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 23

年份

2022 1

2019 1

2018 2

2017 1

2014 1

2013 4

2012 3

2010 1

2009 2

2008 1

2006 1

2005 3

展开︾

关键词

DX桩 2

悬索桥 2

数值分析 2

Chebyshev多项式 1

三峡升船机 1

三维有限元分析 1

仿真分析 1

体外预应力 1

全过程控制 1

关键技术 1

凸块锚固区 1

北边跨锚侧 1

可拓分类树 1

大体积混凝土 1

天顶仪投点 1

套管空间定位测量 1

安装与线形调整 1

实时监控 1

应力场 1

展开︾

检索范围：

排序：展示方式：

Influence of surface cracking, anchor head profile, and anchor head size on cast-in headed anchors in

《结构与土木工程前沿（英文）》页码 1163-1187 doi: 10.1007/s11709-023-0987-5

摘要： In this study, the concrete cone capacity, concrete cone angle, and load–displacement response of cast-in headed anchors in geopolymer concrete are explored using numerical analyses. The concrete damaged plasticity (CDP) model in ABAQUS is used to simulate the behavior of concrete substrates. The tensile behavior of anchors in geopolymer concrete is compared with that in normal concrete as well as that predicted by the linear fracture mechanics (LFM) and concrete capacity design (CCD) models. The results show that the capacity of the anchors in geopolymer concrete is 30%–40% lower than that in normal concrete. The results also indicate that the CCD model overestimates the capacity of the anchors in geopolymer concrete, whereas the LFM model provides a much more conservative prediction. The extent of the difference between the predictions by the numerical analysis and those of the above prediction models depends on the effective embedment depth of the anchor and the anchor head size. The influence of concrete surface cracking on the capacity of the anchor is shown to depend on the location of the crack and the effective embedment depth. The influence of the anchor head profile on the tensile capacity of the anchors is found to be insignificant.

关键词： cast-in anchor concrete cone capacity geopolymer concrete head size surface crack anchor profile

HTML PDF 收藏

Premature melt solidification during mold filling and its influence on the as-cast structure

M. WU, M. AHMADEIN, A. LUDWIG

《机械工程前沿（英文）》 2018年第13卷第1期页码 53-65 doi: 10.1007/s11465-017-0437-y

摘要：

Premature melt solidification is the solidification of a melt during mold filling. In this study, a numerical model is used to analyze the influence of the pouring process on the premature solidification. The numerical model considers three phases, namely, air, melt, and equiaxed crystals. The crystals are assumed to have originated from the heterogeneous nucleation in the undercooled melt resulting from the first contact of the melt with the cold mold during pouring. The transport of the crystals by the melt flow, in accordance with the so-called “big bang” theory, is considered. The crystals are assumed globular in morphology and capable of growing according to the local constitutional undercooling. These crystals can also be remelted by mixing with the superheated melt. As the modeling results, the evolutionary trends of the number density of the crystals and the volume fraction of the solid crystals in the melt during pouring are presented. The calculated number density of the crystals and the volume fraction of the solid crystals in the melt at the end of pouring are used as the initial conditions for the subsequent solidification simulation of the evolution of the as-cast structure. A five-phase volume-average model for mixed columnar-equiaxed solidification is used for the solidification simulation. An improved agreement between the simulation and experimental results is achieved by considering the effect of premature melt solidification during mold filling. Finally, the influences of pouring parameters, namely, pouring temperature, initial mold temperature, and pouring rate, on the premature melt solidification are discussed.

关键词： premature solidification mold filling as-cast structure modeling

HTML PDF 收藏

Calculation of prestressed anchor segment by 3D infinite element

Yanfen WANG, Hongyang XIE, Yuanhan WANG

《结构与土木工程前沿（英文）》 2009年第3卷第1期页码 63-66 doi: 10.1007/s11709-009-0006-5

摘要： Based on 1D infinite element theory, the coordinate transformation and shape function of 3D point-radiation 4-node infinite elements were derived. They were coupled with 8-node finite elements to compute the compressive deformation of the prestressed anchor segment. The results indicate that when the prestressed force acts on the anchor segment, the stresses and displacements in the rock around the anchor segment are concentrated in the zone center with the anchor axis and are subjected to exponential decay. Therefore, the stresses and the displacement spindles are formed. The calculation results of the infinite element are close to the theoretical results.

关键词： infinite element prestressed anchor couple finite element

HTML PDF 收藏

Propagation characteristics of transient waves in low-strain integrity testing on cast-in-situ concrete

Hanlong LIU, Xuanming DING

《结构与土木工程前沿（英文）》 2009年第3卷第2期页码 240-240 doi: 10.1007/s11709-009-0100-8

HTML PDF 收藏

Dynamic performance of submerged floating tunnel with different mooring styles subjected to anchor cable

《结构与土木工程前沿（英文）》 doi: 10.1007/s11709-023-0932-7

摘要： Submerged floating tunnels (SFTs) are novel structures for transportation across long- and deep-strait regions. Owing to severe wave and current excitation as well as the effects of underwater structures and corrosion, the risk of local anchor cable failure is high, which can result in the progressive failure of the entire structure. In this study, experimental and numerical investigations are conducted to analyze the dynamic behavior of an SFT with different mooring styles under local cable failure. A custom-designed cable failure device and the birth-and-death element method are used to simulate cable failure (i.e., progressive failure) via experiments and numerical simulation, respectively. A physical-scale segmental model of an SFT with different mooring styles under anchor cable failure is developed in this study. A segmental and entire-length mathematical model is developed using the ANSYS program to perform the numerical simulation. The results of the segmental numerical and experimental models indicate good agreement. The dynamic response of an SFT with different mooring styles under cable failure is comprehensively investigated by investigating the effects of key parameters (wave period, buoyant weight ratio, and cable failure mechanism). Moreover, the progressive failure of the SFT under cable failure is investigated via a segment model test and a numerical simulation of its entire length. The present study can serve as a reference for the safer designs of the SFT mooring style.

关键词： dynamic behaviors submerged floating tunnel cable failure mooring style progressive failure

HTML PDF 收藏

Chebyshev多项式在锚链分析中的应用

滕斌,郝春玲,韩凌

《中国工程科学》 2005年第7卷第1期页码 21-26

摘要：

依据水流作用下锚链的数值分析模型，提出了应用Chebyshev多项式拟合建立锚链张力与锚链顶端位置函数关系的近似方法，该锚链函数多项式可方便地用于波浪与锚泊结构物相互作用的实时模拟中。计算中按静水和有流两种情况，应用二维和三维Chebyshev多项式，建立了锚链顶端水平和垂向拉力与锚链顶端水平、垂向位置，及水流速度的函数关系。锚链分析模型采用分段外推－校正方法计算，在无流、均质锚链情况下，计算结果与解析解完全吻合。

关键词：锚链张力锚链位移 Chebyshev多项式

HTML PDF 收藏

Synergistic effects of sodium hypochlorite disinfection and iron-oxidizing bacteria on early corrosion in cast

《环境科学与工程前沿（英文）》 2022年第16卷第6期 doi: 10.1007/s11783-021-1506-3

摘要：

• The early corrosion process in the cast iron pipes was investigated.

关键词： Cast iron pipe corrosion Drinking water distribution systems Chlorine disinfection Iron-oxidizing bacteria Coupling effects

HTML PDF 收藏

Fabrication of layered structure VS anchor in 3D graphene aerogels as a new cathode material for lithium

《能源前沿（英文）》 2019年第13卷第3期页码 597-602 doi: doi:10.1007/s11708-018-0576-9

摘要： VS₄ has gained more and more attention for its high theoretical capacity (449 mAh/g with 3e⁻ transfer) in lithium ion batteries (LIBs). Herein, a layered structure VS₄ anchored in graphene aerogels is prepared and first reported as cathode material for LIBs. VS₄@GAs composite exhibits an exceptional high initial reversible capacity (511 mAh/g), an excellent high-rate capability (191 mAh/g at the 5 C), and an excellent cyclic stability (239 mAh/g after 15 cycles).

关键词： VS₄ graphene aerogels cathode lithium storage

HTML PDF 收藏

基于可拓学的球墨铸铁石墨形态识别

陈智斌,余永权,杨少敏

《中国工程科学》 2005年第7卷第3期页码 84-89

摘要：

根据石墨的形态特征，运用物元分析方法建立起关于石墨形态识别的物元模型，提出了可拓分类树方法，讨论了可拓分类树的构造和实现途径，并将其应用于石墨形态的类型判别；给出了典型的实验结果，并对该方法与现有识别方法作出比较。

关键词：物元模型可拓分类树石墨形态球墨铸铁

HTML PDF 收藏

锚杆关键参数对锚杆重力式海上风机基础承载特性的影响

王尔贝,陈锐,霍宏斌

《中国工程科学》 2014年第16卷第8期页码 69-73

摘要：

针对最近提出的锚杆重力式海上风机基础，采用有限元分析软件ABAQUS研究了锚杆的关键参数对此新型基础承载特性的影响。结果表明：增加锚杆数量可以提高基础的承载力并减小单根锚杆的轴力。但是当锚杆数量增加到一定程度时，会使其间距过小，引起地基中应力的叠加，降低锚杆群的承载效率，因此锚杆数量存在上限。基础承载力几乎随锚杆直径的增加呈线性提高，锚杆直径越大对基础稳定越有利，因此在可行的情况下，应尽可能地选用大直径锚杆。锚杆环直径的增大相当于增大了基础抗倾覆力矩的力臂，因此对弯矩承载力是有利的，但由于锚杆群对地基等效刚度的改变，竖向承载力会随着锚杆环直径的增大而先增后减。设计时要综合考虑各个承载力因素，选用合适的锚杆环直径。

关键词：海上风机重力式基础锚杆三维有限元分析

HTML PDF 收藏

Defect passivation on cast-mono crystalline screen-printed cells

Alison WENHAM,Lihui SONG,Malcolm ABBOTT,Iskra ZAFIROVSKA,Sisi WANG,Brett HALLAM,Catherine CHAN,Allen BARNETT,Stuart WENHAM

《能源前沿（英文）》 2017年第11卷第1期页码 60-66 doi: 10.1007/s11708-016-0443-5

摘要： Cast-mono crystalline silicon wafers contain crystallographic defects, which can severely impact the electrical performance of solar cells. This paper demonstrates that applying hydrogenation processes at moderate temperatures to finished screen print cells can passivate dislocation clusters within the cast-mono crystalline silicon wafers far better than the hydrogenation received during standard commercial firing conditions. Efficiency enhancements of up to 2% absolute are demonstrated on wafers with high dislocation densities. The impact of illumination to manipulate the charge state of hydrogen during annealing is investigated and found to not be significant on the wafers used in this study. This finding is contrary to a previous study on similar wafers that concluded increased H or H from laser illumination was responsible for the further passivation of positively charged dangling bonds within the dislocation clusters.

关键词： silicon solar cell dislocation cast-mono laser hydrogen passivation

HTML PDF 收藏

铸钢粗晶的成因及消除方法的研究

邹安全,邓沛然

《中国工程科学》 2005年第7卷第4期页码 79-82

摘要：

通过对ZG32Cr06铸钢粗晶成因的分析及消除粗晶的工艺性能试验，探讨了粗晶导致铸件断裂的机理。试验证明，由于浇铸温度过高，水爆清砂时开箱过早而产生的粗晶可以用热处理方法消除，同时提出了铸件在浇铸时防止粗晶的措施。

关键词：铸钢粗晶水爆清砂消除方法

HTML PDF 收藏

体外预应力凸块锚固区配筋设计研究

洪浩,童育强,贺志启,刘钊

《中国工程科学》 2013年第15卷第8期页码 95-98

摘要：

混凝土凸块锚固区是体外预应力的一种常见锚固形式，目前尚没有成熟的设计方法。本文通过有限元数值分析，揭示了产生局部拉应力集中的3种作用效应；在此基础上，提出了这3种局部作用效应合拉力的解析计算公式，作为凸块锚固区定量化配筋设计的依据。通过南京长江第四大桥引桥凸块锚固区的设计实践，表明该方法具有良好的实用性。

关键词：凸块锚固区体外预应力配筋设计锚下劈裂悬臂效应锚后牵拉

HTML PDF 收藏

润扬大桥悬索桥北锚碇基础接触应力仿真分析

邵国建,苏静波,胡强

《中国工程科学》 2006年第8卷第6期页码 28-34

摘要：

针对润扬大桥悬索桥北锚碇基础的浇筑施工、运行过程，基于大型有限元分析软件Marc进行二次开发，建立了锚碇基础和土体共同作用的三维有限元仿真计算模型。考虑锚碇基础浇筑过程中地下水位改变引起基底水压力的变化对锚碇基础接触应力分布的影响，对锚碇体浇筑到运行的全过程进行了仿真数值计算，揭示了岩层地基上悬索桥重力式嵌岩锚碇基础接触应力在施工到运行过程中的变化规律。工程实例数值计算结果表明，在不同施工浇筑阶段，尽管锚碇基础不同部位的接触应力呈现出不同的变化特征，北锚碇基础在施工到运行全过程中基础接触应力总体满足设计要求。

关键词：悬索桥锚碇基础接触应力仿真分析

HTML PDF 收藏

DX桩群桩承载性状的数值分析

张清林,陈立宏

《中国工程科学》 2012年第14卷第1期页码 51-59

摘要：

通过数值计算对不同桩间距的DX桩群桩进行了分析研究。结果表明：DX桩的群桩效应随着桩间距的减小而逐渐明显，间距为6倍桩径的群桩极限承载力是间距为3倍桩径的群桩极限承载力的1.32倍；群桩间距由3倍桩径增大为6倍桩径时，群桩效应系数由0.59增大为0.78；群桩间土体沉降的最大值发生在两扩盘中间位置处，且随着桩间距的增大而减小。

关键词： DX桩群桩沉降数值分析