Stress state of ship welded elements with round holes and concentric inserts
Marine vessels are specific structures that contain a relatively large number of pipelines, electrical cables and etc. They have a large length and, consequently, numerous intersections with sheet elements of ships hull.. Reinforced holes make changes in the stress-strain state of flat elements and are, as a rule, stress concentrators. Despite the accumulated experience, the availability of normative and technical documentation for the operation and repair of such structures, there are no algorithms and formulas suitable for engineering calculations that take into account individual features of structures. This article deals with the problem of applying methods of elasticity theory to evaluate stresses in ship hull structures. The physical model was a round plate with a concentric hole with a rigid insert. Formulas for calculating two normal and one tangent stress are given. The polar coordinate system was used. Examples of calculations for determining stresses are given. In particular, the dependences of radial and tangential stresses on the polar angle, radius, and outer radius of the plate are shown. It has been shown that when moving away from the hole, the stress state tends to uniform stretching. The hard-insert version significantly changes the local stress field.