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 349

会议视频 1

年份

2023 15

2022 16

2021 36

2020 16

2019 15

2018 16

2017 13

2016 10

2015 14

2014 17

2013 12

2012 14

2011 14

2010 19

2009 23

2008 14

2007 23

2006 10

2005 12

2004 6

展开︾

关键词

冲击波 4

数值模拟 3

有限元 3

残余应力 3

DX桩 2

先进反应堆 2

发电 2

变形 2

可持续性 2

地震波 2

应力 2

应力波 2

应力状态 2

强度理论 2

混凝土 2

5G 1

60 GHz；天线阵列；线极化；圆极化；毫米波 1

BFT 1

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

展开︾

检索范围：

排序：展示方式：

Lamb wave propagation modeling for structure health monitoring

Xiaoyue ZHANG, Shenfang YUAN, Tong HAO

《机械工程前沿（英文）》 2009年第4卷第3期页码 326-331 doi: 10.1007/s11465-009-0045-6

摘要： This study aims to model the propagation of Lamb waves used in structure health monitoring. A number of different numerical computational techniques have been developed for wave propagation studies. The local interaction simulation approach, used for modeling sharp interfaces and discontinuities in complex media (LISA/SIM theory), has been effectively applied to numerical simulations of elastic wave interaction. This modeling is based on the local interaction simulation approach theory and is finally accomplished through the finite elements software Ansys11. In this paper, the Lamb waves propagating characteristics and the LISA/SIM theory are introduced. The finite difference equations describing wave propagation used in the LISA/SIM theory are obtained. Then, an anisotropic metallic plate model is modeled and a simulating Lamb waves signal is loaded on. Finally, the Lamb waves propagation modeling is implemented.

关键词： Lamb wave modeling LISA/SIM theory finite difference equation finite element

HTML PDF 收藏

New computational treatment of optical wave propagation in lossywaveguides

Jian-xin ZHU,Guan-jie WANG

《信息与电子工程前沿（英文）》 2015年第16卷第8期页码 646-653 doi: 10.1631/FITEE.1400406

摘要： In this paper, the optical wave propagation in lossy waveguides is described by the Helmholtz equation with the complex refractive-index, and the Chebyshev pseudospectral method is used to discretize the transverse operator of the equation. Meanwhile, an operator marching method, a one-way re-formulation based on the Dirichletto-Neumann (DtN) map, is improved to solve the equation. Numerical examples show that our treatment is more efficient.

关键词： Adjoint operator Orthogonal Chebyshev Pseudospectral method Dirichlet-to-Neumann map

HTML PDF 收藏

Simulation of viscoelastic behavior of defected rock by using numerical manifold method

Feng REN, Lifeng FAN, Guowei MA

《结构与土木工程前沿（英文）》 2011年第5卷第2期页码 199-207 doi: 10.1007/s11709-011-0102-1

摘要： Numerical simulations of longitudinal wave propagation in a rock bar with microcracks are conducted by using the numerical manifold method which has great advantages in the simulation of discontinuities. Firstly, validation of the numerical manifold method is carried out by simulations of a longitudinal stress wave propagating through intact and cracked rock bars. The behavior of the stress wave traveling in a one-dimensional rock bar with randomly distributed microcracks is subsequently studied. It is revealed that the highly defected rock bar has significant viscoelasticity to the stress wave propagation. Wave attenuation as well as time delay is affected by the length, quantity, specific stiffness of the distributed microcracks as well as the incident stress wave frequency. The storage and loss moduli of the defected rock are also affected by the microcrack properties; however, they are independent of incident stress wave frequency.

关键词： stress wave propagation defected rock numerical manifold method viscoelastic behavior storage modulus loss modulus

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

Adaptive simulation of wave propagation problems including dislocation sources and random media

Hassan YOUSEFI, Jamshid FARJOODI, Iradj MAHMOUDZADEH KANI

《结构与土木工程前沿（英文）》 2019年第13卷第5期页码 1054-1081 doi: 10.1007/s11709-019-0536-4

摘要： An adaptive Tikhonov regularization is integrated with an h-adaptive grid-based scheme for simulation of elastodynamic problems, involving seismic sources with discontinuous solutions and random media. The Tikhonov method is adapted by a newly-proposed detector based on the MINMOD limiters and the grids are adapted by the multiresolution analysis (MRA) via interpolation wavelets. Hence, both small and large magnitude physical waves are preserved by the adaptive estimations on non-uniform grids. Due to developing of non-dissipative spurious oscillations, numerical stability is guaranteed by the Tikhonov regularization acting as a post-processor on irregular grids. To preserve waves of small magnitudes, an adaptive regularization is utilized: using of smaller amount of smoothing for small magnitude waves. This adaptive smoothing guarantees also solution stability without over smoothing phenomenon in stochastic media. Proper distinguishing between noise and small physical waves are challenging due to existence of spurious oscillations in numerical simulations. This identification is performed in this study by the MINMOD limiter based algorithm. Finally, efficiency of the proposed concept is verified by: 1) three benchmarks of one-dimensional (1-D) wave propagation problems; 2) P-SV point sources and rupturing line-source including a bounded fault zone with stochastic material properties.

关键词： adaptive wavelet adaptive smoothing discontinuous solutions stochastic media spurious oscillations Tikhonov regularization minmod limiter

HTML PDF 收藏

Leakage location system for oil pipeline on basis of stress wave detection

WANG Bangfeng, CHEN Renwen

《机械工程前沿（英文）》 2008年第3卷第3期页码 307-312 doi: 10.1007/s11465-008-0047-9

摘要： An online monitoring system was developed for rapidly determining the exact location of the holing position in an oil pipeline by monitoring and analyzing the characteristics of the strain wave caused by the hole. The system has a master-slaver computer structure based on a remote wireless network. The master system takes charge of managing and controlling the whole system, identifying the holing stress wave, and calculating the holing position. The slaver system is responsible for sampling the strain wave signal from the pipeline. The characteristics of the strain wave signal are extracted by a Hilbert-Huang transform based on a signal processing approach. The exact holing position can be obtained by a time delay locating method with stress wave characteristics. The experimental results of the in-service pipeline show that the average locating error of the system is less than 10 m, the accuracy ratio for the holing alarm is more than 90%, and the time that the system takes to respond to the leakage is less than 10 s.

HTML PDF 收藏

On subsurface box-shaped lined tunnel under incident SH-wave propagation

《结构与土木工程前沿（英文）》 2021年第15卷第4期页码 948-960 doi: 10.1007/s11709-021-0740-x

摘要： In this paper, a half-plane time-domain boundary element method is applied to obtain the seismic ground response, including a subsurface box-shaped lined tunnel deployed in a linear homogenous elastic medium exposed to obliquely incident SH-waves. Only the boundary around the tunnel is required to be discretized. To prepare an appropriate model by quadratic elements, a double-node procedure is used to receive dual boundary fields at corners as well as change the direction of the normal vector. After encoding the method in a previously confirmed computer program, a numerical study is carried out to sensitize some effective parameters, including frequency content and incident wave angle for obtaining a surface response. The depth and impedance ratio of the lining are assumed to be unvaried. The responses are illustrated in the time and frequency domains as two/three-dimensional graphs. The results showed that subsurface openings with sharp corners distorted the propagation path of the anti-plane waves to achieve the critical states on the ground surface. The present approach can be proposed to civil engineers for preparing simple underground box-shaped models with angular boundaries.

关键词： box-lined tunnel half-plane BEM surface response SH-wave time-domain

HTML PDF 收藏

Prediction of the shear wave velocity

Amoroso SARA

《结构与土木工程前沿（英文）》 2014年第8卷第1期页码 83-92 doi: 10.1007/s11709-013-0234-6

摘要： The paper examines the correlations to obtain rough estimates of the shear wave velocity from non-seismic dilatometer tests (DMT) and cone penetration tests (CPT). While the direct measurement of is obviously preferable, these correlations may turn out useful in various circumstances. The experimental results at six international research sites suggest that the DMT predictions of from the parameters (material index), (horizontal stress index), (constrained modulus) are more reliable and consistent than the CPT predictions from (cone resistance), presumably because of the availability, by DMT, of the stress history index .

关键词： horizontal stress index shear wave velocity flat dilatometer test cone penetration test

HTML PDF 收藏

用改进的Boussinesq方程模拟潜堤上的波浪变形

郑永红,沈永明,吴修广,游亚戈

《中国工程科学》 2004年第6卷第4期页码 34-40

摘要：

研究了一种改进的Boussinesq方程，采用预报校正格式对该方程进行了数值离散，并对淹没潜堤上的波浪变形进行了数值模拟，从数值模拟结果和实测值的比较结果来看，该方程能较好地模拟波浪在潜堤上传播时波面的变形过程，可以用于实际中的波浪问题计算。这种改进的Boussinesq方程本身及其求解方法需做进一步的完善。研究结果为实际应用Boussinesq方程来研究复杂地形上的波浪传播提供一定的理论指导。

关键词：改进的Boussinesq方程数值模拟波浪变形潜堤

HTML PDF 收藏

超光速问题与电磁波异常传播

黄志洵

《中国工程科学》 2000年第2卷第10期页码 80-92

摘要：

讨论了超光速研究的历史背景和在狭义相对论框架内进行工作的可能性；指出已有的实验（用单光子、激光脉冲和微波）在量子隧穿过程中呈现出的超光速行为，是在特定物理条件下才有的。认为经典电报员方程与Klein-Gordon方程的相似，使得前者可用于粒子隧穿和超光速现象的研究。讨论了不久前发表的王力军博士的超光速实验，展望了超光速研究的未来。

关键词：超光速微波异常传播快子量子隧道过程消失模负群速

HTML PDF 收藏

Performance of fixed beam without interacting bars

Aydin SHISHEGARAN, Behnam KARAMI, Timon RABCZUK, Arshia SHISHEGARAN, Mohammad Ali NAGHSH, Mohammreza MOHAMMAD KHANI

《结构与土木工程前沿（英文）》 2020年第14卷第5期页码 1180-1195 doi: 10.1007/s11709-020-0661-0

摘要： Increasing the bending capacity of reinforced concrete (RC) elements is one of important topics in structure engineering. The goal of this study is to develop a transferred stress system (TSS) on longitudinal reinforcement bars for increasing the bending capacity of RC frames. The study is divided into two parts, i.e., experimental tests and nonlinear FE analysis. The experiments were carried out to determine the load-deflection curves and crack patterns of the ordinary and TSS fixed frame. The FE models were developed for simulating the fixed frames. The obtained load-deflection results and the observed cracks from the FE analysis and experimental tests are compared to evaluate the validation of the FE nonlinear models. Based on the validated FE models, the stress distribution on the ordinary and TSS bars were evaluated. We found the load carrying capacity and ductility of TSS fixed beam are 29.39% and 23.69% higher compared to those of the ordinary fixed beams. The crack expansion occurs on the ordinary fixed beam, although there are several crack openings at mid-span of the TSS fixed beam. The crack distribution was changed in the TSS fixed frame. The TSS fixed beam is proposed to employ in RC frame instead of ordinary RC beam for improving the performance of RC frame.

关键词： transferred stress system bending capacity crack opening crack propagation FE nonlinear model stress distribution

HTML PDF 收藏

非均质岩体中一维应力波演化过程分析

钟光复,王志亮,李永池

《中国工程科学》 2006年第8卷第5期页码 58-62

摘要：

地下球形药包爆轰后将产生很强的地震波，其传播受到多种因素的影响。把岩石介质的弹塑性帽盖模型耦合到有限差分法程序中，对一维爆轰波在非均质岩石体中的传播、演化机理进行了数值模拟与分析；着重探讨了一维应力波从“硬”岩石层进入“软”岩石层、从“软”岩石层进入“硬”岩石层时，波在形状和强度等方面的变化规律；同时探讨了岩石介质中存在的“软弱夹层”对一维应力波传播的影响。

关键词：岩石介质一维应力波帽盖模型传播与演化

HTML PDF 收藏

海底管线地震应力分析方法和建议

孙政策,段梦兰,刘立名,张文,陈德诚

《中国工程科学》 2003年第5卷第8期页码 76-80

摘要：

比较全面地分析并概述了海底管线抗震设计所面临的问题；结合工程应用，给出了解决这些问题的基本思路和建议，希望能够对海底管线抗震设计方法研究和抗震规范的制定提供一定的帮助。

关键词：海底管线地震波断裂带应力应变悬跨弯管

HTML PDF 收藏

地震波荷载作用下类岩石试样波形传播和裂纹扩展数值模拟研究 Article

张晓平, 张旗, 刘泉声, 肖锐铧

《工程（英文）》 2022年第17卷第10期页码 140-150 doi: 10.1016/j.eng.2021.09.023

摘要：

地震之后伴随的余震在地震诱发滑坡灾害中起着重要作用。主震中已对岩体造成了不同程度的损伤，这使得余震过程中岩体裂纹进一步发展和相互交互贯通过程更复杂。为了探究地震波荷载对类岩石试样破裂失稳过程的影响，通过采用基于颗粒元黏结模型（bonded-particle model, BPM）的数值方法，研究了在两个正交方向上循环地震波加载作用下的波传播规律和裂纹扩展过程。结果表明，由于计算试样尺寸（76 mm × 152 mm）远小于地震波纵波波长，试样内未观察到波的透射和反射现象；加载产生的裂纹均为微张拉裂纹，重复轴向地震波加载不能使微张拉裂纹进一步扩展；只有当加载方向由轴向变为侧向，再由侧向变为轴向时，裂纹才会进一步扩展并最终导致试样破坏。本文揭示了在地震波反射作用及余震作用下，大量滑坡灾害发生的内在机理。

关键词：地震波循环荷载裂纹扩展黏结模型

HTML PDF 收藏

Some remarks on the engineering application of the fatigue crack growth approach under nonzero mean loads

Jorge Alberto Rodriguez DURAN,Ronney Mancebo BOLOY,Rafael Raider LEONI

《机械工程前沿（英文）》 2015年第10卷第3期页码 255-262 doi: 10.1007/s11465-015-0342-1

摘要：

The well-known fatigue crack growth (FCG) curves are two-parameter dependents. The range of the stress intensity factor ?K and the load ratio R are the parameters normally used for describing these curves. For engineering purposes, the mathematical representation of these curves should be integrated between the initial and final crack sizes in order to obtain the safety factors for stresses and life. First of all, it is necessary to reduce the dependence of the FCG curves to only one parameter. ?K is almost always selected and, in these conditions, considered as the crack driving force. Using experimental data from literature, the present paper shows how to perform multiple regression analyses using the traditional Walker approach and the more recent unified approach. The correlations so obtained are graphically analyzed in three dimensions. Numerical examples of crack growth analysis for cracks growing under nominal stresses of constant amplitude in smooth and notched geometries are performed, assuming an identical material component as that of the available experimental data. The resulting curves of crack size versus number of cycles (a vs. N) are then compared. The two models give approximately the same (a vs. N) curves in both geometries. Differences between the behaviors of the (avs. N) curves in smooth and notched geometries are highlighted, and the reasons for these particular behaviors are discussed.

关键词： fatigue crack propagation modeling life prediction mean stress effects