【摘要】：為研究三點彎曲混凝土梁撓度δ與裂縫口張開位移CMOD的關(guān)系,對五組尺寸相同、強度不同的預制切口梁進行三點彎曲試驗,獲得加載全過程的P-δ曲線和P-CMOD曲線。由于試驗中的P-δ曲線和P-CMOD曲線同步測得,取相同P值下對應的δ值與CMOD值,即可得到一一對應的δ值與CMOD關(guān)系。分析表明:δ-CMOD關(guān)系可分為非線性和線性兩部分,采用數(shù)值分析確定兩部分的擬合參數(shù);針對混凝土強度的影響,提出各參數(shù)關(guān)于強度的經(jīng)驗公式。最后,通過對不同批次、相同成分的混凝土斷裂能對比分析,證實了本文擬合關(guān)系的可靠性。采用本文公式由CMOD計算的斷裂能G_F~(P-δ(CMOD))的標準偏差為5.93N/m,遠小于由撓度實測值計算的斷裂能G_F~(P-δ)的標準偏差21.05N/m,且G_F~(P-δ(CMOD))的平均值更接近已知的混凝土的斷裂能。
[Abstract]:In order to study the relationship between deflection 未 and crack opening displacement (CMOD) of three-point bending concrete beam, five groups of prefabricated notched beams with the same size and different strength were subjected to three-point bending tests. The P- 未 curves and P-CMOD curves of the whole loading process were obtained. Because the P- 未 curve and P-CMOD curve are measured synchronously, the relation between 未 value and CMOD can be obtained by taking the corresponding 未 value and CMOD value under the same P value. The analysis shows that the 未 -CMOD relation can be divided into two parts: nonlinear and linear, the fitting parameters of the two parts are determined by numerical analysis, and the empirical formula of each parameter about strength is put forward in view of the influence of concrete strength. Finally, the reliability of the fitting relationship is confirmed by comparing and analyzing the fracture energy of concrete with different batches and the same composition. The standard deviation of GSP ~ (P- 未) (CMOD) calculated by CMOD formula is 5.93 N / m, which is much smaller than that of GSP ~ (P- 未) calculated by deflection measurement, and the average value of GSP ~ (P- 未) (CMOD) is closer to the fracture energy of known concrete.
【作者單位】： 貴州大學空間結(jié)構(gòu)研究中心;
【基金】：國家自然科學基金(51408144;51568012) 貴州省科學技術(shù)基金項目([2016]1040) 貴州省留學人員科技創(chuàng)新項目(Z164096) 貴州大學引進人才科研基金([2013]01)
【分類號】：TU528

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1 王秋雨;基于進化算法的三點彎曲梁混凝土軟化本構(gòu)關(guān)系研究[D];浙江工業(yè)大學;2012年

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