Technique of Engineering Structures Strength Analysis Taking into Account Damageability of Materials during Creep

This work describes research methods of complex problem solution to estimate strength and durability of flat laminas and multiple layer shells of rotation with an account of plastic deformations, temperature creep, the hydrogen corrosion and degradation of material's properties in time. The practical solutions of the problems of calculating the stress-strain state of a flat lamina with a hole was made. The lamina was under pressure at a temperature of 500 degrees C. The dependence of the time of the onset of the limiting state on the value of the damage parameter for three different pressure values is investigated. The components of the stress-strain state and the time to failure of the laminas were determined. As the limiting state, the moments of the onset of the process of destruction and complete destruction of the laminas were considered. In the course of the research it was found that the choice of the damage parameter limiting value has a significant effect on the fracture time evaluation, and this effect is especially pronounced when performing calculations taking into account the motion of the fracture front. If the damage parameter is incorrectly selected, the time to failure estimate can be either overestimated or underestimated. On the basis of the obtained results of calculations, recommendations are formulated for the choice of the adequate damage parameter values.