Presenting the mathematical theory of period problems in plane elasticity by methods of complex variables. The most general formulations of such problems are proposed under the assumption that the stresses are periodic and the displacements are quasi-periodic. The general expression of complex displacements are illustrated. Periodic welding problem

1. Periodic Boundary Value Problems for Analytic Functions 2. Periodic Problems for Isotropic Material in Plane Elastic Problems 3. Periodic Problems for Anistropic Medium 4. Problems with Periodic Moving Loads on Isotropic Elastic Half-Plane 5. Periodic Crack Problems in Plane Elasticity 6. Doubly-Periodic Problems in Plane Elasticity