1. Analysis of initial stresses and deformations caused by virtual distortions.- 1.1. Distortions in elastic body.- 1.2. Analysis of stresses and deformations caused by distortions.- 1.3. Examples of structures with distortions.- 1.4. Distortions in biphase body.- 1.5. Surface distortions.- 2. Simulation by virtual distortions.- 2.1. Simulation of geometrical and physical modifications in structures.- 2.2. Simulation of shape modifications in continuous bodies.- 3. Optimal control by means of imposed virtual distortions.- 3.1. Passive control of stresses (prestress).- 3.2. Quasi-statical active control problems.- 3.3. Active damping of vibration.- 3.4. Active strategy of avoiding resonance.- References.