隨時間變化的鋼筋混凝土阻力分析外文翻譯可提供完整設(shè)計圖紙

1、2014屆 分 類 號: 單位代碼:10452外 文 翻 譯姓 名 學(xué) 號 年 級 2012 專 業(yè) 土木工程 系（院） 建筑學(xué)院 指導(dǎo)教師 2014年4月30日Change over time of the reinforced concrete resistance analysis Abstract :The analysis method on random time dependence of reinforced concrete material is introduced , the effect mechanism on reinforced concrete are dis

2、cussed , and the random time dependence resistance of reinforced concrete is studied. Furthermore , the corrosion of steel bar in reinforced concrete structures is analyzed. A practical statistical method of evaluating the random time dependent resistance , which includes material , structural size

3、and calculation influence , is also established. In addition , an example of predicting random time dependent resistance of reinforced concrete structural element is given.Key words: change over time; concrete; resistance analysis 1. Introduce:For reinforced concrete materials is applicable to many

4、places, and cheap, so it in civil engineering is a very useful materials. Therefore, the material a lot of be used. However, the traditional architectural structure design and reinforced concrete materials research and little note reinforced concrete intensity and time, especially the relationship b

5、etween the different role in material effect is almost not study. Until recently, some of the research in building construction to involve the problem - about reinforced the coagu-flocculation intensity and time of correlation. Has done about reinforced concrete column the failure probability of res

6、earch suggests that low intensity failure probability of reinforced concrete column below accidental load probability. And the calculation method has been applied to the time -varying probability calculation. Low intensity and Liu 4 concrete structure endurance in the research on the role that the d

7、estruction of acceleration. And Lu 6 have discusses the corrosion of reinforcement. Generally speaking, rely on different factors of reinforced concrete resistance decreased greatly. The safety of concrete structure in check, basic theory for reinforced concrete durability analysis provides Suggesti

8、ons. Research change from time to time of the nature of the reinforced concrete structures is necessary.2. Influence factors of reinforced concrete mechanismMany factors on reinforced concrete resistance are influenced. In water area exists more than 50 different chemical corrosion element, and the

9、water in them and work up regulatory role. Get a related reinforced concrete model the practical method is a kind of multi-factor understand method. Usually, for a single factor, many results only considering concrete thickness of carbide carbonation, with the following formula can be said: Can writ

10、e for: D (t) = K t (1) Type of D (t), K and t separately for thickness, speed coefficient and carbonization time. So far, although there are many model was applied to the steel, fatigue damage fracture, but havent everyone recognized conclusion exists. Generally speaking, can reduce the resistance o

11、f reinforced concrete of the variable geometry size are reinforced, circumjacent environment condition and change from time to times resistance, etc. Obviously, reinforced concrete resistance changes yes a random process, or a series of materials () function and structure variables interaction. Rein

12、forced concrete in the air called carbide neutralization reaction. It is in the air with the composite reinforced concrete of CO2 and slow the process and basic materials. In the air completely carbonization close-grained in reinforced concrete cover takes decades of time, but the carbonization of c

13、oncrete as long as not close-grained several years. If the thin carbonization material content is higher, the reinforced concrete strength will fall and the structure of the carbonation processes cross-sectional will accelerate narrowing. The carbonation can cause basicity fall and steel corrosion.

14、Rebar surface corrosion of reinforcement is the iron constantly lose electronic then in soluble in water, again in aerobic conditions react with water. So, consumption of several times time unpolluted materials. So can make produce concrete cover cracks, and reinforced direction along the lower the

15、rapping between reinforcement and concrete reinforced concrete structures, causing the loss of carrying capacity. Recent studies show that the most serious corrosion is reinforced 15mm place protective carbide. On the other hand, because do not perfect surface and the cracks in the concrete, corrosi

16、on on the start time may come early, and the corrosion rate may also greatly improved. When reinforced stress to less than its yield point, the failure rate is fixed. But when reinforced stress was beyond the yield point will increase rate of destruction several times. The latter is known as stress

17、destruction, it is the embodiment of the brittle and dangerous. The corrosion of steel reinforcement reduces the pressure area, destroy the effectiveness of cohesion and lower structure. The air corrosion and all the liquid of reinforced concrete will have a huge impact. They will cause corrosion of

18、 steel and concrete, concrete cover thickness decreases, finally accelerate reinforced corrosion. When a structure is bear live load, fatigue damage of reinforced concrete structures, causing the ultimate strength and stiffness reduction and make it produced and expand crack. Usually fatigue damage

19、can be divided into fixed and the stochastic damage, the former is used to decide load cycle, while the latter relative to any materials and load is concerned. In addition to the above, and many other factors outside of its have influence. For example temperature (including temperature height, chang

20、e cycle, cold, humidity (including dry wet cycle), the attenuation and load. Load of the amplitude can make the lowering of reinforced concrete structures. 3. Any time the correlation analysisBelong to this situation structure of random variables are independent of each other, and think that changes

21、 with time for characteristics of the materials to random time dependent function characteristics of reinforced concrete can use the following formula to say: Type: this random variable structure materials and test pointed out the difference of material properties;Is construction test materials prop

22、erties, is the difference between the test materials coefficient of random variable.According to the statistics theory, the mean and standard deviation coefficient since. （3） Type says average:Says stochastic process standards since deviation coefficient,And espectively is test material properties o

23、f the mean and standard deviation coefficient and the random variables. Similarly, any analytical model with the most similar to study suggest that any changes with time of reinforced concrete structures of geometric parameters and calculating methods. Similarly, a similar analysis model of the chan

24、ging with time of reinforced concrete structure most geometric parameters and calculation method to research can be so. Reinforced concrete resistance can use resistance function R (clamps its x1 x2,., xn,) said. One said the parameters of the computational structures, such as materials, geometric s

25、hapes, calculation method, etc. In addition, considering the fatigue work, calculating model and initial parameters and the resistance model can be related to time use type says: Type: R (t) is random R0 R0 is initially resisted process, resistance and is random process, the fatigue damage, is calcu

26、lation model of Kp mohan, not determining parameter, xi said stochastic process of material parameters. Many experiments on steel corrosion of steel erosion processes and formal consistent random process. Separation procedures, random time related resistance R (R0, t) can simply expressed as: Type:

27、R (t) is determined by the time R0 is arbitrary, and the function of early resistance.In addition, other cannot determine situation should be considered, such as not determine the resistance of actual materials, geometry size, and the size of calculation model. For a simple structure, arbitrary proc

28、ess resistance function, can be simple languages: Type: is the function with time related calculation model, calculating model is not determining parameter, and is determined by the calculation model structural resistance.For a single structure component with equation (7) says, can writing: Type:,an

29、d respectively expressed as changing with time, the calculated parameters of reinforced concrete structures geometry and material characteristics. is material resistance standard values.Mean and standard deviation equation (8) are as follows type says: In the concrete construction applications, the

30、concrete structure resistance stochastic process according to the following formula descending function: The is the concrete structure of the stochastic process, resistance,is related to the random variables, and are changing with time function. Based on the durability of concrete structure design l

31、evel, equation (11) can use the following formula: Type:when reinforced concrete reached the limit of concrete resistance when average;when reinforced concrete reinforced resistance when reaching limits average;the concrete reinforced concrete; the standard deviation coefficientin reinforced concret

32、e the standard deviation coefficient; ， separately for concrete and steel resistance decrease coefficient,; ，involves structure material, can gain; from material experiment.4 the engineering application Test axial compression reinforced concrete structural components, and get some structural resista

33、nce of the statistics.Consider the initial value: The concrete C30 averageStandard deviation20MnSi steel, average Deviation standard deviationThe initial stages of the size is. The resistance of concrete and steel respectively from reducing coefficient can Ref. 4, obtained. Under this condition, the

34、 axial compression reinforced concrete structure related random time resistance can gain.According to the design theory of reinforced concrete structure, resistance function,Type respectively andin early concrete and steel resistance. Second in the thesis uses the theory suggested to calculate rando

35、m time and decide resistance.Some statistics see table 1. From calculations can clearly see the, reinforced concrete resistance significantly increases over time, decrease. This phenomenon is important, and check the safety of the reinforced concrete is not be overlooked.Table 1 axial compression of

36、 the reinforced concrete structures changing with time resistanceTime/yearAverage/kNStandarddeviation/kNVariation coefficient5 conclusionFor civil engineering research, design, construction, characteristics of reinforced concrete structure is very important. Any changes with time of reinforced concr

37、ete materials research and testing, for structure of reinforced concrete structure maintenance, safety assessment is required. In order to structural reliability design, any changes with times actual resistance should be determined. In the thesis the characterized by materials for reinforced concrete research, which influence factors of concrete with concrete carbonation, corrosion of reinforcement. According to change from time to time of reinforced conc