Studies of Kernel Function in the Nonlocal Friction Model and Its Application on Bolt

To investigate the characteristics together with optimum selection of kernel functions in the nonlocal friction model,the nonlocal friction model proposed by Oden et al is modified.The kernel function in model is replaced by exponential function,trigonometric function,negative exponential function and power function.Based on the elastic solution of shear stress on bolt surface of the wholly grouted anchor derived with Mindlin's solution of displacement,wholly grouted anchor is analyzed by the modified nonlocal friction models which have four different kernel functions.The shear stress distributions on bolt surface given by the modified nonlocal friction models and the local friction models are similar.The nonlocal friction effect is also discussed.The results obtained by the modified nonlocal friction model with different kernel functions and local friction model are compared with experimental results.It is found that the calculating results obtained by modified nonlocal friction model with the negative exponential kernel functions agree better with experimental results.