基于声发射的高强混凝土轴拉与劈拉损伤演化特征OA北大核心CSTPCD

The whole stress-strain curve tests of axial tension and split tension were carried out on high strength concrete with a compressive strength of about 100 MPa.The acoustic emission characteristics of the two tests during the whole process were compared and analyzed,and the failure mechanism and damage evolution of high strength concrete were revealed.The results show that the axial tensile specimen is prone to eccentric tension due to the unstable expansion of macro-cracks after the peak stress,while the split tensile specimen has a more uniform strain distribution and stable crack propagation.The cumulative acoustic emission hits curve of the axial tension specimen is convex downward at the peak stress,while the curve of the split tension specimen affected by the local concentrated stress is convex upward.The failure of axial tensile specimen is dominated by tensile stress,and the failure of split tension specimen undergoes the transformation from tensile-shear mixed mode to tensile mode.