资源类型

期刊论文 8

年份

2020 1

2019 2

2015 1

2012 1

2010 1

2007 1

2006 1

展开 ︾

关键词

三塔悬索桥 1

关键截面 1

应力幅 1

桥梁 1

桥面铺装 1

正交异性板 1

疲劳 1

疲劳应力分析 1

钢桥面板 1

钢管复合桩;埋床法预制墩台;?75 mm预应力粗钢筋;正交异性钢桥面板;1 860 MPa斜拉索; 减隔震 1

展开 ︾

检索范围:

排序: 展示方式:

Manufacturing and mechanical properties of composite orthotropic Kagome honeycomb using novel modular

Bin NIU, Shijie LI, Rui YANG

《机械工程前沿(英文)》 2020年 第15卷 第3期   页码 484-495 doi: 10.1007/s11465-020-0593-3

摘要: This work deals with manufacturing and analysis of orthotropic composite Kagome honeycomb panels. A novel modular mold is proposed to manufacture carbon fiber reinforced composite Kagome honeycombs. The designed mold can be assembled freely to manufacture Kagome honeycombs with different configuration combinations and can realize easy demolding. Furthermore, two typical fiber placement methods are considered during the fabrication process, from which the more effective fiber placement method is determined. Finally, representative volume element method is used to perform homogenization analysis of the Kagome honeycomb panels and to obtain equivalent in-plane and bending stiffness. Finite element analysis using these equivalent properties is conducted and validated against the experimental results of the manufactured composite Kagome honeycomb panels under different loading cases.

关键词: composite     Kagome honeycomb     manufacturing     placement of fibers     equivalent stiffness    

Structural shifts in the intestinal microbiota of rats treated with cyclosporine A after orthotropic

Junjun Jia, Xinyao Tian, Jianwen Jiang, Zhigang Ren, Haifeng Lu, Ning He, Haiyang Xie, Lin Zhou, Shusen Zheng

《医学前沿(英文)》 2019年 第13卷 第4期   页码 451-460 doi: 10.1007/s11684-018-0675-3

摘要: Understanding the effect of immunosuppressive agents on intestinal microbiota is important to reduce the mortality and morbidity from orthotopic liver transplantation (OLT). We investigated the relationship between the commonly used immunosuppressive agent cyclosporine A (CSA) and the intestinal microbial variation in an OLT model. The rat samples were divided as follows: (1) N group (normal control); (2) I group (isograft LT, Brown Norway [BN] rat to BN); (3) R group (allograft LT, Lewis to BN rat); and (4) CSA group (R group treated with CSA). The intestinal microbiota was assayed by denaturing gradient gel electrophoresis profiles and by using real-time polymerase chain reaction. The liver histopathology and the alanine/aspartate aminotransferase ratio after LT were both ameliorated by CSA. In the CSA group, the numbers of rDNA gene copies of cluster I, cluster XIV, and Enterobacteriaceae decreased, whereas those of increased compared with the R group. Cluster analysis indicated that the samples from the N, I, and CSA groups were clustered, whereas the other clusters contained the samples from the R group. Hence, CSA ameliorates hepatic graft injury and partially restores gut microbiota following LT, and these may benefit hepatic graft rejection.

关键词: microbial community     liver transplantation     immunosuppressive agents     cyclosporine A    

桥面铺装对钢桥面板疲劳应力幅的影响

吴冲,刘海燕,张胜利,崔冰,丁文俊

《中国工程科学》 2010年 第12卷 第7期   页码 39-42

摘要:

钢桥面板厚度小,铺装层的相对刚度较大,钢桥面板疲劳设计时,应该考虑铺装层与钢桥面板的共同作用。假设桥面铺装与顶板没有相对滑移,采用有限元方法探讨了桥面铺装弹性模量和厚度对正交异性钢桥面板疲劳应力幅的影响。

关键词: 桥梁     钢桥面板     桥面铺装     疲劳     应力幅    

Evaluation method of multiaxial low cycle fatigue life for cubic single crystal material

CHEN Jiping, DING Zhiping

《机械工程前沿(英文)》 2007年 第2卷 第3期   页码 278-282 doi: 10.1007/s11465-007-0048-0

摘要: The coupling effect of normal stress and shear stress on orthotropic materials happens when applied loading deflects from the directions of the principal axes of the material coordinate system. By taking account of the coupling effects, formulas of equivalent stress and strain for cubic single crystal materials are cited. Using the equivalent strain and equivalent stress for such material and a variable k, which is introduced to express the effect of asymmetrical cyclic loading on fatigue life, a low cycle fatigue (LCF) life prediction model for such material in multiaxial stress starts is proposed. On the basis of the yield criterion and constitutive model of cubic single crystal materials, a subroutine to calculate the thermo elastic-plastic stress-strain of the material on an ANSYS platform was developed. The cyclic stress-strain of DD3 notched specimens under asymmetrical loading at 680vH was analyzed. Low cycle fatigue test data of the single crystal nickel-based superalloy are used to fit the different parameters of the power law with multiple linear regression analysis. The equivalent stress and strain for a cubic single crystal material as failure parameters have the largest correlation coefficient. A power law exists between k and the failure cycle. The model was validated with LCF test data of CMSX-2 and DD3 single crystal nickel-based superalloys. All the test data fall into the factor of 2.5 for CMSX-2 hollow cylinder specimens and 2.0 scatter band for DD3 notched specimens, respectively.

关键词: orthotropic     regression analysis     crystal material     multiaxial     prediction    

Constitutive Model for an FCC Single-Crystal Material

DING Zhi-ping, LIU Yi-lun, YIN Ze-yong, YANG Zhi-guo, CHENG Xiao-ming

《机械工程前沿(英文)》 2006年 第1卷 第1期   页码 40-47 doi: 10.1007/s11465-005-0012-9

摘要:

Taking into account the effects that the components of tension stresses couple with components of torsion stresses when off-axis loads are applied to orthotropic materials, Hill s yield criterion for plastically orthotropic solids is modified by adding an invariant that is composed of the product item of quadratic components of the deviatoric stress tensor, and a new yield criterion is put forward in terms of the characteristics of the face-centered cubic (FCC) single-crystal material. The correlation of prediction and experiments is very good, and the new criterion is used to predict the yield stresses of an internal single-crystal, Nickel-based superalloy, DD3, which is more accurate than that of Hill s at 760?C. Equivalent stress and strain that adapt to the new criterion are defined. Thinking of the yield function as a plastic potential function from the associated flow rule, the elastic plastic constitutive model for the FCC single-crystal material is constructed, and the corresponding elastic plastic matrix is educed. The new yield criterion and its equivalent stress and strain will be reduced to Von Mises yield criterion and corresponding equivalent stress and strain for isotropic materials.

关键词: orthotropic     Thinking     accurate     prediction     corresponding    

Innovative steel-UHPC composite bridge girders for long-span bridges

Xudong SHAO, Lu DENG, Junhui CAO

《结构与土木工程前沿(英文)》 2019年 第13卷 第4期   页码 981-989 doi: 10.1007/s11709-019-0531-9

摘要: Steel and steel-concrete composite girders are two types of girders commonly used for long-span bridges. However, practice has shown that the two types of girders have some drawbacks. For steel girders, the orthotropic steel deck (OSD) is vulnerable to fatigue cracking and the asphalt overlay is susceptible to damage such as rutting and pot holes. While for steel-concrete composite girders, the concrete deck is generally thick and heavy, and the deck is prone to cracking because of its low tensile strength and high creep. Thus, to improve the serviceability and durability of girders for long-span bridges, three new types of steel-UHPC lightweight composite bridge girders are proposed, where UHPC denotes ultra-high performance concrete. The first two types consist of an OSD and a thin UHPC layer while the third type consists of a steel beam and a UHPC waffle deck. Due to excellent mechanical behaviors and impressive durability of UHPC, the steel-UHPC composite girders have the advantages of light weight, high strength, low creep coefficient, low risk of cracking, and excellent durability, making them competitive alternatives for long-span bridges. To date, the proposed steel-UHPC composite girders have been applied to 14 real bridges in China. It is expected that the application of the new steel-UHPC composite girders on long-span bridges will have a promising future.

关键词: steel-UHPC composite bridge girder     long-span bridge     orthotropic steel deck     fatigue cracking     durability    

随机车辆荷载下三塔悬索桥钢箱梁疲劳关键断面分析

陈策,吉伯海,刘荣

《中国工程科学》 2012年 第14卷 第5期   页码 75-79

摘要:

泰州大桥为世界首座千米级三塔悬索桥,建立泰州大桥的三维全桥模型,通过简化的车辆荷载模型,将随机车流加载于大桥有限元模型上,计算泰州大桥主梁不同位置竖向位移和弯矩的振动响应值,分析车流作用下大桥主梁应力变化最大位置,从而确定主梁的疲劳分析的关键位置。

关键词: 三塔悬索桥     正交异性板     疲劳应力分析     关键截面    

港珠澳大桥设计理念及桥梁创新技术

孟凡超,刘明虎,吴伟胜,张革军,张 梁

《中国工程科学》 2015年 第17卷 第1期   页码 27-35

摘要:

介绍了港珠澳大桥的工程概况、建设目标和总体设计方案,重点阐述了以“大型化、工厂化、标准化、装配化”的设计理念和总体原则指导下,设计采用的新材料、新技术、新工艺、新设备。创新技术的应用,为提高工程品质、确保设计使用寿命提供了坚实基础和有利保障。

关键词: 钢管复合桩;埋床法预制墩台;?75 mm预应力粗钢筋;正交异性钢桥面板;1 860 MPa斜拉索; 减隔震    

标题 作者 时间 类型 操作

Manufacturing and mechanical properties of composite orthotropic Kagome honeycomb using novel modular

Bin NIU, Shijie LI, Rui YANG

期刊论文

Structural shifts in the intestinal microbiota of rats treated with cyclosporine A after orthotropic

Junjun Jia, Xinyao Tian, Jianwen Jiang, Zhigang Ren, Haifeng Lu, Ning He, Haiyang Xie, Lin Zhou, Shusen Zheng

期刊论文

桥面铺装对钢桥面板疲劳应力幅的影响

吴冲,刘海燕,张胜利,崔冰,丁文俊

期刊论文

Evaluation method of multiaxial low cycle fatigue life for cubic single crystal material

CHEN Jiping, DING Zhiping

期刊论文

Constitutive Model for an FCC Single-Crystal Material

DING Zhi-ping, LIU Yi-lun, YIN Ze-yong, YANG Zhi-guo, CHENG Xiao-ming

期刊论文

Innovative steel-UHPC composite bridge girders for long-span bridges

Xudong SHAO, Lu DENG, Junhui CAO

期刊论文

随机车辆荷载下三塔悬索桥钢箱梁疲劳关键断面分析

陈策,吉伯海,刘荣

期刊论文

港珠澳大桥设计理念及桥梁创新技术

孟凡超,刘明虎,吴伟胜,张革军,张 梁

期刊论文