Transient Response Research Articles

A high current efficiency rail-to-rail operational amplifier

ABSTRACT This paper proposes a new single stage high current efficiency rail to rail amplifier (HCE-RTR). Due to the combination of a new constant transconductance control circuit and local common mode feedback (LCMFB) technique, the proposed rail to rail amplifier not only achieves improvements in unity-gain bandwidth (GBW) and slew rate (SR), but also ensures input stage transconductance constancy within the rail to rail voltage range. Based on the SMIC 180 nm process, the post-layout simulation results show that the proposed amplifier achieves rail-to-rail input/output. The simulated open loop AC response shows the DC gain, GBW, and PM are 66.2 dB, 8.2 MHz, and 60.97 o , respectively. When the driving load capacitance is 70 pF, the transient response simulation results show that the proposed amplifier achieves 0.039 µs average 1% settling time, and about 5.73 V/µs average slew rate. Note that under the condition of 1.8 V power supply, the power consumption is only 122.4 µW, proving the proposed amplifier can achieve high current efficiency while maintaining stability.

Practical Method for Achieving Single-Photon Femtosecond Time-Resolved Spectroscopy: Transient Stimulated Emission.

Recent advances in single-photon femtosecond spectroscopy have highlighted the power of entangled photons in probing the properties of materials, previously inaccessible through semiclassical spectroscopic approaches. In this study, we theoretically propose a new single-photon-based femtosecond time-resolved spectroscopy technique termed single-photon transient stimulated emission (SP-TSE). SP-TSE not only enables the selective investigation of singly excited superposition states but also harnesses the quantum mechanical nature of photons for the efficient data acquisition of transient responses, thereby supporting the feasibility of experimental realization of SP-TSE. The key aspect of SP-TSE is the selective detection of two-photon states produced through stimulated emission using coincidence counting techniques. Our theoretical framework, supported by numerical simulations, demonstrates the efficacy in capturing the pure decoherence dynamics of a model molecular cavity, highlighting its potential to reveal quantum mechanical properties that are difficult to observe with semiclassical femtosecond time-resolved experiments.

The microtubule targeting agent ST-401 triggers cell death in interphase and prevents the formation of polyploid giant cancer cells

Microtubule targeting agents (MTAs) are commonly prescribed to treat cancers and predominantly kill cancer cells in mitosis. Significantly, some MTA-treated cancer cells escape death in mitosis, exit mitosis and become malignant polyploid giant cancer cells (PGCC). Considering the low number of cancer cells undergoing mitosis in tumor tissues, killing them in interphase may represent a favored antitumor approach. We discovered that ST-401, a mild inhibitor of microtubule (MT) assembly, preferentially kills cancer cells in interphase as opposed to mitosis, a cell death mechanism that avoids the development of PGCC. Single cell RNA sequencing identified mRNA transcripts regulated by ST-401, including mRNAs involved in ribosome and mitochondrial functions. Accordingly, ST-401 induces a transient integrated stress response, reduces energy metabolism, and promotes mitochondria fission. This cell response may underly death in interphase and avoid the development of PGCC. Considering that ST-401 is a brain-penetrant MTA, we validated these results in glioblastoma cell lines and found that ST-401 also reduces energy metabolism and promotes mitochondria fission in GBM sensitive lines. Thus, brain-penetrant mild inhibitors of MT assembly, such as ST-401, that induce death in interphase through a previously unanticipated antitumor mechanism represent a potentially transformative new class of therapeutics for the treatment of GBM.Graphical

Analysis, Simulation, and Experiments of Dynamics and Control of a Hydrostatic Wind Turbine Under Partial Load

Abstract Kω2 control, also called torque control, is a popular method for maximizing wind turbine power. For hydrostatic wind turbines, torque control becomes pressure control with pc=K'ω2 because pressure is proportional to torque. Inverse Kω2 control is an alternative approach using rotor speed control with pc=(p/K')1/2. This work analyzes the dynamics of hydrostatic wind turbines using forward and inverse Kω2 control with P-, PD-, PI-, and PID-control for feedback. Dimensionless, linearized models are used. Analysis shows that the mechanical rotor dynamics are much slower than the hydrostatic transmission dynamics and that frictional and leakage losses are negligible. Linear perturbation of the nonlinear model reveals that the closed-loop control is not in Evan's form, so that closed-loop poles and zeros both vary with the loop gain. Pole and zero root locus analysis shows how systems responses change with controller gains. Both control approaches require derivative controller action to sufficiently dampen their responses; both are also fundamentally limited in speed of response by a slow stable pole regardless of controller loop gains. Nonlinear system simulation shows that both control approaches track the maximum power point with nearly identical transient behavior and have nearly identical power losses when using suboptimal values of the control law gain, K. Pressure control has a gain margin of infinity and a phase margin of 99.3 degrees, while speed control has a gain margin of 22.4 dB and a phase margin of 73.8 degrees showing that pressure control is more robust than speed control. Experiments using the power regenerative hydrostatic test stand at the University of Minnesota show that the control approaches have different transient responses but capture comparable power under steady and turbulent conditions.

Transient response to high‐dose niacin therapy in a patient with NAXE deficiency

AbstractBackgroundNAXE‐encephalopathy or early‐onset progressive encephalopathy with brain edema and/or leukoencephalopathy‐1 (PEBEL‐1) and NAXD‐encephalopathy (PEBEL‐2) have been described recently as mitochondrial disorders causing psychomotor regression, hypotonia, ataxia, quadriparesis, ophthalmoparesis, respiratory insufficiency, encephalopathy, and seizures with the onset being usually within the first three years of life. It usually leads to rapid disease progression and death in early childhood. Anecdotal reports suggest that niacin, through its role in nicotinamide adenine dinucleotinde (NAD) de novo synthesis, corrects biochemical derangement, and slows down disease progression. Reports so far have supported this observation.MethodsWe describe a patient with a confirmed PEBEL‐1 diagnosis and report his clinical response to niacin therapy. Moreover, we systematically searched the literature for PEBEL‐1 and PEBEL‐2 patients treated with niacin and details about response to treatment and clinical data were reviewed. Furthermore, we are describing off‐label use of a COX2 inhibitor to treat niacin‐related urticaria in NAXE‐encephalopathy.ResultsSo far, seven patients with PEBEL‐1 and PEBEL‐2 treated with niacin were reported, and all patients showed a good response for therapy or stabilization of symptoms. We report a patient exhibiting PEBEL‐1 with an unfavorable outcome despite showing initial stabilization and receiving the highest dose of niacin reported to date. Niacin therapy failed to halt disease progression or attain stabilization of the disease in this patient.ConclusionDespite previous positive results for niacin supplementation in patients with PEBEL‐1 and PEBEL‐2, this is the first report of a patient with PEBEL‐1 who deteriorated to fatal outcome despite being started on the highest dose of niacin therapy reported to date.

Modelling lung infection with Klebsiella pneumoniae after murine traumatic brain injury

Pneumonia is a common comorbidity in patients with severe traumatic brain injury (TBI), and is associated with increased morbidity and mortality. In this study, we established a model of intratracheal Klebsiella pneumoniae administration in young adult male and female mice, at 4 days following an experimental TBI, to investigate how K. pneumoniae infection influences acute post-TBI outcomes. A dose-response curve determined the optimal dose of K. pneumoniae for inoculation (1 x 10^6 colony forming units), and administration at 4 days post-TBI resulted in transient body weight loss and sickness behaviors (hypoactivity and acute dyspnea). K. pneumoniae infection led to an increase in pro-inflammatory cytokines in serum and bronchoalveolar lavage fluid at 24 h post-infection, in both TBI and sham (uninjured) mice. By 7 days, when myeloperoxidase + neutrophil numbers had returned to baseline in all groups, lung histopathology was observed with an increase in airspace size in TBI + K. pneumoniae mice compared to TBI + vehicle mice. In the brain, increased neuroinflammatory gene expression was observed acutely in response to TBI, with an exacerbated increase in Ccl2 and Hmox1 in TBI + K. pneumoniae mice compared to either TBI or K. pneumoniae alone. However, the presence of neuroinflammatory immune cells in the injured brain, and the extent of damage to cortical and hippocampal brain tissue, was comparable between K. pneumoniae and vehicle-treated mice by 7 days. Examination of the fecal microbiome across a time course did not reveal any pronounced effects of either injury or K. pneumoniae on bacterial diversity or abundance. Together, these findings demonstrate that K. pneumoniae lung infection after TBI induces an acute and transient inflammatory response, primarily localized to the lungs with some systemic effects. However, this infection had minimal impact on secondary injury processes in the brain following TBI. Future studies are needed to evaluate the potential longer-term consequences of this dual-hit insult.

Electrophysiological correlates of sustained conscious perception

Previous research on the neural correlates of consciousness (NCC) in visual perception revealed an early event-related potential (ERP), the visual awareness negativity (VAN), to be associated with stimulus awareness. However, due to the use of brief stimulus presentations in previous studies, it remains unclear whether awareness-related negativities represent a transient onset-related response or correspond to the duration of a conscious percept. Studies are required that allow prolonged stimulus presentation under aware and unaware conditions. The present ERP study aimed to tackle this challenge by using a novel stimulation design. Male and female human participants (n = 62) performed a visual task while task-irrelevant line stimuli were presented in the background for either 500 or 1000 ms. The line stimuli sometimes contained a face, which needed so-called visual one-shot learning to be seen. Half of the participants were informed about the presence of the face, resulting in faces being perceived by the informed but not by the uninformed participants. Comparing ERPs between the informed and uninformed group revealed an enhanced negativity over occipitotemporal electrodes that persisted for the entire duration of stimulus presentation. Our results suggest that sustained visual awareness negativities (SVAN) are associated with the duration of stimulus presentation.

Improving Copper Active Site Speciation on Cu-Ce/SSZ-13 for Ammonia Oxidation via Si/Al Ratio Modulation.

Catalytic oxidation is a promising purification technique for ammonia (NH3) emission. However, high ignition temperatures and NOx peroxide generation limit its effectiveness due to a lack of active sites. Herein, the effects of Si/Al ratio (SAR) modulation on the speciation of copper active sites and the reaction mechanism at different acidic sites were investigated by loading CuO-CeO2 onto SSZ-13 with different SARs (Cu-Ce/SAR15, 20, and 30). Among them, Cu-Ce/SAR20 exhibits the lowest induction temperature (T20 = 180 °C) and the highest nitrogen selectivity (above 95%), attributing to a higher number of Cu2+ exchange sites. In situ IR spectroscopy and isotopic (18O2) transient response experiments indicate that more active Cu2+ in Cu-Ce/SAR20 provides sufficient Lewis acidic sites for NH3 adsorption and favors the stability of Si-OH-Al structures (Brønsted acid sites). NH3 adsorbed at Lewis acidic sites tends to form peroxide byproducts (NOx), while the NH4+ adsorbed at Brønsted acidic sites generates the key intermediate NH4NO2, which decomposes to N2 at high temperatures, thus enhancing nitrogen selectivity. The whole process mainly follows the Mars-van Krevelen (M-K) mechanism, with the Langmuir-Hinshelwood (L-H) mechanism playing a supporting role. Z2Cu2+ coordinates with adjacent Al atoms within the six-membered ring (6MR) and undergoes a slight deformation at high temperatures, facilitating the migration of the lattice oxygen. SAR plays a crucial role in local environmental speciation of reactive Cu2+, where the sufficient isolated Al provided in SAR20 pulls Cu2+ into the eight-membered ring (8MR), allowing it to come into contact with NH3 more readily.

A decision-making approach on control techniques for an inverted pendulum based on, neuro-fuzzy, indirect adaptive and PID controllers

The operation of an inverted pendulum and its respective type of control are affected by the change of the values of its internal parameters. Changes with high uncertainty result in responses with undesirable outputs. In this work, a comparison is presented for the control of an inverted pendulum to determine the operation and characteristics of three types of control systems: Neuro-Fuzzy Control (NFC), Indirect Adaptive Control (IAC) and a Proportional Integral Derivative control (PID). The study considers several indices such as stabilization time, rise time, mean square error, overshoots, convergence, computational load, error, mathematical requirements, and performance indices for control systems. To demonstrate its operation, the controls are implemented in hardware, one for the NFC and another for the IAC under an Arduino UNO platform. The results indicate that the NFC and IAC controls do not generate a transient or impulse response, only a small delay and the rise and stabilization time are minimal. While PID presents a transient response and overshoot, as well as a stabilization time to reach the steady state response.

Analysis of Transient Thermoacoustic Characteristics and Performance in Carbon Nanotube Sponge Underwater Transducers

Recent advancements in marine technology have highlighted the urgent need for enhanced underwater acoustic applications, from sonar detection to communication and noise cancellation, driving the pursuit of innovative transducer technologies. In this paper, a new underwater thermoacoustic (TA) transducer made from carbon nanotube (CNT) sponge is designed to achieve wide bandwidth, high energy conversion efficiency, simple structure, good transient response, and stable sound response, utilizing the TA effect through electro-thermal modulation. The transducer has potential application in underwater acoustic communication. An electro-thermal-acoustic coupled simulation for the open model, sandwich model, and encapsulated model is presented to analyze the transient behaviors of CNT sponge TA transducers in liquid environments. The effects of key design parameters on the acoustic performances of both systems are revealed. The results demonstrate that a short pulse excitation with a low duty cycle could greatly improve the heat dissipation of the encapsulated transducer, especially when the thermoacoustic response time becomes comparable to thermal relaxation time.

High responsivity VIS-NIR photodetector based on (PEA)2PbI4/P3HT Heterojunction

Abstract Two-dimensional (2D) Ruddlesden-Popper (RP) perovskite is an ideal platform for building high-performance photodetectors due to its unique structure, excellent stability, and tunable bandgap. However, 2D perovskite heterojunction photodetectors are still less reported. In this work, the photodetector based on (PEA)2PbI4/P3HT heterojunction was prepared by the liquid-phase solution method under air conditions, which showed a responsivity (R) of 8.38 A/W and a specific detectivity (D*) of 6.53 × 1011Jones under 808 nm light. In addition, the device has a transient response time of 79.57 µs/484 µs and a high stability performance that maintains more than 95% of the photocurrent under continuous cycling tests and shows good cyclic stability after 30 days without encapsulation. This work provides a promising strategy for extending 2D perovskite photodetectors in the VIS to NIR spectral range.

Low-donor content approach to achieve sensitive narrowband organic photodetectors

Narrowband near-infrared (NIR) detectors are key components for various modern biomedical, agricultural, astronomical sensing as well as monitoring applications. Typically, a narrowband organic photodetector (OPD) requires thick junctions or additional optical elements, which are either tedious or cost-ineffective. Here, we adopt the low-donor content strategy in our thin-film device to realize narrowband spectral features. The much-mitigated aggregation drastically improves shunt resistance and dark current while maintaining decent photocurrent. Upon further dilution, a thinner electron transporting layer can effectively shorten the transient response to reach fast speed. n-i-p and p-i-n device configurations are also compared, which exhibits drastic changes for low-donor content OPDs. The 5 wt% D:A thin-film bulk-heterojunction OPD presents an external quantum efficiency of 49.3% at 770 nm with zero bias, and a high thermal-noise calculated specific detectivity (D*) of 1.0 × 1013 Jones (7.1 × 1012 Jones based on noise spectral density) at 0 V. Such narrowband OPD also shows a fast NIR response of 530 ns/840 ns (rise/fall) when operated at 10 kHz. The results reveal the potential for low-donor-content blend in realizing narrowband photodetection.

Experimental investigation on the transient vascular thermal response to laser irradiation by a high-speed infrared thermal camera

Based on the photothermal effect, laser can be used to treat vascular diseases (VD) in clinic of dermatology and ophthalmology. Transient vascular thermal response to laser irradiation during millisecond laser pulse is the key phenomenon in treatment process, which has not been carefully investigated before. In this study, target blood vessels in dorsal skin chamber (DSC) animal model were irradiated by a pulsed 532 nm diode laser and a 1064 nm Nd:YAG laser. The directed thermal responses (temperature variation) were recorded by a high-speed infrared thermal camera with a repetition rate of 1000 Hz. The temperature variation during and after single pulse irradiation and multipulse irradiation were investigated. The variation of blood absorption coefficient was explored based on the temperature increment in each laser pulse. The thermal properties of dorsal skin, especially the thermal diffusivity, were evaluated based on the temperature decay after each laser pulse. The interfacial heat transfer between the blood and the surroundings was also calculated based on the thermal images and compared to the correlation proposed before. The results show that the blood absorption to laser will increase by a maximum of 1.9 immediately after blood temperature exceeds threshold value, e.g., 68oC in both single pulse (pulse duration >100 ms) and multi-pulse laser irradiation. The tissue optical properties (thermal diffusivity) keep almost constant after millisecond laser heating. Also, a general correlation for interfacial heating transfer between blood and surroundings was developed, in which the influences of vessel shape and laser wavelength are incorporated. The interfacial heat transfer between blood and surrounding can be accurately quantified.

Investigation of a dexterous actuator integrated with magnetorheological bearings towards high switching frequency and fast response

Abstract Actuators are pivotal for empowering robots to execute a wide array of tasks and adapt to diverse surroundings. However, conventional actuators with low switching frequency and prolonged response time significantly comprise the adaptability of robots, restricting them to single operation condition. This paper presents a solution to this issue by introducing a magnetorheological (MR) actuator with real-time controllable damping. Compared to conventional actuators, the MR actuator boasts exceptional dexterity, featuring a significantly elevated switching frequency and swifter response time. To validate the MR actuator's remarkable dexterity, rapid commutation tests and transient response experiments were conducted. Impressively, the MR actuator achieved a stable switching frequency up to 10 Hz, surpassing that of conventional actuators (2 Hz). Moreover, it demonstrated reduced response time and heightened energy efficiency. Beyond robotics, MR actuators also find applications in areas which require improved machinery precision and production efficiency.

Elucidating the in-process interfacial friction regime and thermal responses during inertia friction welding of dissimilar superalloys

Inertia friction welding (IFW) is a robust joining technique, particularly for hybrid structures composed of similar or dissimilar alloys. The highly transient thermal responses during friction heating produce variations in heat generation and temperature distribution, which are crucial for designing and controlling the IFW process. This study establishes a finite element (FE) model of the IFW process for dissimilar superalloys and investigates the transition of the interfacial friction regime and its impact on the transient thermal responses. The in-process state variables, including the frictional stress and heat flux, along with their spatial distributions at the welding interface, are obtained through FE simulations. The predicted results indicate that the transient transition of the friction regime produces 2 C friction zones accompanied by a shear friction zone. To capture the transient evolution of the friction regime, a novel phenomenological formula is developed. This model accurately predicts the shrinkage and disappearance of the 2 C friction zones and the enhancement of the shear friction zone from the initial 0.42 R0–0.87 R0 (where R0 is the workpiece radius) to the entire interface during the IFW process. The variations in interfacial heat flux, frictional stress, and temperature caused by the transition of the friction regime are comprehensively analyzed. Our results reveal that the transition from the Coulomb friction regime to shear friction regime at the interface is beneficial for temperature homogenization at the welding interface. The FE simulation results are validated against published experimental measurements, which confirms the accuracy and reliability of the FE model.

Method to determine instantaneous transient responses in pressurized pipes from transfer functions and state space for evaluation of leak signals

This article addresses the impact of transient pressure anomalies in hydraulic systems, triggered by the opening or closing of valves or pumps, instantly disturbing the line of hydraulic gradient (LGH). This variation in pressure has significant consequences both in hydraulic and structural terms for water networks. Most of the existing techniques to detect transients in water distribution systems use asynchronous methods, generating timeless information that limits the response capacity in critical situations. Therefore, an automatic transient detection system based on the Internet of Things (IoT) is proposed, capable of identifying overpressure or underpressure pulses in soft real-time, activating alarms to facilitate decision-making. This approach helps maintain the safety of the water distribution system and prevent leaks in the network. Furthermore, a model of the transient behavior of pressure and flow is presented by linearizing the water hammer equations from the Laplace transform, thus generating a transfer function that describes the algebraic relationship between the outlet and inlet of the hydraulic system.•The transient analysis of the hydraulic system prototype underscores its high sensitivity to initial conditions, attributed to turbulence. This observation suggests the possible presence of a dynamic strange attractor related to water hammer phenomena in pressure pipes.•The methodology involving transfer functions and state-space models enables the assessment of how leaks impact the transient responses of the system, including the magnitude, duration, and frequency of disturbances generated by them.•The proposed method introduces a dynamic transfer function capable of identifying instantaneous changes over time in terms of flow and pressure.

Friend or foe: The role of stress granule in neurodegenerative disease.

Stress granules (SGs) are dynamic membraneless organelles that form in response to cellular stress. SGs are predominantly composed of RNA and RNA-binding proteins that assemble through liquid-liquid phase separation. Although the formation of SGs is considered a transient and protective response to cellular stress, their dysregulation or persistence may contribute to various neurodegenerative diseases. This review aims to provide a comprehensive overview of SG physiology and pathology. It covers the formation, composition, regulation, and functions of SGs, along with their crosstalk with other membrane-bound and membraneless organelles. Furthermore, this review discusses the dual roles of SGs as both friends and foes in neurodegenerative diseases and explores potential therapeutic approaches targeting SGs. The challenges and future perspectives in this field are also highlighted. A more profound comprehension of the intricate relationship between SGs and neurodegenerative diseases could inspire the development of innovative therapeutic interventions against these devastating diseases.

Unveiling Enhanced PEC Water Oxidation: Morphology Tuning and Interfacial Phase Change in α-Fe2O3@K-OMS-2 Branched Core-Shell Nanoarrays.

A simple fabrication method that involves two steps of hydrothermal reaction has been demonstrated for the growth of α-Fe2O3@K-OMS-2 branched core-shell nanoarrays. Different reactant concentrations in the shell-forming step led to different morphologies in the resultant composites, denoted as 0.25 OC, 0.5 OC, and 1.0 OC. Both 0.25 OC and 0.5 OC formed perfect branched core-shell structures, with 0.5 OC possessing longer branches, which were observed by SEM and TEM. The core K-OMS-2 and shell α-Fe2O3 were confirmed by grazing incidence X-ray diffraction (GIXRD), EDS mapping, and atomic alignment from high-resolution STEM images. Further investigation with high-resolution HAADF-STEM, EELS, and XPS indicated the existence of an ultrathin layer of Mn3O4 sandwiched at the interface. All composite materials offered greatly enhanced photocurrent density at 1.23 VRHE, compared to the pristine Fe2O3 photoanode (0.33 mA/cm2), and sample 0.5 OC showed the highest photocurrent density of 2.81 mA/cm2. Photoelectrochemical (PEC) performance was evaluated for the samples by conducting linear sweep voltammetry (LSV), applied bias photo-to-current efficiency (ABPE), electrochemical impedance spectroscopy (EIS), incident-photo-to-current efficiency (IPCE), transient photocurrent responses, and stability tests. The charge separation and transfer efficiencies, together with the electrochemically active surface area, were also investigated. The significant enhancement in sample 0.5 OC is ascribed to the synergetic effect brought by the longer branches in the core-shell structure, the conductive K-OMS-2 core, and the formation of the Mn3O4 thin layer formed between the core and shell.

Optimizing Photocatalytic and Supercapacitive Performance by β-Bi2O3@BiFeO3 Modification with PVDF Polymer based Nanocomposites

The PVDF (Poly-Vinyl-difloride) membrane modified with Bismuth oxide (β-Bi2O3)/Bismuth Ferrite (BiFeO3) p-n heterojunction synthesized via hydrothermal process to explore its energy storage and conversion applications. The PVDF-Bi2O3/BiFeO3 nanocomposites (NCs) prepared in this study were subjected to analysis using PXRD, FTIR, UV-Vis DRS, FE-SEM with EDX, TEM, and transient photocurrent response techniques, individually. The as-prepared materials were evaluated for their photocatalytic performance in the visible light-induced degradation of Methylene Blue (MB) and Rhodamine-B (RhB) dyes. The photocatalytic performance demonstrates degradation efficiencies of 95% for MB dye and 83% for RhB dye when utilizing the PVDF-β-Bi2O3@BiFeO3 nanocatalyst. The enhancement in the photocatalytic performance of the PVDF-Bi2O3/BiFeO3 heterojunction was a result of improved visible light absorption, suppression of photogenerated electron-hole pair recombination, accelerated separation and migration of photogenerated charges. The capacitance behavior of PVDF-β-Bi2O3@BiFeO3 is significantly higher than β-Bi2O3@BiFeO3 in 3M KOH solution which has specific capacitance of 300Fg-1at 1Ag-1 of current density and fabricated a symmetric device has10.08Whkg-1 and 999.39Wkg-1 specific energy and specific power at 0.5Ag-1 of current density with the 88.7% of capacitance retention and 94.12% of coulombic efficiency up to 10000 cycles.

Design and optimization of a two-degrees-of-freedom single-sided vibro-impact nonlinear energy sink for transient vibration suppression of a thin plate

To rapidly suppress the transient vibration response of a thin plate, a two-degrees-of-freedom single-sided vibro-impact nonlinear energy sink (TSSVI NES) is proposed in this paper. Based on the Kirchhoff hypothesis, the coupled equations of motion between the plate and the TSSVI NES are established. The system is modeled by the Galerkin technique and numerically solved using the fourth order Runge-Kutta method. To obtain the optimal parameters of the TSSVI NES, a particle swarm optimization method is adopted. The system response with the TSSVI NES is compared with that of the cubic nonlinear energy sink (CNES) and the single-sided vibro-impact nonlinear energy sink (SSVI NES), showing that the vibration suppression ability of the TSSVI NES is better. The mechanism of rapid response suppression of the TSSVI NES is demonstrated by way of simulations. A parametric study is also conducted to determine the effects of damping, the coefficient of restitution, mass, stiffness, and installation position of TSSVI NES on the efficacy of the vibration control device. The numerical results demonstrate that the performance of the TSSVI NES is robust to the damping, coefficient of restitution, and installation position, but sensitive to mass difference and stiffness difference. Finally, the effect of the TSSVI NES is examined when the plate is excited by seismic loads, demonstrating a good response suppression performance.