不同配筋组合对钢筋混凝土梁M-φ曲线的影响

以钢筋混凝土梁为研究对象,基于平截面假定通过编制非线性计算程序,计算分析了不同配筋率下单筋钢筋混凝土梁和相同受拉钢筋配筋率下,不同数量受压钢筋的钢筋混凝土梁截面的M-φ曲线。讨论了配筋率和受压钢筋配置对钢筋混凝土梁延性及承载力的影响。     

受压区侧面粘贴钢板的钢筋混凝土梁短期刚度研究

对受压区侧面粘钢混凝土梁进行了静力试验,试验中测量了不同集中荷载作用下的钢筋混凝土梁在不同配筋率、不同粘钢截面面积时的跨中挠度。考虑粘贴钢板的作用,将受压区粘贴的钢板换算成混凝土,得到一个T形截面,给出了考虑粘贴钢板作用的混凝土梁短期刚度计算方法。讨论了集中荷载、配筋率和粘钢截面面积等因素对受压区侧面粘贴钢板的钢筋混凝土梁短期刚度的影响。     

钢筋钢纤维混凝土深梁受剪承载力的试验研究

通过16根加入钢纤维的钢筋混凝土深梁的试验研究,探讨钢纤维体积率、剪跨比、纵筋配筋率等因素对钢筋钢纤维混凝土深梁斜截面受剪承载力的影响,提出了与钢筋混凝土深梁相衔接的钢筋钢纤维混凝土深梁斜截面受剪承载力的统一计算方法。     

四面受火后钢筋混凝土柱的可靠性分析

引入高温后混凝土和钢筋强度折减系数公式,建立了火灾后钢筋混凝土柱的抗力模型和极限状态方程,利用改进的一次二阶矩法计算了不同温度作用后当钢筋混凝土柱承受原设计荷载时的可靠性指标.算例分析表明,不同受火时间对钢筋混凝土轴心受压柱的可靠性有很大的影响,在计算时应给予考虑.分析了柱的截面尺寸、长细比、钢筋和混凝土的强度、配筋率、防火保护层厚度等参数对受火后钢筋混凝土柱可靠性指标的影响.     

玻璃纤维布加固的钢筋混凝土梁延性分析

为了确定玻璃纤维布加固的钢筋混凝土梁延性降低的程度,进行了9根玻璃纤维布加固的钢筋混凝土梁和3根对比梁的试验研究.试验中考虑了混凝土立方体抗压强度、加固量、剪跨比和纵向受拉钢筋配筋率4个变化参数.试验结果表明,加固量、剪跨比、配筋率对加固梁的延性影响显著.根据试验结果,建立了加固梁截面延性分析的试验方法,提出了玻璃纤维布加固钢筋混凝土梁延性折减系数,给出了折减系数的统计值.在钢筋混凝土梁延性分析的基础上,根据不同的破坏形态建立了玻璃纤维布加固钢筋混凝土梁延性计算方法,分析了影响延性的主要因素.     

不同配筋形式矩形截面钢筋混凝土梁的弯曲性能及损伤机制的试验研究

采用四种不同配筋率和两种不同配筋形式,进行了8根钢筋混凝土梁的四点弯曲试验,探究了不同配筋率和配筋形式下钢筋混凝土梁的弯曲性能及损伤机制.试验结果表明,钢筋与混凝土粘结面积更大的配筋形式可以增加试验梁的平均裂缝密度,降低裂缝宽度,让裂缝发展导致的刚度衰减更为均匀.相同配筋率条件下粘结面积更大的配筋形式可以大幅减小试验梁破坏时的跨中挠度,但对于较高配筋率的试验梁,过高的粘结应力可能产生脆性的斜截面破坏.随着配筋率的增长,梁抗弯极限荷载明显提高,剪跨区的斜裂缝发展逐渐占据主导.     

不锈钢钢筋等截面替代RC梁撞击力学性能试验研究

利用不锈钢钢筋等截面替代普通钢筋混凝土梁中的受力钢筋解决海洋环境中钢筋腐蚀等问题,采用国内先进的超高重型落锤冲击试验机系统对六根钢筋混凝土梁进行竖向抗冲击试验,采集撞击过程中的冲击作用力、试件测点的位移和应变,并进行分析.结果表明:(1)配筋率较小时(0.21%～0.58%),不锈钢钢筋等截面替代普通钢筋后能有效提高梁整体刚度及弹性恢复能力,降低结构变形,可采用不锈钢钢筋等截面替代普通钢筋解决钢筋腐蚀问题;(2)配筋率较大时(1.04%～2.20%),不锈钢钢筋等截面替代普通钢筋后延性较差,特别是冲击能量较高时,脆性性质更加明显.     

长期受弯构件应力应变分布及变形规律研究

通过全面考虑混凝土徐变收缩、裂缝影响及应力重分布变化过程,推导了适于不同应力分布条件下钢筋混凝土受弯构件截面长期应力应变分布规律的计算方法.提出了钢筋混凝土构件收缩翘曲变形影响系数曲线及曲率计算公式,并建立了分析预测受弯构件初始及长期总变形的通用分析方法.考虑截面非线性应力分布曲线,对各类受弯构件长期徐变收缩效应及变形进行分析,通过了试验验证.研究归纳了配筋率、截面尺寸等影响受弯构件长期挠度变化规律的主要因素.分析表明,钢筋能有效约束受弯构件长期徐变变形,而收缩翘曲变形大小及方向则主要取决于拉、压钢筋配筋率比值;在同等的初始抗弯刚度或截面积条件下,宽扁梁长期变形增长较普通梁显著.     

增大截面法加固钢筋混凝土构件的正截面承载力研究

为了研究增大截面法加固钢筋混凝土偏心受压构件的正截面承载力,采用围套加固法和双侧加固法对不同截面尺寸的偏心受压构件进行承载力试验.应用ABAQUS软件对钢筋混凝土偏压构件的加载过程进行模拟.将实测结果、有限元计算结果与加固规范计算值进行对比.结果表明:实测值、有限元计算结果与《公路桥梁加固设计规范》计算值吻合良好;《混凝土结构加固设计规范》对于加固后大偏心受压构件新增纵向钢筋强度折减系数的选取较为准确,而对于小偏心受压构件的折减系数的选取偏于不安全,建议该折减系数的合理取值为0.8.     

HPF加固RC足尺梁二次受力抗弯试验研究

对4根高性能复合砂浆钢筋网加固的钢筋混凝土足尺梁进行了正截面抗弯二次受力试验研究,通过与另4根同配置未加固钢筋混凝土梁的试验结果对比,研究了原截面纵向配筋率对加固梁抗弯承载力和截面刚度的影响．试验采用三面U型加固形式,量测试验梁裂缝分布形态、荷载-挠度曲线、钢筋应变发展规律等．试验表明复合砂浆钢筋网薄层加固是一种有效的加固方法,能够显著地提高钢筋混凝土梁的抗弯承载力、截面刚度以及抗裂性能．     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with