scholarly journals Acceleration Response Analysis of a Steel-wood Composite Floor System under Human-induced Vibration

2021 ◽  
pp. 60-71
Author(s):  
Dong Yujian ◽  
Cao Lilin
Keyword(s):  
Experimental Situation ◽  
Excitation Frequency ◽  
Vibration Response ◽  
Response Analysis ◽  
Wood Composite ◽  
Peak Acceleration ◽  
Acceleration Response ◽  
Jump Frequency ◽  
Structure Interaction ◽  
Floor System

To investigate the vibration response of a steel-wood composite floor system under walking and jump excitation. The ABAQUS subroutine Vdload is used to simulate the human walking and jumping process on the structure, while the human-induced excitation is equated to a combination of a Fourier-scale load model and a biomechanical model of mass, stiffness, and damping (MSD) to study the human-induced vibration response under human-structure interaction (HSI). The effects of walking and jumping excitation on the peak acceleration of the structure are also considered. The results show that the peak acceleration of the structure considering the human-structure interaction is significantly smaller than that without the human-structure interaction, and the results obtained from the numerical simulation analysis are more consistent with the experimental situation. In addition, the acceleration response of the steel-wood composite floor system under jump excitation is larger than that of walking excitation, and the peak acceleration increases with the increase of jump frequency. Then: any floor, no matter its structural configuration and material, is prone to vibrate under walking and jumpimg excitation if the excitation frequency is in resonance with one of its main frequencies. The induced vibrations affect the floor serviceability, when the induced peak acceleration exceeds the comfort requirements. The magnitude of the induced peak acceleration is the larger, the larger the acting force and the lower the vibrating floor mass and its damping.

scholarly journals Fluid-Structure Interaction Vibration Response Analysis of the Hydrocyclone Under Periodic Excitation

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 146273-146281 ◽  
Author(s):  
Sen Li ◽  
Ruoning Li ◽  
Zunce Wang ◽  
Dekui Xu ◽  
Yuejuan Yan ◽  
...  
Keyword(s):  
Fluid Structure Interaction ◽  
Vibration Response ◽  
Response Analysis ◽  
Periodic Excitation ◽  
Fluid Structure ◽  
Structure Interaction

scholarly journals Stereo-DIC Measurements of a Vibrating Bladed Disk: In-Depth Analysis of Full-Field Deformed Shapes

2021 ◽  
Vol 11 (12) ◽  
pp. 5430
Author(s):  
Paolo Neri ◽  
Alessandro Paoli ◽  
Ciro Santus
Keyword(s):  
Single Point ◽  
Excitation Frequency ◽  
Phase Variation ◽  
Operating Conditions ◽  
Image Correlation ◽  
Response Analysis ◽  
Full Field ◽  
Low Speed ◽  
Bladed Disk ◽  
Depth Analysis

Vibration measurements of turbomachinery components are of utmost importance to characterize the dynamic behavior of rotating machines, thus preventing undesired operating conditions. Local techniques such as strain gauges or laser Doppler vibrometers are usually adopted to collect vibration data. However, these approaches provide single-point and generally 1D measurements. The present work proposes an optical technique, which uses two low-speed cameras, a multimedia projector, and three-dimensional digital image correlation (3D-DIC) to provide full-field measurements of a bladed disk undergoing harmonic response analysis (i.e., pure sinusoidal excitation) in the kHz range. The proposed approach exploits a downsampling strategy to overcome the limitations introduced by low-speed cameras. The developed experimental setup was used to measure the response of a bladed disk subjected to an excitation frequency above 6 kHz, providing a deep insight in the deformed shapes, in terms of amplitude and phase distributions, which could not be feasible with single-point sensors. Results demonstrated the system’s effectiveness in measuring amplitudes of few microns, also evidencing blade mistuning effects. A deeper insight into the deformed shape analysis was provided by considering the phase maps on the entire blisk geometry, and phase variation lines were observed on the blades for high excitation frequency.

scholarly journals Complex response analysis of a non-smooth oscillator under harmonic and random excitations

2021 ◽  
Vol 42 (5) ◽  
pp. 641-648
Author(s):  
Shichao Ma ◽  
Xin Ning ◽  
Liang Wang ◽  
Wantao Jia ◽  
Wei Xu
Keyword(s):  
Excitation Frequency ◽  
System Stability ◽  
Response Analysis ◽  
External Excitation ◽  
Stochastic Response ◽  
Impact Oscillator ◽  
Nonlinear Parameters ◽  
Bifurcation Phenomena ◽  
Mc Simulation ◽  
Smooth System

AbstractIt is well-known that practical vibro-impact systems are often influenced by random perturbations and external excitation forces, making it challenging to carry out the research of this category of complex systems with non-smooth characteristics. To address this problem, by adequately utilizing the stochastic response analysis approach and performing the stochastic response for the considered non-smooth system with the external excitation force and white noise excitation, a modified conducting process has proposed. Taking the multiple nonlinear parameters, the non-smooth parameters, and the external excitation frequency into consideration, the steady-state stochastic P-bifurcation phenomena of an elastic impact oscillator are discussed. It can be found that the system parameters can make the system stability topology change. The effectiveness of the proposed method is verified and demonstrated by the Monte Carlo (MC) simulation. Consequently, the conclusions show that the process can be applied to stochastic non-autonomous and non-smooth systems.

Seismic Response Analysis of Soil-Structure Interaction on Base Isolation Structure

2013 ◽  
Vol 663 ◽  
pp. 87-91
Author(s):  
Ying Bo Pang
Keyword(s):  
Finite Element ◽  
Seismic Response ◽  
Soil Structure ◽  
Base Isolation ◽  
Soil Structure Interaction ◽  
Response Analysis ◽  
Analysis Model ◽  
Seismic Response Analysis ◽  
Structure Interaction ◽  
Calculation Results

As an effective way of passive damping, isolation technology has been widely used in all types of building structures. Currently, for its theoretical analysis, it usually follows the rigid foundation assumption and ignores soil-structure interaction, which results in calculation results distortion in conducting seismic response analysis. In this paper, three-dimensional finite element method is used to establish finite element analysis model of large chassis single-tower base isolation structure which considers and do not consider soil-structure interaction. The calculation results show that: after considering soil-structure interaction, the dynamic characteristics of the isolation structure, and seismic response are subject to varying degrees of impact.

Applications of the Impedance Method on Multiple Piezoelectric Actuators Driven Structures

2000 ◽  
Vol 123 (2) ◽  
pp. 262-268 ◽  
Author(s):  
C. C. Cheng ◽  
P. W. Wang
Keyword(s):  
System Modeling ◽  
Excitation Frequency ◽  
Vibration Response ◽  
Impedance Method ◽  
Dynamic Interactions ◽  
Active Structure ◽  
Impedance Model ◽  
Proposed Model ◽  
Host Structure ◽  
Arbitrary Location

An impedance-based system modeling technique has been developed to determine the output forces of multiple piezoelectric (PZT) patch actuators on an active structure to produce a known vibration response. In the analysis of the dynamic response of a structure driven by multiple PZT patches, the proposed model includes not only the dynamic interactions between the PZT patch and the host structure but also the impedance couplings among PZT patches. Therefore this approach can apply to a structure with multiple PZT actuators. Furthermore, the bending stiffness and the thickness of a PZT patch that are proved to be important as increases of excitation frequency are included in the proposed impedance model. Examples are given to demonstrate how to synthesize a known vibration response and how to suppress vibration response at an arbitrary location on structures using this technique.

Vibration Response Analysis of Mistuned Bladed Disk With Under-Platform Damper: Effect of Variation of Contact Condition on Vibration Characteristics

2017 ◽  
Author(s):  
Yasutomo Kaneko
Keyword(s):  
Gas Turbine ◽  
Direct Method ◽  
Contact Condition ◽  
Vibration Response ◽  
Response Analysis ◽  
Friction Damper ◽  
Mass Model ◽  
Contact Conditions ◽  
Manufacturing Tolerance ◽  
Bladed Disk

Blades with a friction damper have been used in a steam turbine and a gas turbine to improve the blade reliability. In particular, for a gas turbine blade of the upstream stage, under-platform dampers have been widely used, where the damper pieces with various geometries are inserted into the platforms of the adjacent blades. The damper piece is designed so that its surface contacts the platform surface uniformly. However, the contact conditions of the damper piece (in other words, the equivalent stiffness and the damping caused by the damper piece) may change appreciably blade by blade because of the likes of manufacturing tolerance, blade deformation in operation, and wear of the damper piece. Therefore, it is essential to consider the mistuning effect caused by the variation of the contact condition of the damper piece in evaluating the vibration response of the bladed disk with the under-platform damper. In this study, a mistuned bladed disk with under-platform dampers is represented by the equivalent spring-mass model. Frequency response analysis and random response analysis are carried out using the direct method and Monte Carlo simulation. Carrying out an extensive parametric study, the effect of the variation of the contact condition caused by the damper piece on the vibration response of the bladed disk is clarified.

Seismic Response Analysis of Liaocheng Guangyue Tower

2015 ◽  
Vol 744-746 ◽  
pp. 911-914
Author(s):  
Zhao Bo Meng ◽  
Guan Dong Qiao ◽  
Jie Jin
Keyword(s):  
Seismic Response ◽  
Soil Structure ◽  
Natural Frequencies ◽  
Timber Structure ◽  
Soil Structure Interaction ◽  
Response Analysis ◽  
Actual Situation ◽  
Seismic Response Analysis ◽  
Structure Interaction ◽  
Rare Earthquake

This paper establishes three models using ANSYS, which were timber structure of Guangyue Tower, timber structure-tower base and timber structure-tower base-foundation. The first 3 natural frequencies of timber structure respectively were 0.8524Hz、1.1273 Hz and 1.7426 Hz through modal analysis, which were compared with calculations from code. Lanzhou Wave was chosen to analyze the seismic response of Guangyue Tower, and the amplitudes were adjusted to 55gal and 310gal respectively according to the frequent earthquake and rare earthquake, which were inputted to the above models. As can be seen from the calculations, the maximum displacements of the three models were in the top nodes, and tower base had a greater impact on vibration of timber structure, which could not be ignored in seismic response analysis; considering soil-structure interaction in seismic response analysis could better reflect the actual situation of Guangyue Tower.

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