不同疲劳加载频率下植筋混凝土梁疲劳性能的试验研究

发布时间：2018-01-17 18:07

本文关键词：不同疲劳加载频率下植筋混凝土梁疲劳性能的试验研究　出处：《河北工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：本文主要对3根试验梁进行分析(共设计7根),植筋深度均为20d=500mm,试验材料均相同。首先对一根植筋梁进行静力试验,得出试验梁跨中段在同时承受弯矩和剪力情况下的极限承载力,并将其与规范规定的计算公式相互对比,验算整浇梁公式是否适用于植筋梁。然后根据静载试验的极限承载力对两根同样的植筋梁进行疲劳试验,分析不同阶段时的各材料性能变化规律,对比其经过不同频率的疲劳循环荷载后的极限承载力、挠度和刚度的变化规律。本文的研究结论如下:1、通过静载试验的极限承载力和整浇通筋梁的设计值对比。植筋深度为20d时,植筋梁受弯承载力满足要求。2、疲劳加载试验对植筋梁的极限承载力影响不大,但使其破坏机制由跨中正截面受弯破坏变为植筋端头处斜截面弯剪破坏,因此,在进行受弯植筋梁承载力计算时,除考虑植筋抗拔承载情况外,尚应对植筋端头处混凝土弯剪破坏引起足够重视。3、疲劳加载对植筋梁造成的疲劳累积损伤集中在前50万次的疲劳加载过程。4、在一定频率范围内,低频加载对植筋梁造成的累积损伤要大于频率稍高时疲劳加载对植筋梁造成的疲劳累积损伤。
[Abstract]:In this paper, three test beams are analyzed (7 of them are designed, the depth of planting tendons is 20 days or 500mm, and the test materials are the same. First, a static test of one beam is carried out. The ultimate bearing capacity of the mid-span of the test beam under the condition of both bending moment and shear force is obtained, and the calculation formula is compared with the formula specified in the code. Check whether the formula of cast-in-place beam is suitable for planting steel beam. Then according to the ultimate bearing capacity of static load test carry on the fatigue test to two same beam-planting beam and analyze the change law of material performance at different stages. The variation of ultimate bearing capacity, deflection and stiffness after fatigue cyclic loading with different frequencies is compared. The conclusions of this paper are as follows: 1. The ultimate bearing capacity of static load test is compared with the design value of cast-in-place beam. When the depth of planting steel bar is 20 days, the flexural capacity of the beam meets the requirement of .2. Fatigue loading test has little effect on ultimate bearing capacity of reinforced beam, but the failure mechanism is changed from flexural failure of normal section of span to bending shear failure of oblique section at the end of reinforcement. In the calculation of flexural beam bearing capacity, in addition to taking into account the pull-out load, it is necessary to pay enough attention to the flexural shear failure of concrete at the end of the planting bar. The fatigue cumulative damage caused by fatigue loading is concentrated in the first 500,000 times of fatigue loading process. 4, in a certain frequency range. The cumulative damage caused by low frequency loading is greater than that by fatigue loading at higher frequency.
【学位授予单位】：河北工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU377.9

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