Abstract : simplifying the formula in code for concrete structure design ( gbj10 - 89 ) , we obtaine the appoximate formula of crack width , that is used to the beam of rectangular section in design 文摘:对《混凝土结构设计规范》 ( gbj10 - 89 )中的裂缝宽度计算公式进行化简,得出矩形截面梁裂缝宽度实用计算公式,供工程设计时使用。
Differential arithmetic is utilized to set up the numerical value arithmetic of the diffusion model of circular and rectangular section ; at the same time , the stability of the numerical value arithmetic is analyzed ; 4 利用差分算法,建立了圆形截面以及矩形截面氯离子扩散模型的数值解法,并对数值算法的稳定性进行了分析; 4
The experimental model is a rectangular section of 15 . 2 187mm ~ 2 , which is composed of two aluminum plates . the angles between the internal netted rib turbulators and the flow direction are 45 ? for the one plate and 60 ? for the other , or both 45 ? for two plates . in the experiment , the re numbers changes from 0 . 4 10 ~ 4 1 . 5 10 ~ 5 , rib width - to - pitch are 0 . 25 , 0 . 3 and 0 . 5 , rib width - to - height are 0 . 25 , 0 . 3 and 0 . 5 , the rib height - to - hydraulic diameter ratio is 0 . 246 主要研究了在通道进口截面积(即无肋处的截面积) a为15 . 2 187mm ~ 2 、肋高与通道当量直径之比e / de等于0 . 246 ,实验雷诺数范围在0 . 4 10 ~ 4 1 . 5 10 ~ 5之间的情况下,雷诺数re 、肋向角a 、肋宽与肋高之比t / e和肋宽与肋间距之比t / p等参数对通道强化传热与流动阻力特性的影响。
At first , the experiment carried out by tianjin university has been analysed according to the " nonlinear balance trying calculation " method , and the values of yield load and ultimate load agree with the test result better , and the curve of bending moment - curvature , bending moment - deflection can agree with the results . the second , the simplified formula for evaluation the ultimate flexural capacity of cfrp strengthened rc members is presented according to the three probable failure modes ( compression failure ; cfrp rupture ; crushing of the concrete in compression before yielding of the reinforcing steel ) . it is applicable to both singly and doubly reinforced rectangular sections , as well as flanged sections 首先利用钢筋混凝土非线性平衡试算法对天津大学试验进行了理论分析,所得分析值与试验结果相比,加固梁的屈服荷载、极限荷载能够很好地吻合,弯矩曲率关系曲线及弯矩挠度关系曲线较为吻合;其次,为了满足实际工程的需要,根据碳纤维布加固构件可能发生的三种破坏形态(压区混凝土压碎破坏、碳纤维布拉断破坏以及受拉钢筋尚未屈服时压区混凝土已压碎破坏) ,区别三种钢筋混凝土构件截面形式(单筋矩形截面、双筋矩形截面、 t形截面) ,分别给出了碳纤维布加固混凝土构件抗弯承载力的简化计算公式和适用条件,并进一步探讨了这三种截面形式下进行加固设计和复核的步骤。
Thus , the conclusion is drawn : when the diffusion coefficient of cf is invariable and the diffusion time is under a certain range , the beginning corrosion time of the steel in the corner of the rectangular section is independent of the size of rectangular section ; ( 4 ) through the numerical value calculation of rectangular section , the law is found of the influence on modifying coefficient of rectangular section of the thickness of protection layer of concrete and diameter of the steel and the thickness of cf on the surface of concrete , based on which practical calculating method of beginning corrosion time of the steel in the corner of rectangular section is set up 从而得到结论:在氯离子扩散系数一定的情况下,在一定时间范围内,矩形截面边角区域钢筋的初始锈蚀时间不依赖于矩形截面的截面尺寸; ( 4 )通过矩形截面边角区域钢筋初始锈蚀时间的计算,分析了保护层厚度、钢筋直径、混凝土表面氯离子浓度对修正系数的影响,并在此基础上建立了氯离子侵蚀下矩形截面边角区域钢筋初始锈蚀时间的实用计算方法。
Taking beam with rectangular section as an example , the corresponding analytical solution of beam subjected to cosine distribution pressure is given through constructing the stress function satisfying all boundary conditions and biharmonic equation , which is a base of beam subjected to arbitrary distribution pressure 摘要以矩形截面简支梁为例,通过构造一个满足所有边界条件和双调和方程的应力函数,给出了梁受余弦分布力作用情况下相应的解析解,这为求解梁受任意分布压力作用下解的问题打下了基础。
Many factors regarding the modifying coefficients of circular and rectangular section are analyzed : ( 1 ) it is theoretically proved that the diffusion coefficient of cl - in concrete is dependent of modifying coefficients ; ( 2 ) through analysis of the results of numerical value calculation , it is discovered that the relation between the modifying coefficients and the thickness of protection layer of concrete is linear , from which the function expression of these two variables is gain ; at the same time , the influence on modifying coefficient of the radius of circular section and the thickness of cl - on the surface of concrete ; based on these , practical calculating method of beginning corrosion time of steel of circular section is set up ; ( 3 ) to rectangular section , the diffusion of cf in concrete is two - dimension diffusion 讨论了影响矩形截面以及圆形截面修正系数的因素: ( 1 )从理论上证明了氯离子在混凝土中的扩散系数与修正系数无关; ( 2 )通过圆形截面数值计算结果的分析,发现圆形截面修正系数与保护层厚度基本成线性关系,并建立了二者之间的联系;分析了圆形截面半径、混凝土表面氯离子浓度对修正系数的影响,从而建立了圆形截面钢筋初始锈蚀时间的实用计算方法; ( 3 )在矩形截面氯离子侵蚀下,混凝土处于二维扩散状态。本文通过计算分析,证明二维扩散的影响区域从边角开始向中间逐步扩散,并证明了二维扩散影响区域依赖于氯离子扩散系数与氯离子扩散时间的乘积。
The dissertation mainly has a research on beam shape of concrete transfer floor . the load form of transfer floor is complicated and the stress - strain changes greatly , so the structure design could be divided into the calculations of rectangular sections in bending , incline plane in shearing , and shear wall structure . because transfer floor is an important part in high - rise building , it needs special requests of design and structure 本文以目前广泛使用的梁式钢筋混凝土转换层为研究对象,针对梁式转换层受力复杂,应力应变变化大,重点研究了深梁截面设计法的正截面受弯、斜截面受剪及转换层剪力墙结构的计算,并对转换层结构构造设计进行了分析。
For the american put option which does not have analytical solution , several new numerical algorithms are presented on its pricing , each of them is given finite difference method and finite element method on variables based on individual underlying variable and two underlying variable respectively . for finite element method , bilinear interpolation of rectangular sectioning is adopted 另外,对不存在解析解的美式看跌期权的定价给出了几种新的数值算法,分别对基于单个标的变量和两个标的变量的美式看跌期权定价给出了有限差分法和有限元法,有限元法采用了矩形剖分的双线性插值。
Based on the design code for strengthening concrete structure , using the theory of calculating the flexural capacity and the shear capacity of rc beams with rectangular section strengthened by frp , it is calculated and analysed the flexural capacity and the shear capacity of rc beams strengthened by bfrp sheets or cfrp sheets 摘要基于现行混凝土结构加固设计规范关于粘贴纤维增强复合材料加固法的计算理论,分别对玄武岩纤维布和碳纤维布加固钢筋混凝土梁的正截面受弯承载力、斜截面受剪承载力进行计算分析,以探讨玄武岩纤维布对钢筋混凝土梁的加固效果。