Experimental Study On Anchorage Mechanism Of Locking Anchor Under Tension Together Shear Loads

The anchorage mechanism of the locking anchor under tension together shear loads is studied in the paper. Twenty-four specimens which differ in two kind of diameters (F 16,F20) and four kinds of load angles (00,30?45?600), are selected in the experiment. The load-deforming curve is got through the experiment of the each single anchor under tension together shear loads, then the axial and transverse deformations and ultimate bearing capacity of the anchor can be got too. The deforming rule of the anchor under the tension and shear loads is found by analysis of the load-deforming curve. Three sorts of functions (straight-line function, trilinear function and elliptical function) are used to illustrate and compare the ultimate bearing capacity of anchor; analyzing the demolish mode of the concrete and the locking anchor. Moreover, numerical simulate on this experimentation with finite element method is conducted. The experiment and numerical results are compared with each other in succession. In the end, the ultimate bearing capacity of the locking anchor is forecasted with artificial neural network (ANN) method and the forecasting value is compared with the experiment value. The following achievements are obtained:(1) The load- deformation curve of the locking anchor under tension together shear loads shows that the deformation of the anchor can be mainly divided into two stages: in the first stage it satisfies the linear law; in the latter, there is a big deformation per load pace, and behaves as nonlinear characteristic in evidence. No matter it is axial deformation or transverse one, it behaves the most nonlinear when the load angle is 45 degrees. The ultimate bearing capacity of two kinds of anchor increase with the enhancement of the load angle, and the anchor with diameter 20 millimeters increase more obviously than the other one. The elliptical function with the parameter a equals 2 can fit the ultimate bearing capacity in the experiment very well, which can provide a theory basis for the design of the anchor.(2) Under the tension together shear loads the invalidation of the anchor consists of two parts: one is declined cone failure of the concrete, the other is the failure of the anchor;When the load angle is 30 degrees, the form of the failure is almost the cone one, whichinduces the biggest depth of the cone peak and smallest area of the cone bottom. With the increase of the load angle, the cone peak become lower in depth and the cone bottom becomes smaller in area. After the failure of the anchor, the fracture surfaces have the following results: it is a rim of a cup when the load angle is 30 degrees, nearly a plane in the drew part and near 30 degrees inclined plane in the compression area when the load angle is 45 degrees and near 45 degrees inclined plane in the fracture when the load angle is 60 degrees.(3) The ultimate bearing capacity of anchor under tension together shear loads is analyzed using the finite element method in the paper. The result shows that the numerical results are comparable with the experimentation ones. The stress in concrete compressive zone shows that the fracture surfaces of concrete performs sector-arc distribution which is consistent with the experiment results.(4) The ultimate bearing capacity of anchor under tension together shear loads is forecasted by neural network method in the modem information technique. According to the compare between the forecasting value and the experiment one, we are convinced that this method holds a high accuracy. The influence factors of the ultimate bearing capacity of anchor are studied using the trained neural network together with the special output.