【正文】 =簡支節(jié)的長度；M/EI=截面曲率；m =質量。整個曲率圖可由三對坐標組成:開裂時,開裂瞬間，開裂后。然而,由于負載標準只在ISIS M0301（里茲卡拉和穆夫提 2001）中明確規(guī)定,故目前尚不清楚每個規(guī)范的標準。 最小值性質最小值520 （MPa） （GPa） （MPa） ɑ/d 2640174 為了檢驗公式的準確性,在多次給定負荷條件下，分析由撓度試驗得出的撓度和由每個方程所計算的撓度作比較。
CSA S80602（CSA 2002）表明，在計算撓度時彎矩曲率法非常適合FRP構件，因為彎矩曲率圖分為兩個線性近似區(qū)域:第一個是在混凝土破壞前的區(qū)域,第二個是混凝土破壞之后的區(qū)域。例如,約斯特等（2003）認為,方程式（7）的準確性主要依賴于其構件的配筋率，并得出結論，方程式的形式不變,但應對α進行修改，由此得出α的方程式： （9）=平均配筋率ACI 440委員會（ACI 2004)對ACI
(ACI 2003)中的方程也進行了修改。=鋼筋的彈性模量。如果使用FRP加固構件，此時有效慣性矩可由方程（2）所得 (2) 研究人員做了進一步的研究,以便于確定一個類似于方程式（1）但更快捷的有效慣性矩方程。本文只討論瞬時撓度。統(tǒng)計數(shù)據(jù)。這些構件與芳綸玻璃鋼鋼筋、玻璃玻璃鋼或碳纖維塑料筋配筋率、幾何和材料屬性不同。 α=bond dependent coefficient
（until more data bee available, α=）。Statistics.Introduction Fiberreinforced polymer
FRP reinforcing bars are currently available as a substitute for steel reinforcement in concrete structures that may be vulnerable to attack by aggressive corrosive agents. In addition to superior durability, FRP reinforcing bars have a much higher strength than conventional mild steel. However, the modulus of elasticity of FRP is typically much lower than that of steel. This leads to a substantial decrease in the stiffness of FRP reinforced beams after cracking. Since deflections are inversely proportional to the flexural stiffness of the beam, even some FRP overreinforced beams are susceptible to unacceptable levels of deflection under service conditions. Hence, the design of FRP reinforced concrete
（FRPRC） is typically governed by serviceability requirements and a method is needed that can calculate the expected service load deflections of FRP reinforced members with a reasonable degree of accuracy. The objective of this paper is to point out the inconsistencies in existing deflection formulas. Only instantaneous deflections will be discussed in this paper.Effective Moment of Inertia Approach ACI 318
（ACI 1999）and CSA
(CSA 1998) remend the use of the effective moment of inertia, Ie, to calculate the deflection of cracked steel reinforced concrete members. The procedure entails the calculation of a uniform moment of inertia throughout the beam length, and use of deflection equations derived from linear elastic analysis. The effective moment of inertia, Ie, is based on semiempirical considerations, and despite some doubt about its applicability to conventional reinforced concrete members subjected to plex loading and boundary conditions, it has yielded satisfactory results in most practical applications over the years. In North American codes, deflection calculation of flexural members are mainly based on equations derived from linear elastic analysis, using the effective moment of inertia, Ie, given by Branson’s formula
(1965) （1）=cracking moment。Critical Review of Deflection Formulas for FRPRC MembersCarlos Mota1。 Serviceability。 and =modulus of elasticity of steel reinforcement. The ISIS Design Manual M0301
（Rizkalla and Mufti 2001） has suggested the use of an effective moment of inertia which is quite different in form pared to the previous equations. It suggests using the modified effective moment of inertia