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关键词

严格雪崩准则 3

自相关函数 3

Walsh循环谱 2

Bent函数 1

Chrestenson谱 1

PID控制 1

SAC 1

Walsh谱 1

Walsh谱分解式 1

m值逻辑函数 1

假说—演绎方法 1

典型信息法 1

决策树；多类不平衡学习；节点划分准则；海林格距离；一对多技术 1

准则 1

分布 1

列车脱轨 1

动态拉伸本构模型 1

双向应力 1

变形速率比值判据 1

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Deformation control criterion of shield tunnel under lateral relaxation of soft soil

《结构与土木工程前沿（英文）》 2023年第17卷第5期页码 780-795 doi: 10.1007/s11709-023-0944-3

摘要： Metro shield tunnels under the lateral relaxation of soil (LRS) are susceptible to significant lateral deformations, which jeopardizes the structural safety and waterproofing. However, deformation control standards for such situations have not been clearly defined. Therefore, based on a specific case, a model test is conducted to realize the LRS of a shield tunnel in a sandy stratum to reveal its effect on segment liners. Subsequently, a deformation control criterion is established. The LRS is simulated by linearly reducing the loads applied to the lateral sides of the segment structure. During lateral unloading, the lateral earth pressure coefficient on the segment decreases almost exponentially, and the structural deformation is characterized by horizontal expansion at the arch haunches and vertical shrinkage at the arch vault and arch bottom. Based on the mechanical pattern of the segment structure and the acoustic emission, the deformation response of a segment can be classified into three stages: elastic and quasi-elastic, damage, and rapid deformation development. For a shield tunnel with a diameter of approximately 6 m and under the lateral relaxation of sandy soil, when the ellipticity of the segment is less than 2.71%, reinforcement measures are not required. However, the segment deformation must be controlled when the ellipticity is 2.71% to 3.12%; in this regard, an ellipticity of 3% can be used as a benchmark in similar engineering projects.

关键词： shield tunnel lateral relaxation of soil deformation control criterion of segment structure model test

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Experimental research on ductile fracture criterion in metal forming

Song YU, Weiming FENG

《机械工程前沿（英文）》 2011年第6卷第3期页码 308-311 doi: 10.1007/s11465-011-0233-z

摘要：

Ductile fracture criterion is key limitation parameter in material forming. Accuracy predicting surface and internal failure in plastic deformation process affects on the technology design of workpiece and die greatly. Tension, compression, torsion and shearing test on 45# steel are utilized for providing the experimental values of the critical values at fracture, and 11 widely used ductile fracture criterion are selected to simulate the physical experiments and their relative accuracy for predicting and quantifying fracture initiation sites are investigated. The comparing results show that metal forming process under high triaxiality can be estimated successively using both Normalized Cockcroft-latham and the Brozzo ductile fracture criteria, but the Ayada and general Rice-Tracey model work very well for the low triaxiality cases.

关键词： ductile fracture criteria metal forming process material experiment stress triaxiality

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A new fracture criterion for peridynamic and dual-horizon peridynamics

Jinhai ZHAO, Hesheng TANG, Songtao XUE

《结构与土木工程前沿（英文）》 2018年第12卷第4期页码 629-641 doi: 10.1007/s11709-017-0447-1

摘要： A new fracture criterion based on the crack opening displacement for peridynamic (PD) and dual-horizon peridynamics (DH-PD) is proposed. When the relative deformation of the PD bond between the particles reaches the critical crack tip opening displacement of the fracture mechanics, we assume that the bond force vanishes. A new damage rule similar to the local damage rule in conventional PD is introduced to simulate fracture. The new formulation is developed for a linear elastic solid though the extension to nonlinear materials is straightforward. The performance of the new fracture criterion is demonstrated by four examples, i.e. a bilateral crack problem, double parallel crack, monoclinic crack and the double inclined crack. The results are compared to experimental data and the results obtained by other computational methods.

关键词： Castigliano’s theorem breaking energy critical extension XFEM COD PD-COD

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一种损伤演化方程的建立和几种层裂准则的推导

曹结东,李永池

《中国工程科学》 2006年第8卷第1期页码 40-45

摘要：

通过唯象分析和细观统计相结合的方法建立了一种韧性材料的损伤演化方程，从物理上对方程中的参数进行了合理的解释，并以此为依据推导了材料的便于工程应用的几种层裂准则，根据准则总结了一些有意义的层裂规律；通过层裂实验和数值模拟相结合的方法来确定材料参数，计算结果与实验结果较好的一致性验证了所建的损伤演化方程和推导的层裂准则是合理的，决定材料参数的方法是有效的。

关键词：损伤演化方程层裂准则数值模拟

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钨合金的冲击拉伸行为及其本构和断裂判据的表述

张宝,丁淳彤,刘宝华,陈雪莲

《中国工程科学》 2003年第5卷第3期页码 44-50

摘要：

利用飞轮式Hopkinson拉杆实验技术对钨质量分数为93% 的钨合金在-50～100℃温度范围、应变率ε=10²～10³s^-1区间的动态拉伸性态进行了测试，提供了相应的σ-ε曲线和最大拉伸失效应变，并以此为依据建立了该合金动态拉伸行为的本构关系，提出了该合金受动载发生塑性失稳以致发生拉断的判据。利用断口分形分析理论，对试件拉伸断口微观特征所作的分析和对宏观力学性态实验所作的结论给予了有力的支持。

关键词：动态拉伸本构模型钨合金断裂失效判据

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安全性第一准则下的组合贷款模型

唐万生,严维真,宁玉富

《中国工程科学》 2007年第9卷第11期页码 137-141

摘要：

提出了一种在概率准则意义下的组合贷款模型，并设计了基于随机模拟的混合优化算法进行求解。该算法突破了各种贷款收益率必须服从正态分布的假定，可对贷款收益率是任意分布形式的模型进行求解。经数值仿真，验证了算法的可行性。

关键词：组合贷款安全性第一准则随机模拟遗传算法同步扰动随机逼近

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满足k阶严格雪崩准则的多值逻辑函数的谱特征

郭锦辉,李世取

《中国工程科学》 2005年第7卷第12期页码 45-48

摘要：

给出了剩余类环Z_m上逻辑函数的k阶严格雪崩准则(SAC)的概念, 用概率方法证明了m值逻辑函数满足高阶严格雪崩准则时一定满足低阶严格雪崩准则, 并借助Chrestenson谱给出了m值逻辑函数满足k阶严格雪崩准则的一个充分必要条件。

关键词： m值逻辑函数 Chrestenson谱自相关函数严格雪崩准则

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Application of the expanded distinct element method for the study of crack growth in rock-like materials under uniaxial compression

Lei YANG, Yujing JIANG, Bo LI, Shucai LI, Yang GAO

《结构与土木工程前沿（英文）》 2012年第6卷第2期页码 121-131 doi: 10.1007/s11709-012-0151-0

摘要： The expanded distinct element method (EDEM) was used to investigate the crack growth in rock-like materials under uniaxial compression. The tensile-shear failure criterion and the Griffith failure criterion were implanted into the EDEM to determine the initiation and propagation of pre-existing cracks, respectively. Uniaxial compression experiments were also performed with the artificial rock-like samples to verify the validity of the EDEM. Simulation results indicated that the EDEM model with the tensile-shear failure criterion has strong capabilities for modeling the growth of pre-existing cracks, and model results have strong agreement with the failure and mechanical properties of experimental samples. The EDEM model with the Griffith failure criterion can only simulate the splitting failure of samples due to tensile stresses and is incapable of providing a comprehensive interpretation for the overall failure of rock masses. Research results demonstrated that sample failure primarily resulted from the growth of single cracks (in the form of tensile wing cracks and shear secondary cracks) and the coalescence of two cracks due to the growth of wing cracks in the rock bridge zone. Additionally, the inclination angle of the pre-existing crack clearly influences the final failure pattern of the samples.

关键词： expanded distinct element method (EDEM) crack growth rock-like material tensile-shear failure criterion Griffith failure criterion mechanical and failure behavior

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面向运动估计器硬件实现的加权块匹配检测算法

张霞,郑南宁,张光烈,吴勇,王少瑞,徐维朴

《中国工程科学》 2002年第4卷第1期页码 47-53

摘要：

在各种视频处理算法中，运动补偿型算法大大提高了各种视频处理效果。运动估计器的硬件实现是各种运动补偿视频处理算法在实际系统中运用的关键。由于块匹配运动估计算法较低的运算复杂度和硬件实现难度以及块匹配检测标准函数很高的调用频率，已经广泛应用到各种实际系统中。文中提出了加权最小最大误差的匹配检测标准，能够降低运动估计器的运算复杂度，减少估计器的硬件面积，提高硬件速度，而且能够降低递归搜索块匹配运动估计算法固有误差传递带来的负面影响。

关键词：视频处理运动补偿运动估计块匹配检测标准

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变形速率比值判据与猫山隧道工程验证

李世煇,宋军

《中国工程科学》 2002年第4卷第6期页码 85-91

摘要：

为了初步解决新奥法隧道工程支护初期缺乏有效的、定量的围岩稳定性判据以及塌方事故多见的技术难题，文章论述了变形速率比值判据假说的依据，得出阈值的方法及应用中常的五种典型情况；猫山公路隧道施工中正反两方面的演绎证明，两个断面应用变形速率比值判据预报险情，化险为夷，另一断面中止应用此判据后，发生大塌方；变形速率比值判据是一种典型信息法，是一种假说—演绎方法，是从定性到定量综合集成法的一种初步应用。

关键词：开放的复杂巨系统塌方事故变形速率比值判据典型信息法假说—演绎方法综合集成法

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Modeling and analysis of magnetic dipoles in weak magnetic field

WANG Zhaoxia, ZHANG Weimin, LIU Hongguang

《机械工程前沿（英文）》 2008年第3卷第2期页码 222-225 doi: 10.1007/s11465-008-0028-z

摘要： The magnetic leakage field distribution resulting from linear defects of a tube sample in the geomagnetic field is modeled according to the magnetic dipole theory. The formula to compute the normal component of the weak magnetic field is deduced based on the spatial distribution of the magnetic dipole. The shape and characteristics of the zero line (an important criterion for magnetic memory testing) of the normal field is analyzed under different longitudinal magnetizations. Results show that the characteristics of the zero line should be considered when the metal magnetic memory testing method is used to find and locate the defect.

关键词： geomagnetic theory important criterion magnetic leakage normal component

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A pilot scale test of ozonization treatment of ethene wastewater for reuse

ZHONG Li, REN Wei, GUO Wenjing

《化学科学与工程前沿（英文）》 2008年第2卷第2期页码 191-195 doi: 10.1007/s11705-008-0028-x

摘要： A pilot scale test of advanced treatment of ethene wastewater by ozonization was carried out for industrial water reuse. Effects of different operating conditions on COD degradation, such as wastewater flow rate, ozonized gas flow rate, operating voltage of ozonizer and two ozone generation means, using pure oxygen or air, was investigated. The results show that the increase of ozonizer operating voltage, the decrease of wastewater flow rate and the suitable ozonized gas flow rate improve the removal of COD in wastewater and that ozone generated respectively from air and pure oxygen can effectively remove COD of ethene wastewater to meet the industrial water reuse criterion.

关键词： different industrial oxygen generation criterion

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Effect of interface adhesion factor on the bearing capacity of strip footing placed on cohesive soil overlying rock mass

《结构与土木工程前沿（英文）》 2021年第15卷第6期页码 1494-1503 doi: 10.1007/s11709-021-0768-y

摘要： The problem related to bearing capacity of footing either on pure soil or on pure rock mass has been investigated over the years. Currently, no study deals with the bearing capacity of strip footing on a cohesive soil layer overlying rock mass. Therefore, by implementing the lower bound finite element limit analysis in conjunction with the second-order cone programming and the power cone programming, the ultimate bearing capacity of a strip footing located on a cohesive soil overlying rock mass is determined in this study. By considering the different values of interface adhesion factor (α_cr) between the cohesive soil and rock mass, the ultimate bearing capacity of strip footing is expressed in terms of influence factor (I_f) for different values of cohesive soil layer cover ratio (T_cs/B). The failure of cohesive soil is modeled by using Mohr−Coulomb yield criterion, whereas Generalized Hoek−Brown yield criterion is utilized to model the rock mass at failure. The variations ofI_f with different magnitudes of α_cr are studied by considering the influence of the rock mass strength parameters of beneath rock mass layer. To examine stress distribution at different depths, failure patterns are also plotted.

关键词： bearing capacity soil-rock interface Hoek−Brown yield criterion plasticity limit analysis

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Progressive failure analysis of notched composite plate by utilizing macro mechanics approach

《结构与土木工程前沿（英文）》 2021年第15卷第3期页码 623-642 doi: 10.1007/s11709-021-0726-8

摘要： In this study, gradual and sudden reduction methods were combined to simulate a progressive failure in notched composite plates using a macro mechanics approach. Using the presented method, a progressive failure is simulated based on a linear softening law prior to a catastrophic failure, and thereafter, sudden reduction methods are employed for modeling a progressive failure. This combination method significantly reduces the computational cost and is also capable of simultaneously predicting the first and last ply failures (LPFs) in composite plates. The proposed method is intended to predict the first ply failure (FPF), LPF, and dominant failure modes of carbon/epoxy and glass/epoxy notched composite plates. In addition, the effects of mechanical properties and different stacking sequences on the propagation of damage in notched composite plates were studied. The results of the presented method were compared with experimental data previously reported in the literature. By comparing the numerical and experimental data, it is revealed that the proposed method can accurately simulate the failure propagation in notched composite plates at a low computational cost.

关键词： progressive failure notched composite plate Hashin failure criterion macro mechanics approach finite element method

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Risk analysis methods of the water resources system under uncertainty

Zeying GUI,Chenglong ZHANG,Mo Li,Ping GUO

《农业科学与工程前沿（英文）》 2015年第2卷第3期页码 205-215 doi: 10.15302/J-FASE-2015073

摘要： The main characteristic of the water resources system (WRS) is its great complexity and uncertainty, which makes it highly desirable to carry out a risk analysis of the WRS. The natural environmental, social economic conditions as well as limitations of human cognitive ability are possible sources of the uncertainties that need to be taken into account in the risk analysis process. In this paper the inherent stochastic uncertainty and cognitive subjective uncertainty of the WRS are discussed first, from both objective and subjective perspectives. Then the quantitative characterization methods of risk analysis are introduced, including three criteria (reliability, resiliency and vulnerability) and five basic optimization models (the expected risk value model, conditional value at risk model, chance-constrained risk model, minimizing probability of risk events model, and the multi-objective optimization model). Finally, this paper focuses on the various methods of risk analysis under uncertainty, which are summarized as random, fuzzy and mixed methods. A more comprehensive risk analysis methodology for the WRS is proposed based on the comparison of the advantages, disadvantages and applicable conditions of these three methods. This paper provides a decision support of risk analysis for researchers, policy makers and stakeholders of the WRS.

关键词： water resources system evaluation criterion optimization model risk analysis method uncertainty