资源类型

期刊论文 112

年份

2023 10

2022 10

2021 9

2020 9

2019 13

2018 2

2017 5

2016 3

2015 4

2014 9

2013 1

2012 2

2011 5

2010 7

2009 4

2008 4

2007 4

2006 3

2005 1

2004 1

展开 ︾

关键词

(GaxIn1−x)2O3薄膜；带隙可调谐；磁控溅射 1

LoRa 1

NB-IoT 1

S频段 1

V形坑 1

WiFi多频天线 1

介质谐振器天线 1

优化 1

位移与滑动形式 1

低衰耗光纤 1

体积应变 1

光纤带 1

光纤带状光缆 1

光纤通信 1

共口径；平面天线；高隔离度；基片集成波导 1

内衬混凝土 1

剪切和弯曲的共同作用 1

剪切带 1

剪切应力 1

展开 ︾

检索范围：

排序： 展示方式：

Review of the damage mechanism in wind turbine gearbox bearings under rolling contact fatigue

Yun-Shuai SU, Shu-Rong YU, Shu-Xin LI, Yan-Ni HE

《机械工程前沿（英文）》 2019年 第14卷 第4期   页码 434-441 doi: 10.1007/s11465-018-0474-1

摘要： Wind turbine gearbox bearings fail with the service life is much shorter than the designed life. Gearbox bearings are subjected to rolling contact fatigue (RCF) and they are observed to fail due to axial cracking, surface flaking, and the formation of white etching areas (WEAs). The current study reviewed these three typical failure modes. The underlying dominant mechanisms were discussed with emphasis on the formation mechanism of WEAs. Although numerous studies have been carried out, the formation of WEAs remains unclear. The prevailing mechanism of the rubbing of crack faces that generates WEAs was questioned by the authors. WEAs were compared with adiabatic shear bands (ASBs) generated in the high strain rate deformation in terms of microstructural compositions, grain refinement, and formation mechanism. Results indicate that a number of similarities exist between them. However, substantial evidence is required to verify whether or not WEAs and ASBs are the same matters.

关键词： rolling contact fatigue (RCF)     white etching area (WEA)     white etching crack (WEC)     adiabatic shear band (ASB)    

HTML PDF 收藏

Simulation on refrigerant flow in adiabatic capillary tube

WANG Meixia, LIU Cunfang, ZHOU Qiangtai

《机械工程前沿（英文）》 2008年 第3卷 第3期   页码 332-336 doi: 10.1007/s11465-008-0054-x

摘要： This paper proposes a new mathematical model to calculate flow characteristics of the adiabatic capillary tube, which is aimed at solving problems existing in some earlier models. The Stocker’s model was modified with consideration of various effects due to sub-cooling, area concentration, and rolling diameter. The new model can be used not only for R22, but also for its substitutes such as R410A and R407C. A comparison of simulation results of the modified model with those in literature showed that the errors are within 10%. The flow characteristics are finally analyzed.

关键词： mathematical     diameter     literature     sub-cooling     adiabatic capillary    

HTML PDF 收藏

扩容角对圆形巷道岩爆过程的影响

王学滨,潘一山,张智慧

《中国工程科学》 2010年 第12卷 第2期   页码 40-46

摘要：

利用FLAC模拟了不同扩容角时圆形巷道的岩爆过程。为了模拟巷道开挖，利用编写的FISH函数删除巷道内部的单元。岩石服从莫尔库仑剪破坏与拉破坏复合的破坏准则，破坏之后呈现应变软化—理想塑性行为。文章的模拟分为3步：首先，将静水压力施加在模型上，直到达到静力平衡状态；然后，利用编写的FISH函数，开挖巷道；最后，计算重新开始，直到达到静力平衡状态。模拟结果表明，随着扩容角的增加，剪切带变宽，岩爆坑变深，破坏单元数目增多，破坏区变大。当扩容角较低时，高剪切应变集中于“狗耳”形岩爆坑位置，剪切带与巷道周边切线之间的夹角较大；当扩容角较高时，高剪切应变集中于巷道周边的一些位置上，剪切带与巷道周边切线之间的夹角较小。该研究结果与Roscoe，Arthur理论相符。

关键词： 扩容角     圆形巷道     岩爆     剪切带     V形坑     剪切应变     体积应变    

HTML PDF 收藏

装甲用镁合金抗弹性能表征体系探讨

才鸿年,谭成文,王富耻,陈志勇

《中国工程科学》 2006年 第8卷 第2期   页码 30-33

摘要：

介绍了高应变率载荷条件下镁合金的吸能特性及变形特征；论述了对镁合金抗弹性能有重要影响的动态强度、高应变率能量吸收率、高应变率变形断裂特征和动态强度等科学问题；就镁合金在装甲领域的应用研究做了初步探讨。

关键词： 能量吸收率     绝热剪切变形局部化     动态强度     动态硬度    

HTML PDF 收藏

Calculations of narrow-band transimissities and the Planck mean absorption coefficients of real gasesusing line-by-line and statistical narrow-band models

Huaqiang CHU, Mingyan GU, Huaichun ZHOU, Fengshan LIU

《能源前沿（英文）》 2014年 第8卷 第1期   页码 41-48 doi: 10.1007/s11708-013-0292-4

摘要： Narrow-band transmissivities in the spectral range of 150 to 9300 cm and at a uniform resolution of 25 cm were calculated using the statistical narrow-band (SNB) model with the band parameters of Soufiani and Taine, the more recent parameters of André and Vaillon, and the line-by-line (LBL) method along with the HITEMP-2010 spectroscopic database. Calculations of narrow-band transmissivity were conducted for gas columns of different lengths and containing different isothermal and non-isothermal CO -H O-N mixtures at 1 atm. Narrow-band transmissivities calculated by the SNB model are in large relative error at many bands. The more recent SNB model parameters of André and Vaillon are more accurate than the earlier parameters of Soufiani and Taine. The Planck mean absorption coefficients of CO , H O, CO, and CH in the temperature range of 300 to 2500 K were calculated using the LBL method and different versions of the high resolution transmission (HITRAN) and high-temperature spectroscopic absorption parameters (HITEMP) spectroscopic databases. The SNB model was also used to calculate the Planck mean absorption coefficients of these four radiating gases. The LBL results of the Planck mean absorption coefficient were compared with the classical results of Tien and those from the SNB model.

关键词： transimissity     HITEMP     HITRAN     Planck mean absorption coefficients    

HTML PDF 收藏

国外光纤光纤带和带状光缆技术的最新发展

刘良炎

《中国工程科学》 2001年 第3卷 第9期   页码 86-94

摘要：

综合介绍了近年国外关于低衰耗的色散补偿光纤，非零色散位移光纤，用于恶劣环境的碳涂覆和氮化硅涂覆光纤的研究；光纤带制造技术包括光纤带的结构、涂层、性能、生产工艺，大芯数光纤带状光缆包括层绞式松管、中心松管式、骨架式、干缆芯带状光缆的设计制造技术的最新进展。

关键词： 光纤通信     低衰耗光纤     光纤带     光纤带状光缆    

HTML PDF 收藏

Level set band method: A combination of density-based and level set methods for the topology optimization

Peng WEI, Wenwen WANG, Yang YANG, Michael Yu WANG

《机械工程前沿（英文）》 2020年 第15卷 第3期   页码 390-405 doi: 10.1007/s11465-020-0588-0

摘要： The level set method (LSM), which is transplanted from the computer graphics field, has been successfully introduced into the structural topology optimization field for about two decades, but it still has not been widely applied to practical engineering problems as density-based methods do. One of the reasons is that it acts as a boundary evolution algorithm, which is not as flexible as density-based methods at controlling topology changes. In this study, a level set band method is proposed to overcome this drawback in handling topology changes in the level set framework. This scheme is proposed to improve the continuity of objective and constraint functions by incorporating one parameter, namely, level set band, to seamlessly combine LSM and density-based method to utilize their advantages. The proposed method demonstrates a flexible topology change by applying a certain size of the level set band and can converge to a clear boundary representation methodology. The method is easy to implement for improving existing LSMs and does not require the introduction of penalization or filtering factors that are prone to numerical issues. Several 2D and 3D numerical examples of compliance minimization problems are studied to illustrate the effects of the proposed method.

关键词： level set method     topology optimization     density-based method     level set band    

HTML PDF 收藏

Modeling of shear walls using finite shear connector elements based on continuum plasticity

Ulf Arne GIRHAMMAR, Per Johan GUSTAFSSON, Bo KÄLLSNER

《结构与土木工程前沿（英文）》 2017年 第11卷 第2期   页码 143-157 doi: 10.1007/s11709-016-0377-3

摘要： Light-frame timber buildings are often stabilized against lateral loads by using diaphragm action of roofs, floors and walls. The mechanical behavior of the sheathing-to-framing joints has a significant impact on the structural performance of shear walls. Most sheathing-to-framing joints show nonlinear load-displacement characteristics with plastic behavior. This paper is focused on the finite element modeling of shear walls. The purpose is to present a new shear connector element based on the theory of continuum plasticity. The incremental load-displacement relationship is derived based on the elastic-plastic stiffness tensor including the elastic stiffness tensor, the plastic modulus, a function representing the yield criterion and a hardening rule, and function representing the plastic potential. The plastic properties are determined from experimental results obtained from testing actual connections. Load-displacement curves for shear walls are calculated using the shear connector model and they are compared with experimental and other computational results. Also, the ultimate horizontal load-carrying capacity is compared to results obtained by an analytical plastic design method. Good agreements are found.

关键词： shear walls     wall diaphragms     finite element modelling     plastic shear connector     analytical modelling     experimental comparison    

HTML PDF 收藏

Nonlinear numerical simulation of punching shear behavior of reinforced concrete flat slabs with shear-heads

Dan V. BOMPA, Ahmed Y. ELGHAZOULI

《结构与土木工程前沿（英文）》 2020年 第14卷 第2期   页码 331-356 doi: 10.1007/s11709-019-0596-5

摘要： This paper examines the structural response of reinforced concrete flat slabs, provided with fully-embedded shear-heads, through detailed three-dimensional nonlinear numerical simulations and parametric assessments using concrete damage plasticity models. Validations of the adopted nonlinear finite element procedures are carried out against experimental results from three test series. After gaining confidence in the ability of the numerical models to predict closely the full inelastic response and failure modes, numerical investigations are carried out in order to examine the influence of key material and geometric parameters. The results of these numerical assessments enable the identification of three modes of failure as a function of the interaction between the shear-head and surrounding concrete. Based on the findings, coupled with results from previous studies, analytical models are proposed for predicting the rotational response as well as the ultimate strength of such slab systems. Practical recommendations are also provided for the design of shear-heads in RC slabs, including the embedment length and section size. The analytical expressions proposed in this paper, based on a wide-ranging parametric assessment, are shown to offer a more reliable design approach in comparison with existing methods for all types of shear-heads, and are suitable for direct practical application.

关键词： non-linear numerical modelling     concrete damage plasticity     RC flat slabs     shear-heads     punching shear    

HTML PDF 收藏

Behaviour of self-centring shear walls——A state of the art review

《结构与土木工程前沿（英文）》 2023年 第17卷 第1期   页码 53-77 doi: 10.1007/s11709-022-0850-0

摘要： The application of unbonded post-tensioning (PT) in structural walls has led to the development of advanced self-centring (rocking) shear wall systems that has significant advantages, including accelerated construction due to the incorporation of prefabricated elements and segmental construction for different materials (e.g., concrete, masonry, and timber), reduced residual drifts, and little damage upon extreme seismic and wind loads. Concrete, masonry, and timber are often used for the construction of unbonded PT structural wall systems. Despite extensive research since the 1980s, there are no well-established design guidelines available on the shear wall configuration with the required energy dissipation system, joint’s locations and acceptance criteria for shear sliding, confinement, seismic performance factors, PT loss, PT force range and residual drifts of shear walls subjected to lateral loads. In this research a comprehensive state-of-the-art literature review was performed on self-centring shear wall system. An extensive study was carried out to collect a database of 100 concrete, masonry, and self-centring shear wall tests from the literature. The established database was then used to review shear walls’ configurations, material, and components to benchmark requirements applicable for design purposes. The behaviour of concrete, masonry and timber shear walls were compared and critically analysed. The general behaviour, force-displacement performance of the walls, ductility, and seismic response factors, were critically reviewed and analysed for different self-centring wall systems to understand the effect of different parameters including configurations of the walls, material used for construction of the wall (concrete, masonry, timber) and axial stress ratio. The outcome of this research can be used to better understand the behaviour of self-centring wall system in order to develop design guidelines for such walls.

关键词： self-centring shear walls     rocking walls     energy dissipation     seismic performance factors     PT loss     residual drift    

HTML PDF 收藏

Prediction of the shear wave velocity

Amoroso SARA

《结构与土木工程前沿（英文）》 2014年 第8卷 第1期   页码 83-92 doi: 10.1007/s11709-013-0234-6

摘要： The paper examines the correlations to obtain rough estimates of the shear wave velocity from non-seismic dilatometer tests (DMT) and cone penetration tests (CPT). While the direct measurement of is obviously preferable, these correlations may turn out useful in various circumstances. The experimental results at six international research sites suggest that the DMT predictions of from the parameters (material index), (horizontal stress index), (constrained modulus) are more reliable and consistent than the CPT predictions from (cone resistance), presumably because of the availability, by DMT, of the stress history index .

关键词： horizontal stress index     shear wave velocity     flat dilatometer test     cone penetration test    

HTML PDF 收藏

On braced trapezoidal corrugated steel shear panels: An experimental and numerical study

《结构与土木工程前沿（英文）》 2023年 第17卷 第3期   页码 396-410 doi: 10.1007/s11709-023-0934-5

摘要： In this study, a new system consisting of a combination of braces and steel infill panels called the braced corrugated steel shear panel (BCSSP) is presented. To obtain the hysteretic behavior of the proposed system, the quasi-static cyclic performances of two experimental specimens were first evaluated. The finite element modeling method was then verified based on the obtained experimental results. Additional numerical evaluations were carried out to investigate the effects of different parameters on the system. Subsequently, a relationship was established to estimate the buckling shear strength of the system without considering residual stresses. The results obtained from the parametric study indicate that the corrugated steel shear panel (CSSP) with the specifications of a = 30 mm, t = 2 mm, and θ = 90° had the highest energy dissipation capacity and ultimate strength while the CSSP with the specifications of a = 30 mm, t = 2 mm, and θ = 30° had the highest initial stiffness. It can thus be concluded that the latter CSSP has the best structural performance and that increasing the number of corrugations, corrugation angle, and plate thickness and decreasing the sub-panel width generally enhance the performance of CSSPs in terms of the stability of their hysteretic behaviors.

关键词： trapezoidal corrugated plate     steel shear panel     braced steel shear panel     experimental study     buckling resistance.    

HTML PDF 收藏

between office workers’ staying and workstation attributes in a non-territorial office using ultra wide band

Xinnan ZHANG, Takashi IZATO, Junzo MUNENOTO, Daisuke MATSUSHITA, Tetsu YOSHIDA

《结构与土木工程前沿（英文）》 2010年 第4卷 第4期   页码 438-449 doi: 10.1007/s11709-010-0076-4

摘要： This paper investigates the staying and moving characteristics of office workers in a non-territorial office using an ultra wide band (UWB) impulse radio sensor network. The differences between office workers’ staying and moving are clarified according to the individual workstation type that they select. The study determines the characteristics of each type of workstation. By clarifying office workers’ preference for staying and moving with regard to individual workstation types and office worker post, the reasons why office workers in different posts tended to select different types of workstations were revealed. Specifically, leaders tended to select workstations at the “inner meeting corner side” most frequently, as they had a greater need to stay in other areas. In contrast, ordinary staff needed to visit office workers in other areas less often, and as such, they tended to select individual workstations at the “middle meeting corner side.” Barring this, they tended to select individual workstations at the “middle corridor side” or “outer-meeting corner side.” Temporary staff members had little need to visit or stay at other places so they tended to select individual workstations at the “window side,” which is seldom visited or stayed at by other office workers and they could be disturbed less often from their solo work.

关键词： workplace     non-territorial office     staying behavior     ultra wide band (UWB)     sensor network    

HTML PDF 收藏

Fluorene-based narrow-band-gap copolymers for red light-emitting diodes and bulk heterojunction photovoltaic

SUN Mingliang, WANG Li, XIA Yangjun, DU Bin, LIU Ransheng, CAO Yong

《化学科学与工程前沿（英文）》 2008年 第2卷 第3期   页码 257-264 doi: 10.1007/s11705-008-0052-x

摘要： A series of narrow band-gap conjugated copolymers (PFO-DDQ) derived from 9,9-dioctylfluorene (DOF) and 2,3-dimethyl-5,8-dithien-2-yl-quinoxalines (DDQ) is prepared by the palladium-catalyzed Suzuki coupling reaction with the molar feed ratio of DDQ at around 1%, 5%, 15%, 30% and 50%, respectively. The obtained polymers are readily soluble in common organic solvents. The solutions and the thin solid films of the copolymers absorb light from 300–590 nm with two absorbance peaks at around 380 and 490 nm. The intensity of 490 nm peak increases with the increasing DDQ content in the polymers. Efficient energy transfer due to exciton trapping on narrow-band-gap DDQ sites has been observed. The PL emission consists exclusively of DDQ unit emission at around 591–643 nm depending on the DDQ content in solid film. The EL emission peaks are red-shifted from 580 nm for PFO-DDQ1 to 635 nm for PFO-DDQ50. The highest external quantum efficiency achieved with the device configuration ITO/PEDOT/PVK/PFO-DDQ15/Ba/Al is 1.33% with a luminous efficiency 1.54 cd/A. Bulk heterojunction photovoltaic cells fabricated from composite films of PFO-DDQ30 copolymer and [6,6]-phenyl C butyric acid methyl ester (PCBM) as electron donor and electron acceptor, respectively in device configuration: ITO/PEDOT:PSS/PFO-DDQ30:PCBM/PFPNBr/Al shows power conversion efficiencies of 1.18% with open-circuit voltage () of 0.90 V and short-circuit current density () of 2.66 mA/cm under an AM1.5 solar simulator (100 mW/cm). The photocurrent response wavelengths of the PVCs based on PFO-DDQ30/PCBM blends covers 300–700 nm. This indicates that these kinds of low band-gap polymers are promising candidates for polymeric solar cells and red light-emitting diodes.

关键词： simulator     Efficient     band-gap     PFO-DDQ50     intensity    

HTML PDF 收藏

Experimental study on shear behavior of reinforced concrete beams with web horizontal reinforcement

Dong XU,Yu ZHAO,Chao LIU

《结构与土木工程前沿（英文）》 2014年 第8卷 第4期   页码 325-336 doi: 10.1007/s11709-014-0080-1

摘要： In determining the shear capacity of reinforced concrete beams, current codes do not provide any calculation method to evaluate the influence of web horizontal reinforcement, although they exist as structural reinforcements (or skin reinforcement). The present paper comprises results of 11 reinforced concrete beams in an effort to investigate the influence of web horizontal reinforcement on the shear behavior of reinforced concrete beams. The primary design variables are the shear-span-depth ratio, different reinforcement ratio of stirrups and web horizontal reinforcement. Influence of web horizontal reinforcement on crack patterns and failure mode was studied. It was found that web horizontal reinforcement can increase the shear capacity of the beams and restrain growth of inclined cracks effectively. Test results are very valuable, as very few references of shear tests can be found focusing on the effect of web horizontal reinforcement on the shear capacity of the beams.

关键词： reinforced concrete beam     shear strength     web horizontal reinforcement     experiments    

HTML PDF 收藏

标题 作者 时间 类型 操作

Review of the damage mechanism in wind turbine gearbox bearings under rolling contact fatigue

Yun-Shuai SU, Shu-Rong YU, Shu-Xin LI, Yan-Ni HE

期刊论文

Simulation on refrigerant flow in adiabatic capillary tube

WANG Meixia, LIU Cunfang, ZHOU Qiangtai

期刊论文

扩容角对圆形巷道岩爆过程的影响

王学滨,潘一山,张智慧

期刊论文

装甲用镁合金抗弹性能表征体系探讨

才鸿年,谭成文,王富耻,陈志勇

期刊论文

Calculations of narrow-band transimissities and the Planck mean absorption coefficients of real gasesusing line-by-line and statistical narrow-band models

Huaqiang CHU, Mingyan GU, Huaichun ZHOU, Fengshan LIU

期刊论文

国外光纤光纤带和带状光缆技术的最新发展

刘良炎

期刊论文

Level set band method: A combination of density-based and level set methods for the topology optimization

Peng WEI, Wenwen WANG, Yang YANG, Michael Yu WANG

期刊论文

Modeling of shear walls using finite shear connector elements based on continuum plasticity

Ulf Arne GIRHAMMAR, Per Johan GUSTAFSSON, Bo KÄLLSNER

期刊论文

Nonlinear numerical simulation of punching shear behavior of reinforced concrete flat slabs with shear-heads

Dan V. BOMPA, Ahmed Y. ELGHAZOULI

期刊论文

Behaviour of self-centring shear walls——A state of the art review

期刊论文

Prediction of the shear wave velocity

Amoroso SARA

期刊论文

On braced trapezoidal corrugated steel shear panels: An experimental and numerical study

期刊论文

between office workers’ staying and workstation attributes in a non-territorial office using ultra wide band

Xinnan ZHANG, Takashi IZATO, Junzo MUNENOTO, Daisuke MATSUSHITA, Tetsu YOSHIDA

期刊论文

Fluorene-based narrow-band-gap copolymers for red light-emitting diodes and bulk heterojunction photovoltaic

SUN Mingliang, WANG Li, XIA Yangjun, DU Bin, LIU Ransheng, CAO Yong

期刊论文

Experimental study on shear behavior of reinforced concrete beams with web horizontal reinforcement

Dong XU,Yu ZHAO,Chao LIU

期刊论文