Pyskunov S. Modelling of thermoviscoelastic deformation process, continual and discrete fracture of spatial prismatic and circular bodies of complicated form.

The aim of work consists of creation on the basis of semianalytical finite element method (SFEM) of the effective numeral going to the decision of continual fracture problem under protracted thermal and forces loading, linear and nonlinear fracture mechanics problems and problems of evolutional processes of fracture of difficult form spatial heterogeneous circular and prismatic bodies as a result of macroscopic defects and cracks propagation. A research object are processes of physically-linear and nonlinear deformation, damage accumulations and destruction as a result of of macroscopic defects and cracks propagation of spatial heterogeneous circular and prismatic bodies under the action of the protracted thermal and forces or cyclic loading. The article of research are values of stress-strained state parameters, damage parameter, fracture mechanic parameters, characteristic sizes and configuration of macroscopic defects and cracks in complicated form spatial bodies/ Solving correlations of semianalytical finite element method (SFEM) for heterogeneous circular and prismatic finite elements with variables of geometrical and physical parameters has been obtained. On the basis of displacements extrapolation the effective step-by-step algorithm of decision of SFEM nonlinear equations systems is worked out. The procedure of determination of thermoviscoelastic stress-strained state taking into account the damage accumulation is created. The new method of Cherepanov-Rice's J-integral calculation for discrete finite element model and algorithms of design of evolutional fracture processes at development of macroscopic defects under creep condition and cracks propagation in spatial bodies is worked out. Programmatic realization and approbation on test examples are executed. The efficiency of the offered FEM base and exactness of the obtained tasks problem solution of physically-nonlinear deformation and calculation of parameters of fracture mechanics has shown. The problem of research of influence on life-time value of presence of initial defects, temperature deformations and dependence of material mechanical properties from temperature for the responsible structure elements of power engineer - rotor of steam-gase turbine, tailpress and peer of shoulder-blade of the stationary gas-turbine setting and also practical problems about determination of fracture mechanics parameters and fracture propagation modeling in spatial objects.