Stress state and strength of welded joints with V-shaped elements

It has been established that in the vicinity of V-shaped elements with a sharp apex, the stress field has a singularity of type <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>σ</mml:mi><mml:mo>→</mml:mo><mml:mi>∞</mml:mi></mml:math>, which requires the use of the concept of “stress intensity factor” in strength calculations. This need arose due to different dimensions of the SIF and fracture toughness. Special criteria for the destruction of structures with V-shaped stress concentrators have been developed, which include, as special cases, the criteria of classical mechanics and the criteria of fracture mechanics. An experimental test of the proposed criteria and calculation methods was carried out. The information obtained is useful for analyzing welded joints on main pipelines and other equipment.