Low-frequency Response Research Articles

Physically Guided Estimation of Vehicle Loading-Induced Low-Frequency Bridge Responses with BP-ANN

The intersectional relationship in bridge health monitoring refers to the mapping function that correlates bridge responses across different locations. This relationship is pivotal for estimating structural responses, which are then instrumental in assessing a bridge’s service status and identifying potential damage. The current research landscape is heavily focused on high-frequency responses, especially those associated with single-mode vibration. When it comes to low-frequency responses triggered by multi-mode vehicle loading, a prevalent strategy is to regard these low-frequency responses as “quasi-static” and subsequently apply time-series prediction techniques to simulate the intersectional relationship. However, these methods are contingent upon data regarding external loading, such as traffic conditions and air temperatures. This necessitates the collection of long-term monitoring data to account for fluctuations in traffic and temperature, a task that can be quite daunting in real-world engineering contexts. To address this challenge, our study shifts the analytical perspective from a static analysis to a dynamic analysis. By delving into the physical features of bridge responses of the vehicle–bridge interaction (VBI) system, we identify that the intersectional relationship should be inherently time-independent. The perceived time lag in quasi-static responses is, in essence, a result of low-frequency vibrations that are aligned with driving force modes. We specifically derive the intersectional relationship for low-frequency bridge responses within the VBI system and determine it to be a time-invariant transfer matrix associated with multiple mode shapes. Drawing on these physical insights, we adopt a time-independent machine learning method, the backpropagation–artificial neural network (BP-ANN), to simulate the intersectional relationship. To train the network, monitoring data from various cross-sections were input, with the responses at a particular section designated as the output. The trained network is now capable of estimating responses even in scenarios where time-related traffic conditions and temperatures deviate from those present in the training data set. To substantiate the time-independent nature of the derived intersectional relationship, finite element models were developed. The proposed method was further validated through the in-field monitoring of a continuous highway bridge. We anticipate that this method will be highly effective in estimating low-frequency responses under a variety of unknown traffic and air temperature conditions, offering significant convenience for practical engineering applications.

Effect of stratification on the combustion behavior and dynamic response of a bluff-body stabilized ammonia–hydrogen flames with radial staging

The present study deals with the flames of ammonia–hydrogen blends that form a prospective fuel for power generation in practical devices. In particular, the spatial flame dynamics of the bluff body stabilized laminar and stratified ammonia–air/hydrogen–air mixtures with acoustic excitation are considered. For this, we consider a radially staged burner consisting of two concentric tubes namely, the inner and outer tubes with the bluff body housed by the former. Two annulus passages are formed between (i) the inner and outer tube, and (ii) the inner tube and bluff body in which premixed hydrogen–air and ammonia–air mixtures are supplied, respectively. The stratification is controlled by varying the upstream location of the inner tube about the burner exit, termed mixing length taking the values namely, 20 mm (stratified), 60 mm, and 100 mm (unstratified). Time-resolved images of the flames are obtained using OH* (320 ± 10 nm) and NH2* (632 nm ± 10 nm) filters. For the unforced stratified flames, the flames are narrower and the spatial separation between OH* and NH2* region increases towards rich NH3/air mixtures ( ϕNH3–air) compared to the unstratified flames. In addition, the mean spatial OH* is relatively localized for the unforced stratified flames. For any operating condition of the flames, the forced flame response is significant for frequencies < 120 Hz. The rich stratified flame exhibits a higher response at a frequency of ∼ 40 Hz compared to the unstratified flame having a flatter response. The forced flames accompany lobed spatial patterns in OH* and NH2* for richer ϕNH3–air. The flame oscillation registers a non-sinusoidal oscillation for the rich stratified flame compared to flames of any other condition. The main effect of stratification is the alteration of flame shape resulting in a low-frequency response for which regions of significant flame flapping coincide with regions of peak flame OH*.

A dual-modified implicit time integration method for three-dimensional impact modelling within the framework of the SBFEM

This paper presents a dual-modified implicit time integration method (DMITIM) for three-dimensional impact modelling within the framework of the scaled boundary finite element method (SBFEM). Controlled by a single parameter, this method effectively dissipates high-frequency responses in impact problems without affecting low-frequency responses, ensuring time integration stability. To address the issue of false oscillations during impacts, additional Lagrange multipliers are introduced to supplement the velocity and acceleration corrections at each time integration step. For nonmatching meshes, by leveraging the mesh flexibility of the SBFEM, a rapid and straightforward remeshing method is utilized to establish a node-to-node contact scheme. The numerical results demonstrate that the DMITIM significantly reduces false oscillations in the velocity and contact force during impact events. It also showcases the flexibility of the SBFEM in handling nonmatching meshes. The combination of the SBFEM with the DMITIM provides enhanced simulation accuracy and stability for impact problems compared to the results from ABAQUS using the HHT-α time integration algorithm.

The impact mechanisms of intermediate water depth on the coupled dynamic responses of large-capacity floating wind turbines

ABSTRACT The currently planned floating wind farms in China mostly have water depths in the intermediate range. Therefore, investigating the impact mechanisms of intermediate water depths on the coupled dynamic responses of floating wind turbines is of significant importance. In comparison to deep water, mooring systems in intermediate water depths are more prone to experiencing catenary shape loss and stiffness. The contribution of difference-frequency effects increases with decreasing water depth, resulting in a more substantial impact on low-frequency responses. The Full Quadratic Transfer Function (QTF) method accurately captures low-frequency responses. Placing clump weights in the bottom section of the mooring line effectively restricts the displacement range of floating turbines while maintaining average fairlead tensions at levels similar to the other two forms. On this basis, focusing on the most optimal mooring system performance, experiments were conducted to validate the coupled dynamic responses of floating wind turbines in intermediate water depths.

A frequency-domain hydroelastic approach for modeling and stochastic dynamic analysis of pontoon-type floating bridges

In recent years floating bridges have been extensively studied owing to their potential application for crossing wide and deep fjords. An efficient approach for analyzing stochastic hydroelastic responses of floating bridges is valuable for fast assessment of various load effects for preliminary design. This study develops a frequency-domain approach for hydroelastic analysis of pontoon-type floating bridges subjected to wave loads. The frequency-dependent motion equation of the multi-pontoons is established based on the potential flow theory and linearized Morison’s equation for viscous damping. The structural dynamics of the elastic bridge girder are represented utilizing a beam model with excitations transferred from each pontoon. The proposed method is applied to an end-anchored curved floating bridge, with highlights on the verification against a validated time-domain simulation tool. Convincing agreements are found in terms of the eigenvalues, wave excitation loads, and response statistics. The method shows high fidelity with an accurate capture of the linear wave-frequency responses as well as the low-frequency resonances. A further discussion demonstrates that the wave viscous damping restrains low-frequency resonant responses, whereas the hydrodynamic interactions of pontoons induce more resonant peaks in the wave frequency.

Contrasting Ultra-Low Frequency Raman and Infrared Modes in Emerging Metal Halides for Photovoltaics.

Lattice dynamics are critical to photovoltaic material performance, governing dynamic disorder, hot-carrier cooling, charge-carrier recombination, and transport. Soft metal-halide perovskites exhibit particularly intriguing dynamics, with Raman spectra exhibiting an unusually broad low-frequency response whose origin is still much debated. Here, we utilize ultra-low frequency Raman and infrared terahertz time-domain spectroscopies to provide a systematic examination of the vibrational response for a wide range of metal-halide semiconductors: FAPbI3, MAPbI x Br3-x , CsPbBr3, PbI2, Cs2AgBiBr6, Cu2AgBiI6, and AgI. We rule out extrinsic defects, octahedral tilting, cation lone pairs, and "liquid-like" Boson peaks as causes of the debated central Raman peak. Instead, we propose that the central Raman response results from an interplay of the significant broadening of Raman-active, low-energy phonon modes that are strongly amplified by a population component from Bose-Einstein statistics toward low frequency. These findings elucidate the complexities of light interactions with low-energy lattice vibrations in soft metal-halide semiconductors emerging for photovoltaic applications.

Dynamics of Two Episodes of High Winds Produced by an Unusually Long-Lived Quasi-Linear Convective System in South China

Abstract Using radar observation and convection-permitting simulation, this work studies the storm-scale dynamics governing the generation of two episodes of high winds by an unusually long-lived quasi-linear convective system (QLCS) in South China on 21 April 2017. The first episode of high winds occurred at the apex of a bowing segment in the southern QLCS due to the downward transport of high momentum by a descending rear-inflow jet (RIJ). The RIJ was initially elevated which was generated as low-frequency gravity wave response to the thermal forcing in the QLCS leading convective line. It descended to the surface owing to the enhancement of low-level diabatic cooling which strengthened the downdrafts at the RIJ leading edge. The vertical momentum budget revealed that the downdrafts were initiated by the negative buoyancy of the cold pool and strengthened by the weakened buoyancy-induced upward pressure gradient force in the boundary layer and enhanced hydrometeor loading above. The second episode of high winds occurred in the decaying stage of the QLCS which, however, redeveloped as its northern part interacted with an intensifying large-scale shear line to the east. A zonal convective line developed along the shear line and finally merged with the QLCS. The merger greatly enhanced the low-level convergence, leading to the downward development of the line-end vortex via vertical stretching of vertical vorticity. The area of high winds was notably increased by the superposition of the ambient translational wind with the vortex rotational flow. The findings provide new insights into the generation of high winds by the QLCS-MCS merger, highlighting the importance of low-level vortices in addition to the RIJ. Significance Statement Quasi-linear convective systems (QLCSs) are prolific producers of high winds at the surface. While conceptual models have been established for high winds produced by single QLCSs, this is not the case for the high winds generated by QLCSs merging with other convective systems. This work revealed different dynamics for two episodes of high winds produced by a long-lived QLCS merging with an MCS in South China. The first episode resulted from the descending rear-inflow jet (RIJ) as in the case of single QLCSs. The second and stronger one was due to the superposition of ambient flow with a line-end vortex that developed downward given the enhanced low-level convergence by the merger. This finding sheds light on the importance of mergers in high-wind generation which has even greater damaging potential than the RIJ.

High-dynamic steering control of the pump-controlled electro-hydraulic steering system for heavy vehicles with active disturbance suppression

Low-frequency response, strong nonlinearity and unknown disturbances are the main challenges faced by the engineering application of the pump-controlled electro-hydraulic steering systems (EHSSs) for heavy vehicles. To solve the above problems, an active disturbance suppression controller is proposed based on a variable rate reaching law (VRRL) and a terminal sliding mode observer (TSMO) in the framework of the sliding mode control. This controller is unique because, the VRRL introduces a nonlinear activation function, which enables smooth switching between multiple reaching rates, effectively improving the response speed and the disturbance rejection performance of the pump-controlled EHSS. Furthermore, an adaptive incomplete disturbance compensation control strategy is proposed by incorporating a TSMO to further improve the accuracy and robustness of the steering system, which employs a VRRL-based TSMO to realize accurate estimation of the lumped disturbance in finite time, and avoids controller overcompensation by selecting a preferred disturbance compensation coefficient. The stability analysis demonstrates that the proposed controller effectively suppresses the lumped disturbance and reduces the convergence domain of the steering system. A pump-controlled EHSS experimental bench is constructed, and a series of experiments are conducted with various steering frequencies and load conditions, which validate the ability of the proposed controller to achieve high-precision dynamic steering in all-terrain conditions of the pump-controlled EHSS for heavy vehicles.

A wideband vibration sensor with piecewise nonlinear and up-frequency coupling strategy for mechanical fault monitoring

Vibration analysis using vibration sensors is an effective method of monitoring mechanical faults. However, most current vibration sensors have a narrow working frequency range and a low-frequency vibration response. Therefore, broadening the frequency band to detect high-frequency vibration signals is imperative. This paper proposes a self-powered vibration sensor based on a broadband hybrid generator (VS-BHG) that incorporates a piecewise nonlinear and up-frequency coupling strategy through collisions between the suspension and fixed part, thereby effectively expanding the operational frequency range. By implementing this strategic approach, the VS-BHG can effectively capture the vibration energy across a broad frequency spectrum ranging from 5 to 38 Hz and exhibit a robust linear response to acceleration within the frequency range of 20–1600 Hz. A machine running state monitoring system based on the VS-BHG is established, enabling the recognition of 16 different running states and fault types in industrial fans with an accuracy rate of 98.38 % using a deep-learning model. This paper presents an efficient and viable method for monitoring broadband mechanical fault.

A rotary self-sensing magnetorheological damper based on triboelectric nanogenerator

A rotary self-sensing magnetorheological (MR) damper(RSMRD) based on a triboelectric nanogenerator is proposed in this study, which can provide variable torque and state self-sensing without a power supply. Compared with traditional self-sensing devices, the sensing part of RSMRD has the advantages of small size, no external power supply, and good low-frequency response. The feasibility of the angular velocity self-sensing (AVS) function is verified through theoretical derivation and experimental verification. The experimental results demonstrate a linear relationship between the output voltage generated by the AVS component and the rotational speed of the rotating shaft. Additionally, the torque characteristics of the rotary self-sensing MR damper are tested, revealing a torque generation of approximately 9.26 N ⋅ m at a current of 1.6 A. Furthermore, a fuzzy control algorithm for vehicle braking is proposed, based on the model parameters of RSMRD. The simulink software is used to establish a dynamic model of 1/4 car braking, with an initial braking speed of 15 m s−1. The results indicate that the vehicle comes to a complete stop after 1.64 s, with a braking distance of 10.93 m. Throughout the braking process, the vehicle slip rate remains close to the optimal slip rate of 0.2.

Enhancing the absorption performance of minimal surface-based bulk absorbers via symmetry-breaking

The examination of Triply Periodic Minimal Surfaces (TPMSs) in the context of their acoustic dampening qualities has established them as viable alternatives to conventional porous absorbers. By adjusting the structure's porosity, one can significantly alter the TPMSs' acoustic absorption characteristics. Traditionally, enhancing sound absorption has involved decreasing porosity, which unfortunately increases the material's weight. In this study, we introduce a different approach to alter their absorption performance without altering their overall relative density. Our approach relies on leveraging the mathematical formulation of such structures to break their underlying geometrical symmetry. This symmetry-breaking results in altering their sound absorption characteristics while introducing an anisotropic acoustic response. In this paper, we present the mathematical design and fabricate the samples using the Fused Filament Fabrication (FFF) additive manufacturing method. The sound absorption characteristics of the printed samples are tested using a two-microphone normal incidence impedance tube setup. The presented results demonstrate that symmetry-breaking provides a viable route towards improving the low-frequency response of TPMS sound absorbers.

Inverse design of growth-inspired irregular architected materials for programmable properties

Biomimetic metamaterials have gained increasing attention due to their exceptional characteristics such as high toughness, robust strength, and effective noise reduction. However, their complex and irregular nature presents challenges in tailoring their mechanical properties for specific applications. This study proposes a novel dual-network approach to overcome these challenges. The approach involves creating a forward model to accurately predict the mechanical properties and interconnectivity of the metamaterial without the need for growth and homogenization processes. Additionally, an inverse model is utilized to accurately predict designs for desired anisotropic stiffness. Compared to traditional bidirectional networks, our approach demonstrates superior accuracy in designing elastic properties. Our results also show that the metamaterial exhibits a broad low-frequency response while maintaining exceptional load-carrying capacity, making it a promising solution for designing low-frequency vibration suppression metamaterials.

Forced vibration analysis of a beam-plate system coupled through multiple nonlinear single-freedom-degree systems

A beam-plate coupling system is widely used in the construction of different frameworks across industries according to engineering application requirements. In this paper, a nonlinear single-degree-of-freedom structure is introduced as a coupling element between the beam and the plate. Therefore, a coupling system connected through a plurality of the nonlinear single-degree-of-freedom structures is proposed with exposure of its operational mechanism and the dynamic behavior analysis as required. The nonlinear coupled governing equations of the beam-plate system with series nonlinear energy sinks are established according to the Hamilton principle and solvable by the Galerkin truncation method. Meanwhile, the nonlinear characteristics of transverse vibration of the coupling system are studied for discussing the effect of nonlinear stiffness on a low-frequency response of the beam-plate system. Further, the transverse vibration of the system may vary with changes in the nonlinear stiffness, the external viscous damping, and the motion mass of the nonlinear single-degree-of-freedom structures. Accordingly, the variations along with these factors are investigated. The results indicate that a reasonable nonlinear single-degree-of-freedom structure can have a significant influence on the transverse vibration characteristics of the beam-plate system.

A poly(L-lactic Acid)-based flexible piezoelectric energy harvester with micro-zigzag structures

Piezoelectric energy harvester (PEH) holds great potential for flexible electronics and wearable devices. However, the power conversion efficiency of flexible PEH (fPEH) has often been a limiting factor, especially under variable excitation. Herein, we propose a practical solution: a poly(L-lactic acid)-based fPEH with 3D-printed micro-zigzag structures. This design not only broadens the operational bandwidth and enhances low-frequency response but also offers a tangible improvement in the power conversion efficiency of fPEH. The micro-zigzag structure was designed and fabricated using a digital light processing 3D printing technique with acrylates, a method that is readily accessible to researchers and engineers in the field. Mechanical properties of the 3D-printed acrylic elastomers with different compositions were investigated to obtain the material parameters, and then fPEH with the sandwich structure was fabricated via sputtering and packaging. Subsequently, numerical simulation was conducted on the micro-zigzag structures to determine the structure sizes and oscillation frequencies of fPEH. Finally, four micro-zigzag structures with 3-, 4-, 5- and 6 mm lengths were tested to obtain oscillation frequencies of 51, 37, 22, and 21 Hz consistent with the simulation. The output voltages of fPEH are 11–30 mV with the load ranges of 60–100 MΩ. Stability evaluation showed that the fPEH can work under low frequency (<100 Hz) and broadband conditions. The micro-zigzag structure provided new insights for the design of fPEH, paving the way for more efficient and practical energy harvesting solutions in the future.

Numerical Calibration of the Mooring System for a Semi-Submersible Floating Wind Turbine Model

Abstract Numerical modeling of the floating offshore wind turbine (FOWT) dynamics plays a critical role at the design stage of a floating wind project. Still, there exist challenges for verification of efficient engineering models against experimental results. Recently, an experimental campaign was carried out for a 1:96 downscaled model of the OC4-DeepCWind semi-submersible platform with mooring lines made of fiber ropes and chains. Leveraging the results of this campaign, this paper focuses on the development and calibration of a numerical model for the semi-submersible platform with a focus on the dynamic responses under bichromatic waves. In the numerical model, the hydrodynamic loads are modeled based on the potential flow theory with Morison drag. The lumped mass method is applied to model the mooring system. Both free decay tests and bichromatic wave conditions are considered in the model calibration process, and key uncertain parameters (e.g., mooring line length) that affect the response have been identified and discussed. Using the proposed calibration procedure, we establish a reasonably good numerical model for prediction of the platform motion and mooring dynamics. The low-frequency responses of the platform under bichromatic waves are well-captured. These outcomes contribute to the development of efficient numerical FOWT models under experimental uncertainty.

Response prediction and probabilistic analysis of the vehicle-ballasted track system considering track irregularity based on long-short term memory neural network

It is necessary to efficiently and accurately predict the dynamic behavior of the train-track system subjected to massive random track geometric excitations for system evaluation and maintenance. This paper proposed an engineering practical approach for the train-track system behavior prediction by integrating the deep learning surrogate model-based long-short term memory (LSTM) and physical model of the train-ballasted track interaction (TBTI) system, and then the generalized probability density evolution method (GPDEM) is introduced to achieve the probabilistic assessment of the TBTI system under limited track irregularities, where the track irregularity probability model (TIPM) coupled with generalized-F discrepancy points sets is employed to compress the track irregularity sets to reduce the number of system responses (as training target) but without loss of the responses completeness, therefore, it can promote the efficiency and accuracy of training model. The prediction performance of the surrogate model is illustrated by comparing the time-frequency domain information, mean and standard deviation of the responses obtained by the physical model and surrogate model. The results indicated the proposed method can accurately predict the system response, especially the low and medium frequency response below 50 Hz, and improve the efficiency of stochastic analysis for the TBTI system by approximately 20 times. Furthermore, the applicability of the proposed method is further examined by investigating the influence of probability levels of track irregularity and train speeds on train performance. Its extended model is also implemented to predict the response of systems induced by any measured track irregularity in real-time, which promotes the generalization capability of the proposed surrogate model.

Numerical Modeling and Dynamic Response Analysis of an End-Anchored Floating Bridge With a Damaged Pontoon Under Repair Operation

Abstract Floating bridges face potential hazards due to ship collisions throughout their operational lifetime. In a situation where a pontoon is significantly damaged from an accident, a floating drydock may be used to compensate for the lost buoyancy and provide a dry atmosphere for operations. As the repair might take months, a primary concern is whether the repair can be in-site conducted without shutting down the road traffic. This study aims to investigate the feasibility of using a drydock for the repair. The numerical model of the in-operation damaged bridge is established for a comparative dynamic analysis with the intact end-anchored bridge. Eigenvalue analysis is conducted, and pendulum modes of oscillation are found with an eigen-period of around 15 s. The dynamic responses are analyzed through a series of fully coupled time-domain simulations under various environmental conditions. The results indicate that the standard deviation of the moment about the girder weak axis increases significantly at the damaged pontoon axis due to the excitation of low-frequency resonant response. Swell wave loads might induce dynamic amplification to the damaged bridge, even with a relatively small wave height. In addition, the internal stress of the bridge girder is investigated and found to be larger, especially, at the lower locations of the cross section. It is suggested that the responses can be managed by limiting the excitation of pendulum modes or providing special damping devices in practical engineering.

Design, simulation, and additive manufacturing performance of three lightweight FBG acceleration sensors

Low-weight, high-performance accelerometers are sought-after objectives in aerospace structural design. This paper presents three design schemes for lightweight FBG accelerometers: lattice-based (FBGL), reinforced (FBGR), and lattice-reinforced (FBGL-R) accelerometers. The influence of the design’s filling factor ( F d ) on the first-order frequency and sensitivity in three directions of the accelerometers is investigated. Additionally, the Additive Manufacturing (AM) performance of the designed accelerometers is explored and compared with the original model. The results demonstrate that the first-order natural frequencies of the three design models decrease linearly with increasing F d , with FBGL-R exhibiting a larger adjustable range of low-frequency response under the same mass. FBGL shows the greatest sensitivity variation with F d in all three directions, while FBGR exhibits the least sensitivity variation. Under the same mass fraction, FBGR demonstrates higher sensitivities in all three directions, with FBGL-R's performance falling between the other two designs. AM simulations indicate that the porous structures can reduce the deformation amplitude during the AM of FBG accelerometers. FBGL, FBGR, and FBGL-R exhibit approximately 7% lower deformations compared to the original sensor. The deformation distribution is similar among the four models, with larger residual deformations occurring at the outer edges of the components, while differences in deformation distribution exist within the porous regions.

Design of vibration sensors based on fibre Bragg grating type composites for earthquake detection and early warning application

Composite materials can be rapidly moulded using additive manufacturing processes due to their excellent mechanical and physical properties. Combining fibre Bragg gratings with composites results in high-performance fibre grating vibration sensors that address the limitations of electrical sensors and traditional materials. This study focused on developing a fibre optic acceleration sensor that utilizes a parabolic column made of silica gel. The sensor underwent fabrication, packaging, and calibration using a dedicated test system. Parametric calibrations and vibration detection tests were conducted to evaluate the performance of the system. The experimental results indicate that the sensor exhibits an intrinsic frequency of 70 Hz, a flat response range of 5 to 40 Hz, a linearity coefficient greater than 0.99, effective control of transverse interference, and exceptional low-frequency response, which improves the detection of vibration signals. Therefore, the sensor’s low intrinsic frequency and exceptional low-frequency response make it well-suited for detecting vibrations at low to medium frequencies.

A holistic understanding of optical properties in amorphous H-terminated Si-nanostructures: Combining TD-DFT with AIMD

Silicon, traditionally known as an indirect band gap semiconductor, unveils intriguing properties at the nanoscale, stemming from deviations from k-conservation rules within nanostructures. In our study, we scrutinized four hydrogenated Si 0D-nanostructures—Si10H16, Si14H20, Si18H24, and Si22H28—to unravel their dynamic stability under thermal fluctuations and optical characteristics. We initiated our exploration by employing the TD-DFT framework to generate and analyze the optical properties of these geometrically optimized nanostructures. Simultaneously, we conducted ab initio molecular dynamics simulations to examine the structural robustness and thermal stability of the four structures. Leveraging the Car-Parrinello molecular dynamics approach within the Quantum ESPRESSO open software suite, we observed temperature evolution and stability differences among the nanostructures at targeted temperatures 40 and 300 K. Our subsequent investigation delved into the Turbo-Lanczos time-dependent DFT method, unraveling the optical properties and excited-state dynamics of hydrogenated Si nanostructures. The results unveiled shifts towards higher energy absorption edges E0, accompanied by alterations in the permittivity tensor, complex refractive index, oscillator strength, and reflectivity. Notably, the analysis revealed an enlarged HOMO-LUMO gap, distinctive from bulk Si. Furthermore, our models predicted the elimination of phase-dependent E1/E2 optical transition peaks in the imaginary part of the dielectric function, and a gradual decrease in the low-frequency dielectric response with increased hydrogenation of the amorphous structures. These findings underscore the promising applications of hydrogenating Si nanostructures in diverse technological domains such as optoelectronics, memristors, sensors, and quantum computing. Their tunable optical properties, size-dependent behaviors, and compatibility with existing silicon-based devices make them particularly appealing for next-generation technologies.