Three-dimensional Model And Forward Modeling Of T-beam Prestressed Pipeline Disease

Prestressed T-beams are widely used in practical engineering due to their simple structure,cost saving and strong applicability.In the construction process,voiding diseases often occur due to construction techniques and the like.Therefore,this paper mainly studies the three-dimensional model and forward modeling of T-beam pipeline diseases,aiming at detecting and preventing the actual engineering T-beam pipeline diseases.In this paper,the meshless Galerkin method with mixed absorption boundary conditions is used as the basis of numerical simulation.The meshless method frees the steps of meshing,uses the sliding least squares method to obtain the shape function,and utilizes the better continuity of the shape function,so that the meshless method has high precision,simple form,suitable range,not limited to the net.The characteristics of the grid.The advantage of the SARMA boundary condition and the transmission absorption boundary of the mixed absorption boundary condition set can achieve better boundary absorption effect.The main research results are as follows:1.The model test results show the ground penetrating radar(GPR)to detect line of 2d and 3d map analysis precision of ground penetrating radar(GPR)to detect completely accord with the actual setting of model disease,can achieve inspection2.The basic principles of wave equation and meshless method are derived.The negative exponential weight function,quadratic basis function and Gaussian numerical integral are selected according to the principle of computational efficiency and computational precision,and the penalty function is used as the loading boundary condition.The principle of mixed boundary conditions and the loading mode in numerical simulation are expounded.The advantages and disadvantages of the improved boundary SARMA and transmission absorption boundary are theoretically explained.3.In MATLAB programming,taking the model test as the prototype,a forward modeling model based on the meshless Galerkin method and the mixed absorption boundary is established.The simulation images of each part are analyzed,and the simulation program based on the transmission absorption boundary is compared.It is concluded that the mixed absorption boundary conditions are better in the absorption of the boundary and the improvement of the overall effect.Based on the mesh-free method of hybrid absorbing boundary,the overlapping voids found in the simulation process are discussed in depth.The related factors of the missing width of the underlying cavity fault are analyzed,which provides a reference for the actual engineering interpretation image.4.The numerical simulation results of the meshless method are compared with the measured images of the 3D model.The waveform diagrams are basically the same,and the influence degree and difference of the steel bars and depths on the holes are matched.Fully validate the applicability of the numerical simulations used in this paper for T-beam disease simulation.