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 441

会议视频 12

年份

2024 1

2023 31

2022 46

2021 29

2020 23

2019 24

2018 28

2017 37

2016 26

2015 23

2014 20

2013 18

2012 20

2011 15

2010 17

2009 15

2008 13

2007 25

2006 9

2005 4

展开︾

关键词

原子力显微镜 4

发展战略 4

能源 4

中国 2

力常数 2

对策建议 2

工程管理 2

技术预见 2

环境影响 2

键能 2

键长 2

2035年 1

360°表征 1

3D打印 1

Anderson 模型 1

BP神经网络 1

COVID-19 1

Casimir力 1

GDP年增长率 1

展开︾

检索范围：

排序：展示方式：

Non-convex sparse optimization-based impact force identification with limited vibration measurements

《机械工程前沿（英文）》 2023年第18卷第3期 doi: 10.1007/s11465-023-0762-2

摘要： Impact force identification is important for structure health monitoring especially in applications involving composite structures. Different from the traditional direct measurement method, the impact force identification technique is more cost effective and feasible because it only requires a few sensors to capture the system response and infer the information about the applied forces. This technique enables the acquisition of impact locations and time histories of forces, aiding in the rapid assessment of potentially damaged areas and the extent of the damage. As a typical inverse problem, impact force reconstruction and localization is a challenging task, which has led to the development of numerous methods aimed at obtaining stable solutions. The classical

ℓ 2

regularization method often struggles to generate sparse solutions. When solving the under-determined problem,

ℓ 2

regularization often identifies false forces in non-loaded regions, interfering with the accurate identification of the true impact locations. The popular

ℓ 1

sparse regularization, while promoting sparsity, underestimates the amplitude of impact forces, resulting in biased estimations. To alleviate such limitations, a novel non-convex sparse regularization method that uses the non-convex

ℓ 1 − 2

penalty, which is the difference of the

ℓ 1

and

ℓ 2

norms, as a regularizer, is proposed in this paper. The principle of alternating direction method of multipliers (ADMM) is introduced to tackle the non-convex model by facilitating the decomposition of the complex original problem into easily solvable subproblems. The proposed method named

ℓ 1 − 2 -ADMM

is applied to solve the impact force identification problem with unknown force locations, which can realize simultaneous impact localization and time history reconstruction with an under-determined, sparse sensor configuration. Simulations and experiments are performed on a composite plate to verify the identification accuracy and robustness with respect to the noise of the

ℓ 1 − 2 -ADMM

method. Results indicate that compared with other existing regularization methods, the

ℓ 1 − 2 -ADMM

method can simultaneously reconstruct and localize impact forces more accurately, facilitating sparser solutions, and yielding more accurate results.

关键词： impact force identification inverse problem sparse regularization under-determined condition alternating direction method of multipliers

HTML PDF 收藏

Impact force detection using an energy flow estimator with piezoelectric sensors

Xingjun WANG, Daniel GUYOMAR, Kaori YUSE, Mickaël LALLART, Lionel PETIT,

《机械工程前沿（英文）》 2010年第5卷第2期页码 194-203 doi: 10.1007/s11465-010-0004-2

摘要： Currently, there are numerous methods for estimating impact locations. One is to find more detailed information because the system becomes complicated. Another method is to reduce energy, for which various autonomic energy harvesting methods have been developed. However, the occupied energy is still small. This paper proposes a simple, rapid, and low-powered impact estimation method based on energy flow direction estimation through a pair of piezoelectric sensors. The estimation energy flow is expressed by a Poynting vector subsequently linked to piezoelectric sensor voltage outputs. The presented approach is verified by numerical simulations and experiments.

关键词： impact detection energy flow piezoelectric sensor thin plate

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

基于实测时间序列的非线性系统恢复力识别

许斌,贺佳

《中国工程科学》 2011年第13卷第9期页码 76-82

摘要：

提出一种完全基于激励和结构响应实测数据的结构动力系统非线性恢复力识别方法，并通过在一个4层钢结构模型中引入具有非线性特性的磁流变阻尼器（MR）模拟非线性恢复力，基于此模型结构在不同的激励方式下的动力响应测量数据，验证了该方法的有效性。对于结构的各自由度均受到激励的情况，运用最小二乘拟合算法识别出等效线性系统的物理参数（质量、刚度和阻尼矩阵），进而得到模型结构振动过程中MR阻尼力随时间变化情况并与实验实测结果进行了比较。针对结构仅在有限自由度上受到激励的情况，对以上方法进行了改进，提出了一种非线性系统恢复力的非参数化识别方法，利用结构中弹性恢复力的对称关系，分步确定了结构各层间恢复力模型，从而得到MR恢复力的大小并与实测结果进行了比较。结果表明，基于时域实测信号的非线性系统恢复力识别法在完整激励和非完整激励下均能有效地识别结构的非线性恢复力特性。文章所述方法可以运用于工程结构在动力荷载作用下的损伤发生发展过程的监测与识别。

关键词：非线性恢复力磁流变阻尼器最小二乘拟合等效线性系统非参数化模型

HTML PDF 收藏

Aerodynamic impact of train-induced wind on a moving motor-van

Jiajun HE; Huoyue XIANG; Yongle LI; Bin HAN

《结构与土木工程前沿（英文）》 2022年第16卷第7期页码 909-927 doi: 10.1007/s11709-022-0833-1

摘要： The newly-built single-level rail-cum-road bridge brings the issue of the aerodynamic impact of train-induced wind on road automobiles. This research introduced a validated computational fluid dynamics (CFD) model regarding this concern. Such an aerodynamic impact mechanism was explored; a relationship between the transverse distance between train and motor-van (hereinfafter referred to as van) and the aerodynamic effects on the van was explored to help the optimization of bridge decks, and the relationship between the automobile speed and aerodynamic variations of a van was fitted to help traffic control. The fitting results are accurate enough for further research. It is noted that the relative speed of the two automobiles is not the only factor that influences the aerodynamic variations of the van, even at a confirmed relative velocity, the aerodynamic variations of the van vary a lot as the velocity proportion changes, and the most unfavorable case shows an increase of over 40% on the aerodynamic variations compared to the standard case. The decay of the aerodynamic effects shows that not all the velocity terms would enhance the aerodynamic variations; the coupled velocity term constrains the variation amplitude of moments and decreases the total amplitude by 20%–40%.

关键词： rail-cum-road bridge aerodynamic impact train-induced wind CFD aerodynamic force quantitative analysis fitting

HTML PDF 收藏

Modeling limit force capacities of high force to volume lead extrusion dampers

《结构与土木工程前沿（英文）》 2021年第15卷第3期页码 609-622 doi: 10.1007/s11709-021-0724-x

摘要： Lead extrusion dampers are supplemental energy-dissipation devices that are used to mitigate seismic structural damage. Small volumetric sizes and high force capacities define high-force-to-volume (HF2V) devices, which can absorb significant response energy without sacrificial damage. However, the design of such devices for specific force capacities has proven difficult based on the complexities of their internal reaction mechanisms, leading to the adoption of empirical approaches. This study developed upper- and lower-bound force capacity estimates from analytical mechanics based on direct and indirect metal extrusion for guiding design. The derived equations are strictly functions of HF2V device geometric parameters, lead material properties, and extrusion mechanics. The upper-bound estimates from direct and indirect extrusion are denoted as (F_UB,1, F_UB,2) and (F_UB,3, F_UB,4), respectively, and the lower-bound estimates are denoted as (F_LB, F_LB,1) based on the combination of extrusion and friction forces. The proposed models were validated by comparing the predicted bounds to experimental force capacity data from 15 experimental HF2V device tests. The experimental device forces all lie above the lower-bound estimates (F_LB, F_LB,1) and below the upper-bound estimates (F_UB,1, F_UB,2, F_UB,4). Overall, the (F_LB, F_UB,2) pair provides wider bounds and the (F_LB,1, F_UB,4/F_UB,1) pair provides narrower bounds. The (F_LB,1, F_UB,1) pair has a mean lower-bound gap of 36%, meaning the lower bound was 74% of the actual device force on average. The mean upper-bound gap was 33%. The bulge area and cylinder diameter of HF2V devices are key parameters affecting device forces. These relatively tight bounds provide useful mechanics-based predictive design guides for ensuring that device forces are within the targeted design range after manufacturing.

关键词： extrusion lead dampers upper and lower bound analytical modelling limit force

HTML PDF 收藏

基于振动的超高速碰撞识别与定位 Research Article

包姣1,刘力夫2,曹九稳2,3

《信息与电子工程前沿（英文）》 2022年第23卷第4期页码 515-529 doi: 10.1631/FITEE.2000483

摘要：超高速碰撞（HVI）振动源识别与定位在载人航天器防护、机床碰撞损伤检测与定位等领域有着广泛应用。本文研究了基于同步压缩变换（SST）和纹理颜色分布（TCD）的冲击图像HVI源识别和定位算法。提出基于SST和TCD图像特征融合的HVI图像表示方法。为实现更精确的检测和定位，通过关联和评估样本标签与特征维度之间的相似性，获得最优选择性特征OSSST+TCD。将常用的分类和回归模型通过投票和堆叠融合，实现最终的检测和定位。基于所采集的3种高速子弹撞击铝合金板产生的HVI数据，验证了所提算法的有效性。实验结果表明本文提出的HVI识别与定位算法具有更高精准度。最后基于传感器分布，提出一种精确的四圆质心定位算法用于HVI源坐标定位。

关键词：集成学习；同步压缩变换；灰度共生矩阵；图像熵；距离估计

HTML PDF 收藏

Quality control based on electrode displacement and force in resistance spot welding

Chuntao JI, Lipeng DENG

《机械工程前沿（英文）》 2010年第5卷第4期页码 412-417 doi: 10.1007/s11465-010-0114-x

摘要： The behaviors of electrode displacement and force during spot welding under various conditions, such as different weld currents, electrode forces, and welding times, were studied. Tests were conducted on a 170?kVA MFDC spot welder. Data were collected via a multichannel high-speed data acquisition system and were analyzed with MATLAB. Behaviors of 5182 aluminum and mild steel in spot welding were compared. Results show that nugget expansion rate does not reach zero for aluminium as it does for mild steel as nugget grew to a certain size. A linear relationship is found between the nugget size and maximum expansion that facilitates online weld quality evaluation. An electrode force peak is observed and believed relevant to the sufficient nugget size.

关键词： aluminum electrode displacement electrode force nugget size data acquisition

HTML PDF 收藏

Visualization of force networks in 2D dense granular materials

Jianguo LIU, Qicheng SUN, Feng JIN,

《结构与土木工程前沿（英文）》 2010年第4卷第1期页码 109-115 doi: 10.1007/s11709-010-0003-8

摘要： Dense granular matter is a conglomeration of discrete solid and closely packed particles. As subjected to external loadings, the stress is largely transmitted by heavily stressed chains of particles forming a sparse network of larger contact forces. To understand the structure and evolution of force chains, a photoelastic technique was improved for determining stresses and strains in the assemblies of photoelastic granular disks in this paper. A two-dimensional vertical slab was designed. It contains 7200 polydispersed photoelastic disks and is subjected to a localized probe penetrating at the top of the slab to mimic the cone penetration test. The interparticle contact force distribution was found a peak around the mean value, a roughly exponential tail for greater force and a dip toward zero for smaller force. The force chain network around the probe tip was depicted, and the contact angle distribution of particles in force chains was found to be well aligned in the directions of major principal stress.

关键词： granular matter force chain multiscale modeling

HTML PDF 收藏

Motion/force transmission indices of parallel manipulators

Xinjun LIU, Chao WU, Fugui XIE

《机械工程前沿（英文）》 2011年第6卷第1期页码 89-91 doi: 10.1007/s11465-011-0215-1

HTML PDF 收藏

Applications of atomic force microscopy in immunology

Jiping Li, Yuying Liu, Yidong Yuan, Bo Huang

《医学前沿（英文）》 2021年第15卷第1期页码 43-52 doi: 10.1007/s11684-020-0769-6

摘要： Cellular mechanics, a major regulating factor of cellular architecture and biological functions, responds to intrinsic stresses and extrinsic forces exerted by other cells and the extracellular matrix in the microenvironment. Cellular mechanics also acts as a fundamental mediator in complicated immune responses, such as cell migration, immune cell activation, and pathogen clearance. The principle of atomic force microscopy (AFM) and its three running modes are introduced for the mechanical characterization of living cells. The peak force tapping mode provides the most delicate and desirable virtues to collect high-resolution images of morphology and force curves. For a concrete description of AFM capabilities, three AFM applications are discussed. These applications include the dynamic progress of a neutrophil-extracellular-trap release by neutrophils, the immunological functions of macrophages, and the membrane pore formation mediated by perforin, streptolysin O, gasdermin D, or membrane attack complex.

关键词： cellular mechanics atomic force microscopy neutrophil extracellular trap macrophage phagocytosis pore formation

HTML PDF 收藏

Variational mode decomposition based modal parameter identification in civil engineering

Mingjie ZHANG, Fuyou XU

《结构与土木工程前沿（英文）》 2019年第13卷第5期页码 1082-1094 doi: 10.1007/s11709-019-0537-3

摘要： An out-put only modal parameter identification method based on variational mode decomposition (VMD) is developed for civil structure identifications. The recently developed VMD technique is utilized to decompose the free decay response (FDR) of a structure into to modal responses. A novel procedure is developed to calculate the instantaneous modal frequencies and instantaneous modal damping ratios. The proposed identification method can straightforwardly extract the mode shape vectors using the modal responses extracted from the FDRs at all available sensors on the structure. A series of numerical and experimental case studies are conducted to demonstrate the efficiency and highlight the superiority of the proposed method in modal parameter identification using both free vibration and ambient vibration data. The results of the present method are compared with those of the empirical mode decomposition-based method, and the superiorities of the present method are verified. The proposed method is proved to be efficient and accurate in modal parameter identification for both linear and nonlinear civil structures, including structures with closely spaced modes, sudden modal parameter variation, and amplitude-dependent modal parameters, etc.

关键词： modal parameter identification variational mode decomposition civil structure nonlinear system closely spaced modes

HTML PDF 收藏

步行激励下大跨度钢-混凝土空心板组合梁振动舒适度研究 Article

刘界鹏, 黄鉥, 李江, Y. Frank Chen

《工程（英文）》 2022年第19卷第12期页码 93-104 doi: 10.1016/j.eng.2021.04.025

摘要：

大跨度预制钢-混凝土空心板组合梁（CBHCS）是一种新型的楼板结构，可用于各种大跨度结构。然而，人为引起的振动会对此类结构的使用产生影响。为了减轻振动，需要探究由人引起的步行力与楼板状态之间的关系。本文首先使用测力板获取了25 名测试者的150 个步行力，确定了单步行走的傅里叶级数中的动态载荷系数和相位角。其次，对7 个CBHCS试样进行了行走测试，获取了模态振型、固有频率、阻尼比和加速度等基本动态特性。CBHCS楼板系统通常表现出高频（>10 Hz）和低阻尼（阻尼比低于2%）的特性。本文还使用有限元方法进行了灵敏度研究，以研究CBHCS楼板系统的振动性能，考虑了楼板厚度、
钢梁类型、接触时间和人体重量。最后，本文推导了基频和峰值加速度的解析表达式，与实验结果吻合较好，具有实际的应用价值。

关键词：组合梁空心板步行力楼板振动模态振型

HTML PDF 收藏

Game theoretic analysis of environmental impact assessment system in China

CHENG Hongguang, PU Xiao, GONG Li, QI Ye

《环境科学与工程前沿（英文）》 2007年第1卷第4期页码 448-453 doi: 10.1007/s11783-007-0071-8

摘要： Environmental impact assessment (EIA) system has been established in China since 1973. In present EIA cases, there are four participants in general: governments, enterprises, EIA organizations and the public. The public has held re

关键词： public impact assessment Environmental impact general

HTML PDF 收藏

The research on structural damage identification using rough set and integrated neural network

Juelong LI, Hairui LI, Jianchun XING, Qiliang YANG

《机械工程前沿（英文）》 2013年第8卷第3期页码 305-310 doi: 10.1007/s11465-013-0259-5

摘要：

A huge amount of information and identification accuracy in large civil engineering structural damage identification has not been addressed yet. To efficiently solve this problem, a new damage identification method based on rough set and integrated neural network is first proposed. In brief, rough set was used to reduce attributes so as to decrease spatial dimensions of data and extract effective features. And then the reduced attributes will be put into the sub-neural network. The sub-neural network can give the preliminary diagnosis from different aspects of damage. The decision fusion network will give the final damage identification results. The identification examples show that this method can simplify the redundant information to reduce the neural network model, making full use of the range of information to effectively improve the accuracy of structural damage identification.

关键词： rough set integrated neural network damage identification decision making fusion