Search | Engineering

订阅投稿

首页工程期刊工程焦点工程成就工程前沿关于我们 English

资源类型

期刊论文 271

会议视频 2

年份

2023 11

2022 12

2021 20

2020 12

2019 13

2018 14

2017 13

2016 9

2015 10

2014 14

2013 10

2012 16

2011 15

2010 12

2009 22

2008 14

2007 22

2006 7

2005 7

2004 2

展开︾

关键词

应力 3

应力状态 3

残余应力 3

DX桩 2

内禀尺度 2

应力波 2

强度理论 2

有限元 2

D1 turnover / photoinhibition / photoprotection / photosynthesis / tomato / xanthophyll cycle 1

H2S应力腐蚀 1

LED灯具；加速老化测试；中位寿命；滑动平均误差 1

TC4钛合金 1

ZN-1阻尼橡胶材料 1

k-ε模型 1

一维应力波 1

三向受力状态 1

三塔悬索桥 1

不等围压 1

中药 1

展开︾

检索范围：

排序：展示方式：

Numerical analysis of vehicle-bridge coupling vibration concerning nonlinear stress-dependent damping

Pengfei LI; Jinquan ZHANG; Shengqi MEI; Zhenhua DONG; Yan MAO

《结构与土木工程前沿（英文）》 2022年第16卷第2期页码 239-249 doi: 10.1007/s11709-021-0804-y

摘要： Damping is known to have a considerable influence on the dynamic behavior of bridges. The fixed damping ratios recommended in design codes do not necessarily represent the complicated damping characteristics of bridge structures. This study investigated the application of stress-dependent damping associated with vehicle-bridge coupling vibration and based on that investigation proposed the stress-dependent damping ratio. The results of the investigation show that the stress-dependent damping ratio is significantly different from the constant damping ratio (5%) defined in the standard specification. When vehicles travel at speeds of 30, 60, and 90, the damping ratios of the bridge model are 3.656%, 3.658%, and 3.671%, respectively. The peak accelerations using the regular damping ratio are 18.9%, 21.3%, and 14.5% of the stress-dependent damping ratio, respectively. When the vehicle load on the bridge is doubled, the peak acceleration of the mid-span node increases by 5.4 times, and the stress-related damping ratio increases by 2.1%. A corrugated steel-web bridge is being used as a case study, and the vibration response of the bridge is compared with the measured results. The acceleration response of the bridge which was calculated using the stress-dependent damping ratio is significantly closer to the measured acceleration response than that using the regular damping ratio.

关键词： vehicle-bridge vibration system dynamic analysis stress-dependent damping energy dissipation

HTML PDF 收藏

Dynamics of structural systems with various frequency-dependent damping models

Li LI,Yujin HU,Weiming DENG,Lei LÜ,Zhe DING

《机械工程前沿（英文）》 2015年第10卷第1期页码 48-63 doi: 10.1007/s11465-015-0330-5

摘要：

The aim of this paper is to present the dynamic analyses of the system involving various damping models. The assumed frequency-dependent damping forces depend on the past history of motion via convolution integrals over some damping kernel functions. By choosing suitable damping kernel functions of frequency-dependent damping model, it may be derived from the familiar viscoelastic materials. A brief review of literature on the choice of available damping models is presented. Both the mode superposition method and Fourier transform method are developed for calculating the dynamic response of the structural systems with various damping models. It is shown that in the case of non-deficient systems with various damping models, the modal analysis with repeated eigenvalues are very similar to the traditional modal analysis used in undamped or viscously damped systems. Also, based on the pseudo-force approach, we transform the original equations of motion with nonzero initial conditions into an equivalent one with zero initial conditions and therefore present a Fourier transform method for the dynamics of structural systems with various damping models. Finally, some case studies are used to show the application and effectiveness of the derived formulas.

关键词： damping viscoelasticity dynamic analysis mode superposition method Fourier transform method

HTML PDF 收藏

Effect of seismic wave propagation in massed medium on rate-dependent anisotropic damage growth in concrete

Alireza DANESHYAR, Hamid MOHAMMADNEZHAD, Mohsen GHAEMIAN

《结构与土木工程前沿（英文）》 2021年第15卷第2期页码 346-363 doi: 10.1007/s11709-021-0694-z

摘要： Seismic modeling of massive structures requires special caution, as wave propagation effects significantly affect the responses. This becomes more crucial when the path-dependent behavior of the material is considered. The coexistence of these conditions renders numerical earthquake analysis of concrete dams challenging. Herein, a finite element model for a comprehensive nonlinear seismic simulation of concrete gravity dams, including realistic soil–structure interactions, is introduced. A semi-infinite medium is formulated based on the domain reduction method in conjunction with standard viscous boundaries. Accurate representation of radiation damping in a half-space medium and wave propagation effects in a massed foundation are verified using an analytical solution of vertically propagating shear waves in a viscoelastic half-space domain. A rigorous nonlinear finite element model requires a precise description of the material response. Hence, a microplane-based anisotropic damage–plastic model of concrete is formulated to reproduce irreversible deformations and tensorial degeneration of concrete in a coupled and rate-dependent manner. Finally, the Koyna concrete gravity dam is analyzed based on different assumptions of foundation, concrete response, and reservoir conditions. Comparison between responses obtained based on conventional assumptions with the results of the presented comprehensive model indicates the significance of considering radiation damping and employing a rigorous constitutive material model, which is pursued for the presented model.

关键词： soil–structure interaction massed foundation radiation damping anisotropic damage

HTML PDF 收藏

Development of rocking constraint device with vertical damping capacity for three-dimensional base-isolated

《结构与土木工程前沿（英文）》 2023年第17卷第3期页码 350-367 doi: 10.1007/s11709-022-0923-0

摘要： A new rocking constraint device (RCD) is developed for three-dimensional (3D) base-isolated frame structures by connecting a custom-designed cylinder pair to provide vertical damping with replaceable damping components installed outside the cylinders when the superstructure undergoes translational motion, and rocking constraint capacity when the superstructure is susceptible to rocking. Theoretical formulas for calculating the damping and rocking constraint stiffness of the RCD are proposed. Two series of sinusoidal loading tests are conducted at different loading frequencies and amplitudes to verify the damping and rocking constraint performance of the RCD. The test results show that the cylinder without orifices on its piston can provide the desired damping with a replaceable damping component, and that the RCD can effectively suppress rocking. Although the vertical stiffness of an individual cylinder is affected by the location of the replaceable damping component and loading frequency, the average vertical stiffness of the two cylinders, which determines the rocking constraint stiffness of the RCD, is independent of the two factors. Comparisons of the test and theoretical results indicate that the errors of the proposed formulas for calculating the damping and rocking constraint stiffness of the RCD do not exceed 12.9% and 11.0%, respectively.

关键词： three-dimensional isolation rocking behavior rocking constraint device replaceable damping component sinusoidal test

HTML PDF 收藏

Approximation of structural damping and input excitation force

Mohammad SALAVATI

《结构与土木工程前沿（英文）》 2017年第11卷第2期页码 244-254 doi: 10.1007/s11709-016-0371-9

摘要： Structural dynamic characteristics are the most significant parameters that play a decisive role in structural damage assessment. The more sensitive parameter to the damage is the damping behavior of the structure. The complexity of structural damping mechanisms has made this parameter to be one of the ongoing research topics. Despite all the difficulties in the modeling of damping, there are some approaches like as linear and nonlinear models which are described as the energy dissipation throughout viscous, material or structural hysteretic and frictional damping mechanisms. In the presence of a mathematical model of the damping mechanisms, it is possible to estimate the damping ratio from the theoretical comparison of the damped and un-damped systems. On the other hand, solving the inverse problem of the input force estimation and its distribution to each SDOFs, from the measured structural responses plays an important role in structural identification process. In this paper model-based damping approximation method and a model-less structural input estimation are considered. The effectiveness of proposed methods has been carried out through analytical and numerical simulation of the lumped mass system and the results are compared with reference data. Consequently, high convergence of the comparison results illustrates the satisfactory of proposed approximation methods.

关键词： structural modal parameters damping identification method input excitation force identification Inverse problem

HTML PDF 收藏

Variable stiffness and damping magnetorheological isolator

Yang ZHOU, Xingyu WANG, Xianzhou ZHANG, Weihua LI

《机械工程前沿（英文）》 2009年第4卷第3期页码 310-315 doi: 10.1007/s11465-009-0039-4

摘要： This paper presents the development and characterization of a magnetorheological (MR) fluid-based variable stiffness and damping isolator. The prototype of the MR fluid isolator is fabricated, and its dynamic behavior is measured under various applied magnetic fields. The parameters of the model under various magnetic fields are identified, and the dynamic performance of the isolator is evaluated in simulation. Experimental results indicate that both the stiffness and damping capability of the developed MR isolator can be controlled by an external magnetic field.

关键词： magnetorheological (MR) fluid stiffness damping mathematical model dynamic performance parameter identification

HTML PDF 收藏

表面张力作用下柱形胶体的弹性失稳

黄殿武,乔玲,汪时机

《中国工程科学》 2007年第9卷第4期页码 50-54

摘要：

采用弹性理论研究了圆柱形胶体在表面张力作用下的弹性失稳问题；利用能量泛函变分的方法导出了发生弹性失稳的非经典边界条件，得到了失稳的判据方程。分析判据方程发现，弹性失稳与圆柱体的半径、内禀尺度和失稳波长相关。

关键词：柱形胶体弹性失稳内禀尺度表面效应

HTML PDF 收藏

Study of an artificial boundary condition based on the damping-solvent extraction method

Qiang XU, Jianyun CHEN, Jing LI, Mingming WANG

《结构与土木工程前沿（英文）》 2012年第6卷第3期页码 281-287 doi: 10.1007/s11709-012-0167-5

摘要： A new artificial boundary condition for time domain analysis of a structure-unlimited-foundation system was proposed. The boundary condition was based on the damping-solvent extraction method. The principle of the damping-solvent extraction method was described. An artificial boundary condition was then established by setting two spring-damper systems and one artificial damping limited region. A test example was developed to verify that the proposed boundary condition and model had high precision. Compared with the damping-solvent extraction method, this boundary condition is easier to be applied to finite element method (FEM)-based numerical calculations.

关键词： damping-solvent extraction method structure-unlimited-foundation system spring-damper system artificial damping limited region finite element method

HTML PDF 收藏

Effects of green roof damping and configuration on structural seismic response

《结构与土木工程前沿（英文）》页码 1133-1144 doi: 10.1007/s11709-023-0959-9

摘要： Sustainable structures are critical for addressing global climate change. Hence, their structural resilience or ability to recover from natural events must be considered comprehensively. Green roofs are a widely used sustainable feature that improve the environment while providing excellent occupant amenity. To expand their usage, their inherent damping and layout sensitivity to seismic performance are investigated in this study. The soil of a green roof can serve as a damper to dissipate the energy generated by earthquakes or other dynamic events. Results of preliminary analysis show that a green roof soil can increase localized damping by 2.5% under both dry and saturated conditions. Based on these findings, nonlinear time-history analyses are conducted on a three-story building in SAP2000 to monitor the structural behavior with and without a green roof. The increased damping in the green roof soil is beneficial to the structural performance, i.e., it reduces the building displacement and acceleration by 10% and 12%, respectively. Additionally, certain configurations are more effective and beneficial to the structural response than others, which suggests the possibility of design optimization. Based on the findings of this study, new methods of modeling and considering green roofs in structural design are established.

关键词： green infrastructure green roof structural resilience seismic design

HTML PDF 收藏

Fluid damping clearance in a control valve of injector

ZHANG Jianming, ZHANG Weigang, YANG Bing, WANG Yawei

《机械工程前沿（英文）》 2007年第2卷第4期页码 439-441 doi: 10.1007/s11465-007-0075-x

摘要： A force model of a control valve of injector is set up, and the changes of the fluid damping clearance are investigated on the basis of the results of the computational fluid dynamics (CFD) and the experiments of control valve of injector. Results indicate that a damping clearance of 0.02–0.03 mm between the poppet and the valve guide is the most sufficient to dampen any excessive control valve poppet bouncing.

关键词： control computational bouncing CFD excessive control

HTML PDF 收藏

A method of analysis for modal aero-damping of vibrating blade in incompressible flow

Jun XING, Lin LI,

《能源前沿（英文）》 2009年第3卷第4期页码 465-471 doi: 10.1007/s11708-009-0037-6

摘要： By establishing a research model for aero-damping in a uniform incoming flow, the three-dimension analytical algorithm of the modal aero-damping based on the equivalent viscous damping principle was established. The algorithm, which is suited for low-speed flow, to compute aero-damping is based on classical lift line theory in aerodynamics, according to the analytical solution of unsteady aerodynamic force. According to the analytical equations, the modal aero-damping ratio for different nature frequencies of blades in various fluid field conditions can be solved, and the factors to affect the aero-damping can be determined.The first bend and the first torsion’s modal aero-damping ratios of a compressor blade are calculated by using the above algorithms. The results show that the aero-damping cannot be neglected comparing with the structure damping. It reflects the coupling degree between the flow field and the structure field, so the aero-damping is significant to compute the stress and life of blade.

关键词： compressor different three-dimension analytical classical low-speed

HTML PDF 收藏

Development of a seismic design method based on response spectra for building structures

ZHOU Xiyuan, YU Ruifang

《结构与土木工程前沿（英文）》 2007年第1卷第2期页码 129-141 doi: 10.1007/s11709-007-0014-2

摘要： The assumption and problem of the mode-superposition response spectrum method in seismic design code is discussed based on a brief review of the development of the seismic design method for building structures. The scope of application for the classical damping theory is analyzed and the necessity of the research on mode-superposition method for non-classical damping is presented. The progresses on the mode superposition response spectrum theory are discussed. This includes: 1) the complex mode superposition method (in real form) for the non-classically damped linear system and the general calculation formula for the application of code; 2) the complex complete quadratic combination (CCQC) method for the non-classically damped linear system, which is based on the same assumptions as in deducing the complete quadratic combination (CQC) method which is popularly used in seismic design codes of many countries; 3) the complex complete quadratic combination with three components (CCQC3) method, which is a generalization of the CCQC method to the case of multi-components and multiple-support seismic excitations and deducing corresponding method; 4) the approach for calculation of seismic response of the non-classically damped system with overcritical damping and the calculation method of seismic response for the linear system with multiple eigenvalues; 5) the time-dependent CCQC (t) algorithm considering nonstationary earthquake ground motion; 6) an applied and effective method to solve the low order complex vector basis for the large linear non-classically damped system, which can be expediently used in practice to avoid the unknown errors coming from the forced uncoupling method; 7) bringing forward the concept of partial quadratic combination in order to reduce the calculation amount of CQC and CCQC methods, and studying the primary estimation-criterion. The reasonability and applicable scope of these methods are also briefly discussed in this paper.

关键词： generalization classical damping mode-superposition response calculation formula damping theory

HTML PDF 收藏

Dynamic characteristics analysis of active constrained layer damping plate with various boundary conditions

Jing LU, Yu XIANG, Qiao NI

《机械工程前沿（英文）》 2011年第6卷第4期页码 449-455 doi: 10.1007/s11465-011-0240-0

摘要：

Considering the direct and converse piezoelectric effect, expressions of piezoelectric membrane internal forces in the piezoelectric constrained layer were given. The control equations of the piezoelectric constrained layer and host plate were obtained in according with the thin plate theory. Based on the layer wised principle, the integrated first order differential equation of an active constrained layer damping (ACLD) plate was derived for the simply supported boundary condition. Then, this method was expanded to the ACLD plate with cantilever boundary condition by virtue of geometric analogy method. Employing the extended homogeneous capacity precision integration approach, a high precision semi-analytical method was proposed to analyze the dynamic characteristics of the ACLD plate with various boundary conditions. The comparison with the literature results has verified the accuracy and effectiveness of the present method.

关键词： active constrained layer damping (ACLD) plate dynamic characteristics semi-analytical method extended homogeneous capacity precision integration approach

HTML PDF 收藏

Data-driven approach to solve vertical drain under time-dependent loading

《结构与土木工程前沿（英文）》 2021年第15卷第3期页码 696-711 doi: 10.1007/s11709-021-0727-7

摘要： Currently, the vertical drain consolidation problem is solved by numerous analytical solutions, such as time-dependent solutions and linear or parabolic radial drainage in the smear zone, and no artificial intelligence (AI) approach has been applied. Thus, in this study, a new hybrid model based on deep neural networks (DNNs), particle swarm optimization (PSO), and genetic algorithms (GAs) is proposed to solve this problem. The DNN can effectively simulate any sophisticated equation, and the PSO and GA can optimize the selected DNN and improve the performance of the prediction model. In the present study, analytical solutions to vertical drains in the literature are incorporated into the DNN–PSO and DNN–GA prediction models with three different radial drainage patterns in the smear zone under time-dependent loading. The verification performed with analytical solutions and measurements from three full-scale embankment tests revealed promising applications of the proposed approach.

关键词： vertical drain artificial neural network time-dependent loading deep learning network genetic algorithm particle swarm optimization

HTML PDF 收藏

Design of damping valve for vehicle hydro pneumatic suspension

DONG Mingming, HUANG Hua, GU Lian

《机械工程前沿（英文）》 2008年第3卷第1期页码 97-100 doi: 10.1007/s11465-008-0014-5

摘要： According to the design features of a hydro pneumatic spring, the necessity of a separate damping valve is proposed. Based on a 1/4 vehicle linear suspension model, the optimum damping coefficient is worked out and the parameters of the damping valve are determined with the equivalent linearization method. A practical structure of the damping valve is proposed having a small size, high flowrate when the valve opens, and the ability of enduring high back pressure. Based on bench tests, the damping valve has been found to properly work and be suitable. The design method and damping valve structure are useful guides for hydro pneumatic suspension, especially for the design of heavy-duty vehicles.

关键词： ability pneumatic necessity flowrate equivalent linearization