Scientific paper ID 2010 : 2020/3

The strength of a weld depends on various factors, incl. and the presence of imperfections in it (admissible or inadmissible).

The aim of the paper is to study the stress in a point concentrator in a weld under the influence of an alternating stress field from a linear concentrator.

The aim is achieved by a virtual experiment with butt and T welds with a linear concentrator, in the area of influence of which a point concentrator of the pore type is formed and changes the local stress. To solve the problem, a hypothesis is used to multiply the effect of concentrators on the stress state in the welding. A spherical pore is used as a point concentrator. To assess the influence of the shape, data are also shown for a pore with a ridge (a hexagonal prism was used).

The hypothesis was validated by numerical experiment and comparison of the results obtained by direct measurement and by multiplying the influence of the concentrators. A good convergence between them has been noticed.

The maximum equivalent stress for a particular welded joint construction is determined by the product of the nominal stress, the value of the point concentrator and depends on its distance from the linear concentrator. The sharp edges in the point concentrator formed by the intersection of the walls is a reason for some deviations due to inhomogeneity of the stress around it.