Maximum Frequency Response Research Articles

Biomimetic Eu@HOF Photoactivated Sponge as Ultrasensitive Auditory and Olfactory Sensor for Infrasound Wave Monitoring and Bimodal Information Integration

AbstractThe combination of multisensory stimuli in the somatosensory system enables humans to understand object comprehensive characteristics and make precise judgments. However, the development of auditory–olfactory bimodal flexible biomimetic sensors (FBSs) to mimic the function of biological perception of external stimuli still presents complex challenges. Herein, an auditory–olfactory bimodal FBS (1 and 2) is fabricated based on hydrogen‐bonded organic framework (Eu@HOF‐BPTC) integrated with melamine sponge. During the auditory sensing process, 1 can monitor sound with a maximum response frequency of 400 Hz. The auditory FBS performs ultrahigh sensitivity (41335.995 cps Pa−1 cm−2), ultrahigh precision (relative standard deviation < 0.20%), ultrafast response time (20 ms), ultralow detection limit (1.1039 Hz and 0.1083 dB), and great recyclability (148 cycles), which can also real‐time monitor infrasound waves within 4–20 Hz. Based on artificial intelligence, 2 as an olfactory FBS demonstrates excellent sensitivity with a ppm‐level response limit and desirable selectivity toward four odor molecules and realizes wearable on‐site detection. The FBS also completes auditory and olfactory signals integration and interoperability by means of human–machine interaction. The bimodal auditory–olfactory FBS is highly promising for implementing bimodal interaction, simulating complex biological neural system, and promoting environmental monitoring, disaster warning and health care.

Mechanically Tough Micellar Cubic Liquid‐Crystalline Polymer Electrolytes for Electromechanical Actuators

AbstractThis study presents a novel micellar cubic ionic liquid‐crystalline polymer electrolyte, featuring an alignment‐free spherical structure with unimpeded 3D ionic pathways, aimed at enhancing the performance of an ionic electroactive polymer actuator. The development involved creating a mechanically tough and high ion‐conductive cubic polymer film through the self‐assembly of a wedge‐shaped vinyl imidazolium salt and an imidazolium ionic liquid, followed by in situ photopolymerization. The 300 µm‐thick‐trilayer films, consisting of the cubic polymer electrolyte sandwiched between poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate) (PEDOT:PSS) electrodes, exhibit remarkable capabilities. These include bearing substantial loads of 4 g with a high blocking force under a DC voltage of 2 V, achieving a high bending strain of 0.63% under a low input voltage (±2 V, 0.1 Hz), and boasting a maximum response frequency of 70 Hz. These properties position the material for potential applications in soft robots and tactile sensing devices.

A simultaneous audio and temperature sensing system based on in-line Mach–Zehnder interferometer

A system integrating audio and temperature sensing capabilities has been developed for simultaneous detection. Within this system, an in-line Mach–Zehnder interferometer (IMZI) sensor has been explored. Manufactured using the electro-discharge method, the sensor comprises a structure connecting single mode fiber (SMF) to polarization-maintaining fiber (PMF) and then back to SMF, with distinctive peanut-shaped junctions. The sensor’s sensitivity to temperature and curvature has been assessed to determine its potential for simultaneous audio and temperature detection. Within the temperature range of 15 °C–48 °C and a curvature range of 0 m−1–0.06654 m−1, the peak sensitivities observed were -0.1072 nm/°C and 63.5569 nm/m−1, respectively. Experimental verification confirmed the system’s audio performance using the proposed IMZI sensor. The system operates over a broad frequency range from 20 Hz to 20,000 Hz. The maximum frequency response and minimum detectable pressures (MDP) are 1804.92 mV/Pa and 11.74 μPa/Hz1/2 at 800 Hz, respectively, indicating notable acoustic sensitivity. Based on both theoretical analyses and empirical methodologies, the system successfully achieves simultaneous audio and temperature detections. This is accomplished by processing the detected data of curvature and temperature variations via high-speed sampling and dual-wavelength demodulation. Notably, this approach addresses and overcomes the sensitivity reduction experienced by acoustic sensors based on interferometers due to temperature-induced Q point drifts.

Non-linear vibration and parametric optimization of sandwich composite curved shell panels with graphene reinforced skins and auxetic honeycomb core

This study aims to investigate the non-linear free vibration behavior of composite sandwich panels composed of Graphene-reinforced composite (GRC) skins and honeycomb auxetic core. Here, modified Halpin-Tsai micromechanics and bottom-up multi-scale-based schemes are employed to compute the spatial-dependent elastic properties of Graphene nanocomposite and auxetic honeycomb core, respectively. The non-linear kinematic field is based on Kant’s higher-order shear-deformation theory and the Green strain. Using the Hamilton principle, the nonlinear governing equations are affirmed and solved further through Picard’s iteration-based 2D-isoparametric finite element approximations via Lagrangian elements. The mesh convergence and validation tests are executed to confirm the consistency and correctness of the developed model. The established sandwich model is further employed for various parametric conditions by varying the core-to-face sheet thickness, auxetic honeycomb properties, graphene volume fraction, shell configurations, temperature, and support conditions. These numerous results exemplify the non-linear frequencies at small-to-large amplitudes for the sandwich shell structures and are discussed in detail. In addition, parametric optimization is conducted using the response surface method to investigate the optimal values of auxetic honeycomb parameters, resulting in maximum frequency response. Findings confirm that, within the selected ranges of the geometric parameters of auxetic honeycomb core, higher values of the thickness of the cell rib (∼1.9 cm) and the length of the vertical cell rib (∼0.15 cm) and lower value of the core thickness (∼5 cm) yield the maximum frequency.

SEISMIC WAVE RECORDER DESIGN FOR DEVELOPMENT FOOTSTEP HUMAN DETECTION ALGORITHMS

The article shoving the results of development seismic signal recorder for purpose of registration human footstep seismic signals. Design of recorder was adopted for collection seismic signals and store it on PC, for next seismic signal processing and creation signal detection and classification algorithms.
 The article provides an overview of the types of seismic waves, their classification is given. The conditions for the propagation of seismic waves are determined, and the features of Rayleigh waves are clarified. The design structure of the seismic sensor has been developed. The specifics of the functioning of the seismic sensor are described, the place and conditions of power supply and placement of the external interface are recognized. The specifics of using the sensor of an electromechanical transducer - geophone and the features of measurements using a stationary earth are described. It is shown that the development of a seismic signal sensor circuit implies the placement of input amplifiers in its structure. The main amplitude-frequency and phase-frequency characteristics of the geophone are presented. Geophone equivalent circuit, amplifier circuit, low-pass filter circuit are presented. Illustrations of types of seismograms are given, recommendations on the features of digital signal processing are given. The order of seismic signal processing is connected with its transmission from the sensor through the amplifying stage, passing through a low-pass filter in order to minimize noise and interference. The next step is to send a signal to the ADC. From the presented graphs of sensitivity and phase shift of the geophone, it follows that special attention should be paid to the curve corresponding to the sensor with an open output. This configuration of the sensor is optimal in the context of the formation of the maximum equal frequency response.
 As papers result was proposed structural and schematic design for all main recorders blocks and software features that required for properly using recorder. Tests in real conditions on test sites have shown the correctness of the choice of schemes of technical solutions for the task of registering seismic waves.

Optimal Design and Sensitivity Analysis of the Dynamic Vibration Absorber With Amplifying Mechanism

Abstract This work optimizes a dynamic vibration absorber (DVA) model equipped with an additional amplifying mechanism using the H∞ optimization criterion, which aims to minimize the maximum frequency response amplitude of the primary structure. This optimization problem is widely investigated using the fixed-point method, which, however, works only when the primary structure is undamped and gives approximate solutions at best. Instead, we seek the exact solutions, and a resultant-based optimization scheme is accordingly proposed, which allows handling purely univariate polynomial equations in the solving procedure to guarantee the convergence and global optimum conditions. Consequently, exactly numerical and closed-form optimal DVA parameters are obtained when the primary structure is damped and undamped, respectively. Furthermore, we are also interested in the effect of the amplifying mechanism on vibration suppression, showing that it functions as a convenient equivalent mass ratio regulator to benefit the DVA performance. Finally, the presented sensitivity analysis reveals the effect of the small variations of the DVA stiffness and damping on the vibration suppression performance and the role of the amplifying mechanism in balancing such two components’ uncertainties. This work generalizes the existing exact H∞ optimization methods and provides a guideline for the enhanced DVA design using the amplifying mechanism.

Modelling and vibration control of magnetorheological-based polishing tool for robotic polishing process

The instability of the polishing force in the robot polishing process causes vibration of the polishing tool and degrades surface quality. Controlling vibration is essential for enhancing machining quality during high-precision polishing. This paper presents a magnetorheological (MR)-based polishing tool and vibration control method for improving the stability and reducing the vibration during machining. Firstly, a polishing end-effector with MR-based damper and magnetic spring mechanism is designed, the damping and stiffness model are built, the vibration dynamic model is established, and the vibration characteristics are theoretically analyzed. Multi-objective optimization is carried out to minimize the maximum frequency response value of polishing system. Then, a disturbance observer is designed to estimate the nonlinear cutting force and the stability is proved. To maintain normal contact force and reduce polishing tool vibration, a vibration controller based on polishing force with gravity compensation is proposed. The measured vibration amplitude and estimated cutting force are used as feedback in the controller to maintain the desired contact force. Finally, the polishing experiments are carried out to verify the feasibility of proposed strategy. The results show that the proposed method suppress the fluctuation of the polishing force and reduce vibration, the maximum vibration amplitude is reduced by 45% and the surface roughness is improved up 57.9%.

Broad nonlinearity in reticular lamina vibrations requires compliant organ of Corti structures

In the mammalian cochlea, each longitudinal position of the basilar membrane (BM) has a nonlinear vibratory response in a limited frequency range around the location-dependent frequency of maximum response, known as the best frequency (BF). This nonlinear response arises from the electromechanical feedback from outer hair cells (OHCs). However, recent in vivo measurements have demonstrated that the mechanical response of other organ of Corti (OoC) structures, such as the reticular lamina (RL), and the electrical response of OHCs (measured in the local cochlear microphonic [LCM]) are nonlinear even at frequencies significantly below BF. In this work, a physiologically motivated model of the gerbil cochlea is used to demonstrate that the source of this discrepancy between the frequency range of the BM, RL, and LCM nonlinearities is greater compliance in the structures at the top of the OHCs. The predicted responses of the BM, RL, and LCM to pure tone and two-tone stimuli are shown to be in line with experimental evidence. Simulations then demonstrate that the sub-BF nonlinearity in the RL requires the structures at the top of the OHCs to be significantly more compliant than the BM. This same condition is also necessary for “optimal” gain near BF, i.e., high amplification that is in line with the experiment. This demonstrates that the conditions for OHCs to operate optimally at BF inevitably yield nonlinearity of the RL response over a broad frequency range.

Design of intelligent robots for tourism management service based on green computing.

The modular intelligent robot platform has important application prospects in the field of tourism management services. Based on the intelligent robot in the scenic area, this paper constructs a partial differential analysis system for tourism management services, and adopts the modular design method to complete the hardware design of the intelligent robot system. Through system analysis, the whole system is divided into 5 major modules, including core control module, power supply module, motor control module, sensor measurement module, wireless sensor network module, to solve the problem of quantification of tourism management services. In the simulation process, the hardware development of wireless sensor network node is carried out based on MSP430F169 microcontroller and CC2420 radio frequency wireless communication chip, and the corresponding physical layer and MAC (Media Access Control) layer data definition and data definition of IEEE802.15.4 protocol are completed for software implementation, and data transmission and networking verification. The experimental results show that the encoder resolution is 1024P/R, the power supply voltage is DC5V5%, and the maximum response frequency is 100 kHz. The algorithm designed by MATLAB software can avoid the existing shortcomings and meet the real-time requirements of the system, which significantly improves the sensitivity and robustness of the intelligent robot.

A low-frequency vibration acceleration sensor based on a long-period fiber grating and a double-clamped beam

We have designed, fabricated and characterized a low-frequency vibration acceleration sensor. The sensor consists of a double-clamped beam and a long-period fiber grating (LPFG) that inscribed in a single mode fiber (SMF) by femtosecond laser. The LPFG was glued tightly to the beam top surface. Its transmission spectrum changes with beam bending, enabling vibration acceleration measurements. The experimental results display that the sensor has an accurate and steady frequency response over the frequency range of 1.5 ∼ 10 Hz with a maximum frequency response error of 4.4 %. The maximum measurable acceleration is 0.3 g, and the maximum acceleration sensitivity is 2.8 mW/g with a linearity greater than 99.6 %. The temperature drift of the sensor is less than 0.001 g/℃. The sensor has good immunity to electromagnetic interference and reliability.

The influence of inter-bubble spacing on the resonance response of ultrasound contrast agent microbubbles

Ultrasound-driven microbubbles, typically between 1 and 8 µm in diameter, are resonant scatterers that are employed as diagnostic contrast agents and emerging as potentiators of targeted therapies. Microbubbles are administered in populations whereby their radial dynamics – key to their effectiveness - are greatly affected by intrinsic (e.g. bubble size) and extrinsic (e.g. boundaries) factors. In this work, we aim to understand how two neighbouring microbubbles influence each other. We developed a finite element model of a system of two individual phospholipid-encapsulated microbubbles vibrating in proximity to each other to study the effect of inter-bubble distance on microbubble radial resonance response. For the case of two equal-sized and identical bubbles, each bubble exhibits a decrease between 7 and 10% in the frequency of maximum response (fMR) and an increase in amplitude of maximum response (AMR) by 9–11% as compared to its isolated response in free-space, depending on the bubble size examined. For a system of two unequal-sized microbubbles, the large bubble shows no significant change, however the smaller microbubble shows an increase in fMR by 7–11% and a significant decrease in AMR by 38–52%. Furthermore, in very close proximity the small bubble shows a secondary off-resonance peak at the corresponding fMR of its larger companion microbubble. Our work suggests that frequency-dependent microbubble response is greatly affected by the presence of another bubble, which has implications in both imaging and therapy applications. Furthermore, our work suggests a mechanism by which nanobubbles show significant off-resonance vibrations in the clinical frequency range, a behaviour that has been observed experimentally but heretofore unexplained.

Distributed multiple vibrations detection with high frequency response assisted by dual NLL sources

Distributed multiple vibrations detection with high frequency response is still a challenging task in distributed optical fiber vibration sensors. In terms of optical interferometer based vibration sensors, the location information can not be directly demodulated. Moreover, the detectable frequency response in the optical reflectometer based vibration sensors is limited by the repetition frequency of the modulated optical pulse. In this paper, an integrated vibration sensing scheme based on two dual narrow line-width laser (NLL) sources with different wavelengths has been theoretically proposed and experimentally demonstrated. In the scheme, one NLL source is used for constructing the phase sensitive optical time domain reflectometry (Φ-OTDR), and the other one is used to build the Michelson interferometer. These two vibration sensors are integrated by using a dense wavelength division multiplexer. Based on the sensing mechanism of the integrated vibration sensor, the multiple simultaneous vibration points can be located by the Φ-OTDR sensing part, meanwhile its corresponding frequencies information can be fully acquired by the Michelson part. Experiments on detection of the piezolelectric transducer (PZT) show that a spatial resolution of ∼20 m is achieved in a 4.95 km sensing fiber link based on the width of the modulated optical pulse in Φ-OTDR part was set as 200 ns. And a maximum frequency response can reach 45 kHz restricted by the vibration source of the PZT. Compared to conventional vibration structure, the proposed vibration sensing scheme can offer a series of unique advantages, such as simple signal demodulation process, high signal to noise ratio of the demodulated frequency spectrum, no high order harmonics in the frequency spectrum, no dead zone in the detectable frequency range and it can be achieved with a common sensing fiber.

Research on robust control of continuous rotary electro-hydraulic servo motor based on AdaBoost prediction

A robust control strategy based on Adaboost prediction was proposed for the effects of dynamic uncertainty, parameter perturbation and nonlinear factors such as friction and leakage on the robustness and low-speed performance of the electro-hydraulic servo system. Based on the establishment of the Pol-Ind friction model, according to the mathematical model of the continuous rotary electro-hydraulic servo motor, the structural uncertainty model of the system under parameter perturbation and external perturbation and the generalized state equation of the system are established. The robust controller is designed according to the [Formula: see text] control theory. The system feedback mechanism is designed by using the AdaBoost based on the RBF neural network algorithm. The real-time input and output of the system are used as the training sample set for repeated training, and the multiple weak neural network predictors obtained by training are used to form a strong predictor to calculate the forecast output and error of the electro-hydraulic servo system, and the robust controller was used for real-time control. Simulation and experiment show that: compared with the wavelet neural network control, the robust controller based on AdaBoost prediction has a good tracking performance to the slope signal with an input signal of 0.001°/s, and has a high response speed to sinusoidal signal. Under the condition of satisfying the requirement of double 10 index, the maximum response frequency reaches 15 Hz. It can effectively improve the low-speed performance and anti-interference ability of the electro-hydraulic servo system, greatly improve the robustness of the system and expand the frequency band of the system.

LPI radar target detection performance optimization based on joint cognitive frequency transmission and power allocation

In the Low Probability of Intercept (LPI) radar system, in order to optimize the radar target detection performance, the energy consumption should be reduced while improving the target detection performance. Based on the Hidden Markov Model (HMM), this paper proposes an optimization algorithm for target detection performance joint cognitive frequency transmission and power allocation combined with the target Radar Cross Section (RCS) frequency response function prediction. The algorithm uses the target RCS's characteristics with different frequency response functions at different frequencies. The radar transmits a set of broadband pulse signals with different frequencies at the current time to irradiate the target and obtain the echo. The passive receiving system processes the echo to obtain the target RCS frequency response measurement value, and determines it as a priori information. The RCS frequency response function of the target at the subsequent time is predicted by the prior information and HMM, and the complete RCS prediction information of the target is obtained. Finally, using the radar equation, the radar transmitting power is calculated through the maximum frequency response function in the predicted values at different times and its corresponding transmitting frequency. The optimized information is then transmitted to the detection radar to complete the joint cognitive frequency transmission and power allocation. The simulation results show that the method used in this paper can lead to more accurate prediction information than the traditional algorithm, efficiently reduce the target detection transmitting power, and improve the radar target detection and LPI performance, which has a high engineering application value.

Donbas geoelectrical structure

The Donbas was formed as the result of Late Devonian rifting of the East European craton. During the Carboniferous, the subsidence of the basin and sedimentation were at their maximum, and a 15-kilometer stratum of Carboniferous deposits formed in the Donbas. The total thickness of the deposits reaches more than 20 km. The next important event was folding, which occurred in the Late Triassic — Early Jurassic and Late Cretaceous — Early Tertiary. The inversion lifted the upper part of the folded Donbas and subsequent erosion exposed the Carboniferous coal-bearing strata on the surface of the earth. Deep electrical conductivity was studied by the methods of magnetovariational profiling (MVP) and magnetotelluric sounding (MTS). The first large survey (13 long-period MTS sites and 32 MTS points) was carried out in 1986; in 1988 another 30 MTS were performed. In 2012-2013, a profile of 15 MVP-MTS sites was made with modern instruments that allow obtaining more accurate results. The data interpretation yields the following conclusions. The intense Donbass electrical conductivity anomaly (DAE) runs along the main anticline of the folded Donbass. In the northwest, it continues in the DDD, in the southeast — on the Karpinsky swell. DAE parameters obtained by the MVP method: Based on the frequency response of the anomalous field, the total longitudinal conductance G = (8±2)×108S×m was estimated. Profile graphs of the anomalous field of geomagnetic variations give an estimate of the maximum possible depth of the anomalous currents center hmax.c.curr, which depends on the variations period. For DAE at the maximum frequency response Т0≈3600 s, it turns out to be equal to hmax.c.curr=18±2 km. The upper edge of the anomaly is estimated from MTS data. Most of the available 70 MTS ρк curves begin at periods of 0.1—1 s from approximately the same level of 15 Ohm·m±half an order of magnitude. This means that in the Donbass, the rocks of the upper approximately half-kilometer layer have, as a rule, electrical resistivity in the range of 5—50 Ohm·m. Deeper, the resistivity can increase to hundreds and thousands of Ohm·m or decrease to units or fractions of Ohm·m. An analysis of the MTS by area showed that objects of low resistance (LRO) are located in two conductive bands, the upper edge of which varies from 0.3 to 5 km. The bands are parallel to the DAE axis and can be considered as some part of the anomaly. A very large value of G leads to the assumption that the anomalous body extends to a considerable depth. When compared with the data of other geophysical methods, it turned out that the DAE spatially coincides with an intense (up to 90 mW/m2) linear anomaly of the deep heat flow. This fact suggests that the nature of the DAE lower part can be a partial melting of fluid-enriched heated local rocks or intrusion of mantle magma. The obtained geoelectric results support the idea of the modern tectonic activation in Donbas.

Investigating the resonance response of a system of two ultrasound-driven lipid encapsulated microbubbles

Ultrasound-stimulated microbubbles are clinical imaging agents and being developed for therapeutic applications. Here, we aim to understand the behaviour of two individual phospholipid-encapsulated microbubbles in close proximity to each other, typically the case given clinical doses. We developed a finite element model to study the radial resonance response of each microbubble within a two-microbubble system from 1–8 MHz with bubble diameters ranging from 2 to 4 μm, bubble center-to-center distances h = 8–24 μm, and peak-negative pressures of 30–45 kPa. For two identical microbubbles, our results show the frequency of maximum response (fMR) decreases (7%–10%) and the amplitude of maximum response (AMR) increases (9%–11%) as the microbubbles approach one another. For a two-bubble system of different microbubble sizes, the larger microbubble shows no change in fMR and a slight shift of AMR (2–3%). However, the smaller microbubble exhibits an increase in fMR (7–11%) and a significant decrease of AMR (38–52%). Furthermore, when in very close proximity (h = 8 μm), smaller bubbles exhibit a secondary resonance peak corresponding to the fMR of the larger bubble with amplitudes comparable to its primary resonance peak. Our work suggests that microbubble resonance behaviour is greatly affected by the presence of nearby bubbles, which has implications in imaging and therapy.

External-cavity laser diode using acousto-optic deflector as tunable grating.

In this study, a novel, to the best of our knowledge, external-cavity laser diode (ECLD) without a diffraction grating is proposed and demonstrated. In the proposed configuration, an acousto-optic deflector (AOD) acts not only as a deflector but also as a diffraction grating. Thus, the AOD functions as a wavelength-selective device, which helps improve the overall performance of the ECLD. In fact, the proposed configuration realizes a wide range of wavelength scanning with a simple configuration, highly efficient optical feedback, and a steady optical resonator with a constant cavity length. We confirm that the wavelengths scanned with the proposed ECLD agree well with theoretical calculations. The scanning range and maximum frequency response reached approximately 60 nm and 50 kHz, respectively. Moreover, reproducible measurements of the three-dimensional thickness distribution of a thin glass plate indicates that the proposed ECLD can be used for optical coherence tomography imaging systems.

Acousto-Optic Cells with Phased-Array Transducers and Their Application in Systems of Optical Information Processing.

This paper presents the results of theoretical and experimental studies of anisotropic acousto-optic interaction in a spatially periodical acoustic field created by a phased-array transducer with antiphase excitation of adjacent sections. In this case, contrary to the nonsectioned transducer, light diffraction is absent when the optical beam falls on the phased-array cell at the Bragg angle. However, the diffraction takes place at some other angles (called “optimal” here), which are situated on the opposite sides to the Bragg angle. Our calculations show that the diffraction efficiency can reach 100% at these optimal angles in spite of a noticeable acousto-optic phase mismatch. This kind of acousto-optic interaction possesses a number of interesting regularities which can be useful for designing acousto-optic devices of a new type. Our experiments were performed with a paratellurite (TeO2) cell in which a shear acoustic mode was excited at a 9° angle to the crystal plane (001). The piezoelectric transducer had to nine antiphase sections. The efficiency of electric to acoustic power conversion was 99% at the maximum frequency response, and the ultrasound excitation band extended from 70 to 160 MHz. The experiments have confirmed basic results of the theoretical analysis.

Investigation of the frequency properties of a standard linear body

It is known that the Кelvin-Voigt model does not describe stress relaxation, which is observed along with elastic properties in many polymers and biomaterials. In this regard, the standard linear body model is used to describe the properties of these materials. Studies of its properties were mainly limited to the study of its reaction to an instantaneously applied load, as well as to the determination of the time and nature of stress relaxation. Аt the same time, the frequency properties of the standard linear body remained unexplored. In this regard, an analysis of its frequency properties was carried out, which made it possible to study its behavior under vibration exposure. Оn the basis of the equation of motion, the amplitude-frequency response (АFC) was constructed, and its peculiarity was revealed, which consists in the fact that an increase in the damping coefficient leads to a decrease in the maximum value of the АFC only to a certain value greater than one. А further increase in the damping coefficient leads to an increase in the maximum frequency response up to infinity at a frequency that should also be considered resonant. Thus, the frequency response of a standard linear body always has a maximum. The subsequent increase in the damping coefficient leads to the tendency of the maximum frequency response to zero at infinity.

Anti-seismic Performance Comparison of Response Spectrum Analysis and Time History Analysis Based on Computer Big Data

This paper introduces the methods and principles of response spectrum analysis and time history analysis of seismic performance of structures based on computer big data. In order to discuss the common ground and the consistency of the calculated results between the two methods, the response spectrum analysis, time history analysis based on seismic level 8 synthetic seismic wave and seismic test were carried out on an IDC cabinet structure. The results showed that both the response spectrum method and the time-history analysis method reflect the effects of ground motion characteristics and structural dynamic characteristics on the seismic response of the structure in the seismic performance calculation, and the simulation results of the two methods were consistent in the response maximum value and response frequency.