Книга: Deformation (Engineering): Materials science, Force, Tensile strength, Compressive strength, Simple shear, Bending, Structural failure, Deformation (mechanics), ... (geometry), Plastic deformation in solids

In materials science, deformation is a change in the shape or size of an object due to an applied force. This can be a result of tensile (pulling) forces, compressive (pushing) forces, shear, bending or torsion (twisting). Deformation is often described as strain. As deformation occurs, internal inter-molecular forces arise which oppose the applied force. If the applied force is not too large these forces may be sufficient to completely resist the applied force, allowing the object to assume a new equilibrium state and to return to its original state when the load is removed. A larger applied force may lead to a permanent deformation of the object or even to its structural failure. In the figure it can be seen that the compressive loading (indicated by the arrow) has caused deformation in the cylinder so that the original shape (dashed lines) has changed (deformed) into one with bulging sides.