再生混凝土梁损伤演化的分形研究

Fractal research on damage evolvement of recycled concrete beam

通过对4根集中荷载作用下再生混凝土简支梁的试验研究,分析了其在分级荷载作用下从开裂到破坏过程中裂缝演化、分布的特征,证明了再生混凝土梁表面裂缝分布具有分形性质,并且不同损伤状态下构件表面裂缝的分维数与其所受剪力具有良好的线性关系,与跨中挠度和损伤变量之间也存在良好的量化关系。研究表明,该分维数可作为再生混凝土构件损伤程度的一个衡量指标,从而为再生混凝土结构从开裂到破坏过程的非线性研究提供了新的思路和方法。

In this paper, experimental research on crack of four recycled aggregate concrete simple beams under concentrated load was presented. Through the analysis of evolution, distribution characteristics of crack from its crack to destruction in the classification of loads,it is verified that the surface cracks on the recycled aggregate concrete beams take on the fractal behavior and there is a very good linear relationship between the fractal dimension of the surface crack in the different damage state and its suffered shear. Between the fractal dimension of the surface crack and the mid-span deflection, damage variable also have a good quantitative relationship. Accordingly,the fractal dimension can be regarded as an index to evaluate damage degree of recycled aggregate concrete beam, which provides a novel ideas and methods for the nonlinear study from its crack to destruction.