motion control of active jumping machines.

Use of saturation diving technique for tunnel boring machine cutterhead intervention in the Tuen Mun–Chek Lap Kok Link Sub-sea Tunnel Project, Hong Kong

The entire Tuen Mun–Chek Lap Kok Link (TM-CLKL) was commissioned on 27 December 2020 and it comprises a 9km-long dual 2-lane carriageway between Tuen Mun and North Lantau, Hong Kong. Construction of the 5km-long sub-sea tunnels was carried out by two 14m diameter Tunnel Boring Machines (TBMs). The tunnel alignment for the TM-CLKL sub-sea tunnel section is in mixed ground condition with the first 500 m in mixed geology of slightly to moderately decomposed granite and completely decomposed granite (CDG), followed by soft ground condition with CDG, alluvial sand, alluvial clay and marine deposit. This mixed ground geology requires regular TBM cutterhead interventions to change the worn-out cutting tools during the tunnelling operation. As the tunnel alignment is up to 55 m below the sea level with the deepest seabed level at -21 mPD, in order to maintain the cutting face stability during the intervention, the intervention pressure could be up to 6 bars. This paper describes different techniques used for TBM interventions under the sea such as trimix bounce mode and saturation mode that appears first time in Hong Kong under a high hyperbaric pressure to change the worn-out cutting tools at the TBM cutterhead.

Dynamic network connectivity alteration predicts cognitive decline in Alzheimer’s disease spectrum

AbstractBackgroundBrian network integrity plays a pivotal role in the regulation of high‐order cognitive function and emotion for human brain. Disrupted functional coupling within‐ and between resting‐state networks (RSNs) are selectively vulnerable for neurodegenerative disease, such as Alzheimer’s disease. However, dynamic network alteration and its molecular pathological basis following the disease course in the AD spectrum still remain unclear. Currently, we integrated a new method combination of large‐scale network analysis and canonical correlation analysis (CCA) to explore dynamic spatiotemporal patterns within‐ and between RSNs and their significance in the AD spectrum.MethodWe analyzed data from the Alzheimer’s Disease Neuroimaging Initiative 1, GO and 2 datasets. A total of 160participants (59 cognitively normal (CN) participants, 49 patients with early mild cognitive impairment (EMCI), 28 patients with late mild cognitive impairment (LMCI) and 24 AD patients) completed fMRI scan, 3T MRI brain scan, CSF biomarkers and genes which strongly tied to AD risk detection and cognitive function assessment (MMSE and ADAS‐Cog scores). We studied group differences in within‐ and between RSNs. For cognitive function, genes and biomarkers, we did canonical correlation analysis between gene scores, cognitive scores , the biomarker levels and network variables across disease spectrum.ResultWe identified that all RSNs represented the increase connectivity within networks by enhancing inner cohesive ability, while seven out of ten RSNs were characterized by the decreased connectivity between networks, which indicates weaken connector ability among networks from the early stage to dementia. This dichotomous mode presenting large‐scale dynamic network abnormality was significantly correlated with the levels of molecular biomarkers (amyloid‐β, Tau, p‐Tau), cognitive performance, as well as accumulating effects of AD‐related ten genetic risk factors. This study implicated that spatiotemporal pattern of large‐scale network connectivity failure was not cascading, but represented a bouncing mode with the progression of cognitive decline. Taken together, we identified the determinants of the spread of disrupted network incoherence, molecular correlates, and summative effects of genetic variants on the RSNs.ConclusionThese findings provide novel insights for better understanding the mechanism underlying large‐scale network disruption linking molecular biomarkers and phenotypic variations in the AD spectrum.