Parallel Finite Element Analysis For Functionally Graded Materials Notch

The continuous transition between different materials is realized by the functionally graded material,whose mechanical properties are greatly strengthened by the elimination of the macro interface.The engineering structures made by the functionally graded material often contain the V-notch,which will make the stress to be seriously concentrated or even infinite.The stress concentration will reduce the safety performance of the engineering components.Due to the time consumption is very large when the serial finite element method is used to analyze the functionally graded material structure,the parallel finite element program is made in this thesis.The stainless steel/ceramic gradient material is chosen as a research object.The transition mode of the composition of the functionally graded materials is defined.The stress singularity of the V-notch in the functionally graded material is studied.Firstly,the appropriate parallel technology is selected based on the scale of the studied stainless steel/ceramic functionally graded material and the existed computing environment.The finite element program is made by the Microsoft Visual Studio which supports OpenMP to integrate Intel Visual Fortran.The parallel computing process of the finite element method is mainly focused on the part of solving the global equilibrium equation with large amount of computation.The parallel Gauss elimination method is used to optimize the program,which greatly shorten the running time of the program.According to the characteristics of sparse matrix generated by finite element program,the PARDISO function of Microsoft Visual Studio compiler is used to optimize.The running time of the whole finite element program is further shortened.The influencing factors of parallel computing are also studied.The acceleration effect of parallel computing are tested basing on two aspects,which are different computing environments and the amount of data per thread.A good parallel acceleration state is found.The parallel finite element program is used to simulate symmetrical and inclined V-notch model in homogeneous materials and stainless steel/ceramic functionally gradient materials.The notch depths of 2cm,4cm,8cm,12cm,16cm and 20cm as well as the opening angle of 30 and 60 degrees are respectively considered.The finite element parallel program is applied to simulate the stress fields at the notch tip of various models.The stress intensity factor and the stress singularity order for each model are evaluated basing the finite element results.