The technique of the research problem solution of influence of different types of concentrators on the stress-strain state of main gasline pipes involving compact flat specimen is considered. The algorithm of carrying out numerical experiment and its realization in the APDL language in the ANSYS is developed, one of possible forms of additional stress concentration – a circle is considered, and shown its influence on stress redistribution, the size and a form of area of a biaxial stress.

Keywords: stress-strain state, flat specimen, stress concentration, finite element method, automation of finite elements grid creation, defects in pipes, weld