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DX桩 6

沉降 3

悬索桥 2

承载力 2

模型试验 2

病毒载量 2

Chebyshev多项式 1

FLTD型脉冲加速器 1

L唱M算法 1

MSJPDA 1

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三峡升船机 1

中间塔 1

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Distribution of background equivalent static wind load on high-rise buildings

Jianguo ZHANG , Ming GU ,

《结构与土木工程前沿（英文）》 2009年第3卷第3期页码 241-248 doi: 10.1007/s11709-009-0036-z

摘要： In this paper, the along-wind and cross-wind fluctuating load distributions along the height of high-rise buildings and their correlations are obtained through simultaneous pressure measurements in a wind tunnel. Some typical methods proposed in some relative literatures, i.e., load-response correlation (LRC), and quasi-mean load (QML) and gust load envelope (GLE) methods, are verified in terms of their accuracy in describing the background equivalent static wind load distribution on high-rise buildings. Based on the results, formulae of the distribution of background equivalent static load on high-rise buildings with typical shapes are put forward. It is shown that these formulae are of high accuracy and practical use.

关键词： high-rise buildings along-wind cross-wind background equivalent static wind load close formulae

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Estimation of composite load model with aggregate induction motor dynamic load for an isolated hybrid

Nitin Kumar SAXENA,Ashwani Kumar SHARMA

《能源前沿（英文）》 2015年第9卷第4期页码 472-485 doi: 10.1007/s11708-015-0373-7

摘要： It is well recognized that the voltage stability of a power system is affected by the load model and hence, to effectively analyze the reactive power compensation of an isolated hybrid wind-diesel based power system, the loads need to be considered along with the generators in a transient analysis. This paper gives a detailed mathematical modeling to compute the reactive power response with small voltage perturbation for composite load. The composite load is a combination of the static and dynamic load model. To develop this composite load model, the exponential load is used as a static load model and induction motors (IMs) are used as a dynamic load model. To analyze the dynamics of IM load, the fifth, third and first order model of IM are formulated and compared using differential equations solver in Matlab coding. Since the decentralized areas have many small consumers which may consist large numbers of IMs of small rating, it is not realistic to model either a single large rating unit or all small rating IMs together that are placed in the system. In place of using a single large rating IM, a group of motors are considered and then the aggregate model of IM is developed using the law of energy conservation. This aggregate model is used as a dynamic load model. For different simulation studies, especially in the area of voltage stability with reactive power compensation of an isolated hybrid power system, the transfer function of the composite load is required. The transfer function of the composite load is derived in this paper by successive derivation for the exponential model of static load and for the fifth and third order IM dynamic load model using state space model.

关键词： isolated hybrid power system (IHPS) composite load model static load dynamic load induction motor load model aggregate load

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ANN-based empirical modelling of pile behaviour under static compressive loading

Abdussamad ISMAIL

《结构与土木工程前沿（英文）》 2018年第12卷第4期页码 594-608 doi: 10.1007/s11709-017-0446-2

摘要： Artificial neural networks have been widely used over the past two decades to successfully develop empirical models for a variety of geotechnical problems. In this paper, an empirical model based on the product-unit neural network (PUNN) is developed to predict the load-deformation behaviour of piles based SPT values of the supporting soil. Other parameters used as inputs include particle grading, pile geometry, method of installation as well as the elastic modulus of the pile material. The model is trained using full-scale pile loading tests data retrieved from FHWA deep foundations database. From the results obtained, it is observed that the proposed model gives a better simulation of pile load-deformation curves compared to the Fleming’s hyperbolic model and t-z approach.

关键词： piles in compression load-deformation behaviour product-unit neural network

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Finding buckling points for nonlinear structures by dynamic relaxation scheme

Mohammad REZAIEE-PAJAND, Hossein ESTIRI

《结构与土木工程前沿（英文）》 2020年第14卷第1期页码 23-61 doi: 10.1007/s11709-019-0549-z

摘要： Dynamic Relaxation Method (DRM) is an explicit approach for solving the simultaneous systems of equations. In this tactic, the fictitious mass and damping are added to the static governing equations, and an artificial dynamic system is constructed. By using DRM for nonlinear analysis, the structural static equilibrium path is obtained. This outcome is extremely valuable, since it leads to the behavior of structures. Among the finding related to the structural static path are the critical and buckling points for nonlinear structures. In this paper, a new way for calculating the load factor is proposed by setting the external work zero. Mixing the dynamic relaxation scheme with external work technique has not been formulated so far. In all incremental-iterative methods, the load factor increment sign should be determinated by extra calculations. This sign leads to increase or decrease of the load increment. It is worth emphasizing that sign of the load factor increment changes at the load limit points. Therefore, the sign determinations are required in the common work control methods. These disadvantages are eliminated in the proposed algorithm. In fact, the suggested load factor depends only on the Dynamic Relaxation (DR) fictitious parameters. Besides, all DR calculations are performed via vector operation. Moreover, the load factor is calculated only by one formula, and it has the same relation in the all solution processes. In contrast to the arc length techniques, which requires the sign determined, the proposed scheme does not need any sign finding. It is shown that author’s technique is quicker than the other dynamic relaxation strategies. To prove the capability and efficiency of the presented scheme, several numerical tests are performed. The results indicate that the suggested approach can trace the complex structural static paths, even in the snap-back and snap-through parts.

关键词： load factor external work dynamic relaxation static equilibrium path large displacement

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Distributed fiber optic monitoring of a CFA pile with a central reinforcement bar bundle

Yi RUI, Nicholas de BATTISTA, Cedric KECHAVARZI, Xiaomin XU, Mei YIN

《结构与土木工程前沿（英文）》 2021年第15卷第1期页码 167-176 doi: 10.1007/s11709-020-0581-z

摘要： In this paper, we present an application of distributed fiber optic sensor (DFOS) technology to measure the strain of a continuous flight auger (CFA) test pile with a central reinforcement bar bundle, during a static load test carried out in London. Being distributed in nature, DFOS gives much more information about the pile performance as compared to traditional point sensors, such as identifying cross-sectional irregularities or other anomalies. The strain profiles recorded along the depth of the piles from the DFOS were used to calculate pile deformation (contraction), shaft friction, and tip resistance under various loads. Based on this pile load test, a finite element (FE) analysis was performed using a one-dimensional nonlinear load-transfer model. Calibrated by the shaft friction and tip resistance derived from the monitored data, the FE model was able to simulate the pile and soil performance during the load testing with good accuracy. The effect of the reinforcement cage and central reinforcement bar bundle were investigated, and it was found that the addition of a reinforcement cage would reduce the pile settlement by up to 20%.

关键词： continuous flight auger pile static load test central reinforcement bar bundle distributed fiber optic sensor finite element load transfer

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Damage detection in beam-like structures using static shear energy redistribution

《结构与土木工程前沿（英文）》 2022年第16卷第12期页码 1552-1564 doi: 10.1007/s11709-022-0903-4

摘要： In this study, a static shear energy algorithm is presented for the damage assessment of beam-like structures. According to the energy release principle, the strain energy of a damaged element suddenly changes when structural damage occurs. Therefore, the change in the static shear energy is employed to determine the damage locations in beam-like structures. The static shear energy is derived from the spectral factorization of the elementary stiffness matrix and structural deflection variation. The advantage of using shear energy as opposed to total energy is that only a few deflection data points of the beam structure are required during the process of damage identification. Another advantage of the proposed approach is that damage detection can be performed without establishing a structural finite-element model in advance. The proposed technique is first validated using a numerical example with single, multiple, and adjacent damage scenarios. A channel steel beam and rectangular concrete beam are employed as experimental cases to further verify the proposed approach. The results of the simulation and experiment examples indicate that the proposed algorithm provides a simple and effective method for defect localization in beam-like structures.

关键词： damage detection beam structure strain energy static displacement variation energy damage index

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DX桩与后压浆钻孔灌注桩现场试验研究

刘春刚,柴小兵,欧阳义,贺德新

《中国工程科学》 2012年第14卷第1期页码 80-85

摘要：

对DX桩进行了现场竖向抗压静载试验，并与后压浆直孔灌注桩进行了比较。结果表明，DX桩和后压浆钻孔灌注桩都可以提高桩的承载力和控制桩的沉降，4根试验桩的试验效果相差不大，但DX桩能以桩径小、桩长短满足大承载力的桩基，达到极限承载力时，混凝土的单方承载力是后压浆钻孔灌注桩的1.5倍，可以减少工程材料，降低工程造价；且DX桩施工工艺更简单，能加快施工进度。

关键词： DX桩静载荷试验承载力沉降

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基于惯性能时空最优分布的高加速轻载机构精密定位方法 Article

陈新,白有盾,杨志军,高健,陈贡发

《工程（英文）》 2015年第1卷第3期页码 391-398 doi: 10.15302/J-ENG-2015063

摘要：

高速运动精密定位是微电子封装设备中高加速轻载执行机构的基本运动需求。本文推导了高加速机构瞬态非线性动力学响应方程，揭示了刚度、频率、阻尼 (与材料空间布局相关) 和驱动频率 (与运动规划相关) 是主要影响因素。据此，在满足高加速机构精密定位的条件下，笔者提出了一种基于最优非线性动力学响应的结构优化和速度规划新方法。在结构优化中，首先分析了目前流行的基于等效静态载荷的柔性多体动力学优化方法未充分考虑惯性载荷的不足，然后提出了基于等效模态的柔性多体动力学最优动态响应优化新方法；在速度规划上，针对传统的几何光滑方法不能反映系统动态特性的缺陷，提出了基于变边界条件非线性动力学响应优化的速度规划新方法。将所提方法应用到高速固晶焊头的优化设计中，通过结构优化，降低振幅超过20%，再经非对称变加速规划，缩短定位时间超过40%。本文提出的方法为微电子封装类装备等高加速轻载机构精密定位的实现提供了有效的理论支撑和解决途径。

关键词：高加速轻载机构精密定位时空分布惯性能等效静态载荷方法速度规划

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DX桩在桥梁基础中的应用

张德华,齐万鹏,贺德新,贺建东,孙君平,郭桂霞

《中国工程科学》 2012年第14卷第1期页码 65-68

摘要：

DX桩以其单桩承载力高沉降量小的优点，在一般工业与民用建筑中得到了比较广泛的应用。最近一些桥梁工程也采用了这种新型桩技术。以北京市某桥梁工程为实例，通过试桩抗压静荷载试验，得出单桩竖向抗压承载力试验值，并且从单桩竖向抗压承载力、桩沉降量方面与直孔桩作了比较，还简单地分析了DX桩在受到竖向荷载作用时轴力沿桩身的分布情况以及在加载过程中DX桩上下盘盘阻的变化情况。

关键词： DX桩承载力桥梁静载荷实验

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Static balancing of planar articulated robots

Giuseppe QUAGLIA,Zhe YIN

《机械工程前沿（英文）》 2015年第10卷第4期页码 326-343 doi: 10.1007/s11465-015-0355-9

摘要：

Static balancing for a manipulator’s weight is necessary in terms of energy saving and performance improvement. This paper proposes a method to design balancing devices for articulated robots in industry, based on robotic dynamics. Full design details for the balancing system using springs are presented from two aspects: One is the optimization for the position of the balancing system; the other is the design of the spring parameters. As examples, two feasible balancing devices are proposed, based on different robotic structures: The first solution consists of linkages and springs; the other consists of pulleys, cross mechanisms and (hydro-) pneumatic springs. Then the two solutions are compared. Pneumatic, hydro-pneumatic and mechanical springs are discussed and their parameters are decided according to the requirements of torque compensation. Numerical results show that with the proper design using the methodology presented in this paper, an articulated robot can be statically balanced perfectly in all configurations. This paper therefore provides a design method of the balancing system for other similar structures.

关键词： robotics static balancing pneumatic spring mechanical spring torque compensation

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微分和表观静摩擦系数的表式

王渭源

《中国工程科学》 2001年第3卷第8期页码 29-32

摘要：

当前，工程师和科学家都对微牛和纳牛量级载荷静摩擦系数（以下简称微牛纳牛静摩擦系数）很感兴趣。但文献中至今没有详细讨论过微牛纳牛静摩擦系数与载荷的关系，而且发表的实验结果都不相互讨论。从微分静摩擦系数的定义出发，导出几种典型模型下微分静摩擦系数和表观静摩擦系数的表式，并据此广泛讨论这些文献中的实验结果。

关键词：微分静摩擦系数微牛纳牛静摩擦系数表观静摩擦系数宏观静摩擦系数

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Micromechanics model for static and dynamic strength of concrete under confinement

ZHENG Dan

《结构与土木工程前沿（英文）》 2008年第2卷第4期页码 329-335 doi: 10.1007/s11709-008-0044-4

摘要： The process of propagation, kinking of micro-cracks in concrete and the interaction among cracks as well as the induced failure were analyzed using the model that describes the wing type crack from the point of view of micromechanics. The pseudo-force method is applied to calculate the compressive strength factor of kinky propagated crack taking into account the effect of interaction among cracks. On the assumption that the micro fracture toughness of concrete does not vary with stain rate, the static and dynamic strength of concrete under different confinements can be calculated. The comparison of calculation result with experimental data indicates that a good agreement is achieved which implies that the model can be used to explain the rate-dependent properties of concrete in multi-axial stress state.

关键词： comparison different interaction pseudo-force toughness

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Evaluation of the static and dynamic structural performance of segmental pre-stressed concrete box girder

Ali Fadhil NASER, Zonglin WANG

《结构与土木工程前沿（英文）》 2013年第7卷第2期页码 164-177 doi: 10.1007/s11709-013-0196-8

摘要： The objectives of this study are to explain the repairing and strengthening methods which are used to improve the structural performance of the bridge structure, to analyze the static and dynamic responses after strengthening, and to evaluate the performance of the bridge structure after repairing and strengthening. The methods of repairing and strengthening include reconstruction the deck of the bridge by casting 10 cm layer of concrete, strengthening the web and bottom floor of box girders of middle spans and side spans by sticking the steel plates, strengthening the whole bridge structure by using external pre-stressing tendons, and treatment the cracks. The results of theoretical analysis show that the values of tensile stress and vertical deflection are decreased and the compressive stress is increased after strengthening. There are not tensile stresses are appeared in the sections of the bridge structure. The modal analysis results show that the value of natural frequency is equal to 2.09 Hz which is more than the values before strengthening which is equal to 1.64 Hz, indicating that the stiffness of the bridge structure is improved and the strengthening process is effective to improve the cracks resistance and bearing capacity of the bridge structure.

关键词： structural performance steel plates external pre-stressing cracks grouting method static

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Combined static mixers for high viscous fluids mixing

Zhenhao XI, Weizhen SUN, Ling ZHAO, Zhaoyan LIU

《化学科学与工程前沿（英文）》 2009年第3卷第1期页码 93-96 doi: 10.1007/s11705-009-0112-x

摘要： A new static mixer Cross-over-Disc has been invented to strip off the boundary layer and to make strong radial mixing. The pressure drop of Cross-over-Disc is 12—26 times as large as that of empty pipe with equivalent diameter and length. The mixing performance of Cross-over-Disc with 14 elements has been investigated in the viscosity range of 190—250 Pa?s by decoloration method, and the gray analysis of images shows that mixing inhomogeneity is about 7.5% and 9.4% for the mixing ratio of 5∶1 and 10∶1, respectively. Furthermore, mixing inhomogeneity for a combination of static mixing elements (four from Cross-over-Disc and three pairs from Sulzer-type) can be decreased to 2.1%—3.1% within a reasonable range of pressure drop.

关键词： static mixer Cross-over-Disc pressure drop mixing performance high viscous fluid

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Characteristics of metal magnetic memory signals of different steels under static tension

Yiliang ZHANG, Ruibin GOU, Jimin LI, Gongtian SHEN,

《机械工程前沿（英文）》 2010年第5卷第2期页码 226-232 doi: 10.1007/s11465-010-0012-2

摘要： To study the characteristics of metal magnetic memory (MMM) signals of different steels during tensile test, static tension tests were applied to 30 pieces of Q235 and 16MnR base metal and welded specimens. During the various deformation periods, MMM signals are tested, and micrometallographic is observed. Furthermore, the derivative of magnetic intensity (d/d) is analyzed by mathematical and statistical methods to study the macro and micro corresponding relationships and difference among magnetic signals. Results show that despite the different magnetic intensity () curves of different materials, their d/d patterns in the yielding and necking stages are the same; welded specimens have the similar magnetic signal curves with their base metal, and the welded structure does not interfere with its distribution; different materials have their unique zero point (＝0) before being fractured, which is independent of the fracture location; there is a direct relationship between the intragranular slip and the changes of magnetic signals, which indicates the uneven plastic deformation.

关键词： metal magnetic memory (MMM) magnetic intensity (H_p) static tension weld