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Uncertainty propagation analysis by an extended sparse grid technique

X. Y. JIA, C. JIANG, C. M. FU, B. Y. NI, C. S. WANG, M. H. PING

《机械工程前沿（英文）》 2019年第14卷第1期页码 33-46 doi: 10.1007/s11465-018-0514-x

摘要： In this paper, an uncertainty propagation analysis method is developed based on an extended sparse grid technique and maximum entropy principle, aiming at improving the solving accuracy of the high-order moments and hence the fitting accuracy of the probability density function (PDF) of the system response. The proposed method incorporates the extended Gauss integration into the uncertainty propagation analysis. Moreover, assisted by the Rosenblatt transformation, the various types of extended integration points are transformed into the extended Gauss-Hermite integration points, which makes the method suitable for any type of continuous distribution. Subsequently, within the sparse grid numerical integration framework, the statistical moments of the system response are obtained based on the transformed points. Furthermore, based on the maximum entropy principle, the obtained first four-order statistical moments are used to fit the PDF of the system response. Finally, three numerical examples are investigated to demonstrate the effectiveness of the proposed method, which includes two mathematical problems with explicit expressions and an engineering application with a black-box model.

关键词： uncertainty propagation analysis extended sparse grid maximum entropy principle extended Gauss integration Rosenblatt transformation high-order moments analysis

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High-order phase-field model with the local and second-order max-entropy approximants

Fatemeh AMIRI

《结构与土木工程前沿（英文）》 2019年第13卷第2期页码 406-416 doi: 10.1007/s11709-018-0475-5

摘要： We approximate the fracture surface energy functional based on phase-field method with smooth local maximum entropy (LME) and second-order maximum entropy (SME) approximants. The higher-order continuity of the meshfree methods such as LME and SME approximants allows to directly solve the fourth-order phase-field equations without splitting the fourth-order differential equation into two second-order differential equations. We will first show that the crack surface functional can be captured more accurately in the fourth-order model with smooth approximants such as LME, SME and B-spline. Furthermore, smaller length scale parameter is needed for the fourth-order model to approximate the energy functional. We also study SME approximants and drive the formulations. The proposed meshfree fourth-order phase-field formulation show more stable results for SME compared to LME meshfree methods.

关键词： second-order maximum entropy local maximum entropy second- and fourth-order phase-field models B-spline

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High-order moment methods for LRFD including random variables with unknown probability distributions

Zhao-Hui LU, Yan-Gang ZHAO, Zhi-Wu YU

《结构与土木工程前沿（英文）》 2013年第7卷第3期页码 288-295 doi: 10.1007/s11709-013-0210-1

摘要： The reliability-based load and resistance factors design (LRFD) has been widely used in the structural design codes. In almost all of the current reliability methods for the determination of the load and resistance factors, the basic random variables are assumed to have known probability distributions. However, in reality, the probability distributions of some of the basic random variables are often unknown due to the lack of statistical data. In this paper, the high-order moment methods for LRFD including random variables with unknown probability distributions are proposed. From the investigation of the present paper, it can be concluded that: 1) The load and resistance factors can be determined even when the probability distributions of the basic random variables are unknown; 2) The present method is convenient and more effective in estimating the load and resistance factors in practical engineering since it needs neither the iterative computation of derivatives nor any design points; 3) In the applicable range of the high-order moment method, although the load and resistance factors obtained by the proposed method may be different from those obtained by first order reliability method (FORM), the target mean resistances obtained by both methods are essentially the same.

关键词： high-order moment methods applicable range load and resistance factors target mean resistance

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Split-order consolidation optimization for online supermarkets: Process analysis and optimization models

《工程管理前沿（英文）》页码 499-516 doi: 10.1007/s42524-022-0221-5

摘要： The large-scale online supermarket is a newly emerging online retailing mode which brings great convenience to people. Online supermarkets are characterized by having large amounts of daily orders with potentially multiple items, diverse delivery times, and a high order-split rate. Multiple shipments for one order caused by order splitting result in high cost and disturbance and a large number of discarded consumable packages at online retailers and customers, causing severe damage to the environment. Accordingly, research on split-order consolidation fulfilment is critical for the advancement of the practice and theory in the context of highly complex online retailing. This paper first analyzes the characteristics and the challenges associated with the split-order consolidation problem that online supermarket is confronting and summarizes the new operational process of split-order consolidation fulfilment. Then, a time–space network optimization model is built, and its corresponding solution algorithm is presented to solve the questions of where and when to consolidate the split orders. Finally, the computation results of the numerical experiments are provided to verify the effectiveness of the algorithm, and a sensitivity analysis of the relevant parameters is performed. This work highlights the effect of order consolidation processes and fulfilment methods on the order fulfilment decision-making for online supermarkets. The purpose of this article is to help pave the way for more effective online supermarket management and order implementation.

关键词： online supermarkets split-order consolidation time–space network genetic algorithm

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动态变化滚珠丝杠进给系统的智能非同位控制策略

刘辉, 张俊, 赵万华

《工程（英文）》 2017年第3卷第5期页码 641-647 doi: 10.1016/J.ENG.2017.04.007

摘要：

滚珠丝杠进给驱动系统由于其细长的螺旋主轴和部件之间连接部分的灵活性，具有变化的高阶动态特性，并且当采用直线光栅尺进行直接位置测量时，它还具有非同位控制的明显特征。长期以来，动态特性和非同位状况一直是运动和振动控制困难的根源，它们还会降低轴的运动精度。在本研究中，考虑到灵活性及其变化，我们建立了基于频率的子结构动态模型，并充分研究了动态特性对位置变化的依赖，开发出由模态特征修正器（MCM）和智能自适应调整算法（ATA）组成的控制策略。MCM 由峰值滤波器和陷波滤波器组成，从而将设备动态变为虚拟同位系统，且可以避免控制溢出。使用人工神经网络（ANN）作为平滑参数插值器，可以实时更新滤波器的参数，以便应对进给驱动系统的动态变化。我们已经在实际的进给驱动系统中验证了所提出策略的有效性和鲁棒性。

关键词：滚珠丝杠进给驱动系统变化高阶动态非同位控制模态特征修正器智能自适应调整算法

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带有预设性能的高阶多输入多输出非线性系统自适应跟踪控制 Research Articles

王雪娆1,2,王庆领1,2,孙长银1,2

《信息与电子工程前沿（英文）》 2021年第22卷第7期页码 986-1001 doi: 10.1631/FITEE.2000145

摘要：本文针对一类不确定多输入多输出非线性系统提出一种基于观测器的自适应预设性能跟踪控制策略，同时考虑了系统中可能存在的不确定性。为估计被控系统中的不确定性以及外部扰动，本文构建了一类新颖的有限时间神经网络干扰观测器。此外，为保证系统可以达到预设性能，采用一类误差转换方法，可以将时变约束转换为一种等价的非时变约束。随后，基于障碍李雅普诺夫函数以及反步方法，提出一种基于观测器的跟踪控制策略。经证明，本文所设计的控制方法可以使闭环系统所有信号实现有界，跟踪误差满足预设的时变性能指标。最后，无人机系统数值仿真结果验证了所提控制策略的有效性。

关键词：自适应跟踪控制；预设性能；输入饱和；干扰观测器；神经网络

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戴星宇：New Findings in the Interplay between Carbon and Energy Markets during EU ETS Phase |||：Higher-OrderMoments and Timescales（2020年7月12日）

2022年06月10日

关键词：能源

非线性系统高阶微分反馈控制

齐国元,陈增强,袁著祉

《中国工程科学》 2003年第5卷第8期页码 35-44

摘要：基于这种思想设计了能高品质地提取量测信号的微分和高阶微分的高阶微分器（HOD, high order differentiator），该HOD参数少，容易调节，并给出其稳定性、收敛性和滤波特性的证明；另外，对带有未知扰动、模型未知的非线性SISO和MIMO系统分别设计了基于HOD的高阶微分反馈自适应控制器（HODFC, high order differentials feedback adaptive

关键词：高阶微分器高阶微分反馈控制器稳定性鲁棒性解耦控制

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Higher-order mode effects on the seismic performance of tall piers

Zhongguo GUAN, Jianzhong LI, Yan XU, Hao LU

《结构与土木工程前沿（英文）》 2011年第5卷第4期页码 496-502 doi: 10.1007/s11709-011-0131-9

摘要： A comprehensive analysis was conducted to investigate the seismic performance of a typical tall bridge pier through incremental dynamical analysis (IDA). The effect of higher-order modes was studied specifically. The results showed that higher-order modes significantly contributed to the structural seismic response and should not be neglected. Including these modes resulted in an additional hinge midway up the pier. No plastic hinge would occur at this location for conventional bridge piers. Higher-order modes also led to an out-of-phase response between the hinge rotation at the pier bottom and the displacement at the top. This means that the displacement-based seismic design method cannot correctly predict the mechanical state of the critical hinge and therefore is not suitable for use in the seismic design of tall piers. Mistakenly using the displacement-based seismic design method for tall piers may result in a seriously unsafe condition.

关键词： tall bridges higher-order mode effects incremental dynamic analysis

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Dynamic analysis of composite beam subjected to harmonic moving load based on the third-order shear deformation

Mohammad Javad REZVANIL, Mohammad Hossein KARGARNOVIN, Davood YOUNESIAN

《机械工程前沿（英文）》 2011年第6卷第4期页码 409-418 doi: 10.1007/s11465-011-0245-8

摘要：

The response of an infinite Timoshenko beam subjected to a harmonic moving load based on the third-order shear deformation theory (TSDT) is studied. The beam is made of laminated composite, and located on a Pasternak viscoelastic foundation. By using the principle of total minimum potential energy, the governing partial differential equations of motion are obtained. The solution is directed to compute the deflection and bending moment distribution along the length of the beam. Also, the effects of two types of composite materials, stiffness and shear layer viscosity coefficients of foundation, velocity and frequency of the moving load over the beam response are studied. In order to demonstrate the accuracy of the present method, the results TSDT are compared with the previously obtained results based on first-order shear deformation theory, with which good agreements are observed.

关键词： timoshenko composite beam pasternak viscoelastic foundation third-order shear deformation theory (TSDT) harmonic moving load

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改进的R/S方法与中国火灾数据的分析预测

付昱华,付安捷

《中国工程科学》 2004年第6卷第5期页码 39-44

摘要：

讨论工程和经济学领域中的R/S分析方法（重标极差方法）的若干改进及应用。对于全国火灾起数的分析，计算赫斯特指数H时应用2种新的数据分组方法；引入赫斯特指数的差值ΔH以利于判断下一年的火灾起数是否会激增；对于已计算出的赫斯特指数H进行R/S分析，得到一组新的赫斯特指数H₁，即赫斯特指数的赫斯特指数，以及相应的ΔH₁，依此类推可以得到高阶赫斯特指数及其差值H₂，ΔH₂，H₃，ΔH₃等；根据1950—1999年全国火灾起数，用R/S方法预测2000年全国火灾起数。

关键词： R/S分析重标极差方法高阶赫斯特指数全国火灾起数预测

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Multiscale RBF-based central high resolution schemes for simulation of generalized thermoelasticity problems

Hassan YOUSEFI, Alireza TAGHAVI KANI, Iradj MAHMOUDZADEH KANI

《结构与土木工程前沿（英文）》 2019年第13卷第2期页码 429-455 doi: 10.1007/s11709-018-0483-5

摘要： In this study, average-interpolating radial basis functions (RBFs) are successfully integrated with central high-resolution schemes to achieve a higher-order central method. This proposed method is used for simulation of generalized coupled thermoelasticity problems including shock (singular) waves in their solutions. The thermoelasticity problems include the LS (systems with one relaxation parameter) and GN (systems without energy dissipation) theories with constant and variable coefficients. In the central high resolution formulation, RBFs lead to a reconstruction with the optimum recovery with minimized roughness on each cell: this is essential for oscillation-free reconstructions. To guarantee monotonic reconstructions at cell-edges, the nonlinear scaling limiters are used. Such reconstructions, finally, lead to the total variation bounded (TVB) feature. As RBFs work satisfactory on non-uniform cells/grids, the proposed central scheme can handle adapted cells/grids. To have cost effective and accurate simulations, the multiresolution–based grid adaptation approach is then integrated with the RBF-based central scheme. Effects of condition numbers of RBFs, computational complexity and cost of the proposed scheme are studied. Finally, different 1-D coupled thermoelasticity benchmarks are presented. There, performance of the adaptive RBF-based formulation is compared with that of the adaptive Kurganov-Tadmor (KT) second-order central high-resolution scheme with the total variation diminishing (TVD) property.

关键词： central high resolution schemes RBFs higher order accuracy generalized thermoelasticity multiresolution-based adaptation

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Analysis of nonlinear channel friction inverse problem

CHENG Weiping, LIU Guohua

《结构与土木工程前沿（英文）》 2007年第1卷第2期页码 205-210 doi: 10.1007/s11709-007-0024-0

摘要： Based on the Backus-Gilbert inverse theory, the singular value decomposition (SVD) for general inverse matrices and the optimization algorithm are used to solve the channel friction inverse problem. The resolution and covariance friction inverse model in matrix form is developed to examine the reliability of solutions. Theoretical analyses demonstrate that the convergence rate of the general Newton optimization algorithm is in the second-order. The Wiggins method is also incorporated into the algorithm. Using the method, noise can be suppressed effectively, and the results are close to accurate solutions with proper control parameters. Also, the numerical stability can be improved.

关键词： singular SVD second-order covariance Theoretical

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Improved prediction of pile bending moment and deflection due to adjacent braced excavation

《结构与土木工程前沿（英文）》 doi: 10.1007/s11709-023-0961-2

摘要： Deep excavations in dense urban areas have caused damage to nearby existing structures in numerous past construction cases. Proper assessment is crucial in the initial design stages. This study develops equations to predict the existing pile bending moment and deflection produced by adjacent braced excavations. Influential parameters (i.e., the excavation geometry, diaphragm wall thickness, pile geometry, strength and small-strain stiffness of the soil, and soft clay thickness) were considered and employed in the developed equations. It is practically unfeasible to obtain measurement data; hence, artificial data for the bending moment and deflection of existing piles were produced from well-calibrated numerical analyses of hypothetical cases, using the three-dimensional finite element method. The developed equations were established through a multiple linear regression analysis of the artificial data, using the transformation technique. In addition, the three-dimensional nature of the excavation work was characterized by considering the excavation corner effect, using the plane strain ratio parameter. The estimation results of the developed equations can provide satisfactory pile bending moment and deflection data and are more accurate than those found in previous studies.

关键词： pile responses excavation prediction deflection bending moments

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An assemble-to-order production planning with the integration of order scheduling and mixed-model sequencing

Baoxi WANG, Zailin GUAN, Yarong CHEN, Xinyu SHAO, Ming JIN, Chaoyong ZHANG

《机械工程前沿（英文）》 2013年第8卷第2期页码 137-145 doi: 10.1007/s11465-013-0251-0

摘要：

For assemble-to-order enterprises, both order scheduling and mixed-model sequencing need to be taken into consideration in the formulation of order-oriented assembly plan. First, determining production priority for the received orders, and then conducting assembly sequence to the mixed-model products in each order. Order scheduling is aimed to ensure order delivery with the optimization goal of minimal total overdue time, while product sequencing is aimed to minimize the makespan so as to meet the requirement on completion time of the order. In the end, the paper establishes a mixed integer programming model based on an industrial case, and makes programming calculation with Xpress-MP to accomplish an order-oriented assembly plan conforming to actual production.

关键词： mixed-model assembly line assemble-to-order order scheduling sequencing