[en] Solutions useful for the determination of the state of stress and stability in panels, plates and shells possessing both reinforced and unreinforced holes are presented. Also discussed are problems involving the local reinforcement of mating structural elements. Depending on the problem either plane stress elasticity or plate and shell theory is employed for the structural member. The reinforcement is treated as a beam having tensile, torsional and flexural stiffnesses. A restriction on the reinforcement is that the width of the beam is small compared to the radius of the hole, plate or shell. In the case of a panel, it is furthermore assumed that the hole is small compared to the depth of the panel and that the distance of the hole's center to an edge is large compared to the radius of the hole. (Auth.)