The shape change of an object caused by an external force is called "deformation". Due to external causes or internal defects, the relative position of material particles changes, which can also cause morphological changes.
- Chinese name
- deformation
- Category
- Elastic deformation
- Nature
- Mechanical terminology
- Definition
- The object extends, shortens, bends, etc
Physical terms
Definition: we take the elongation 、 shorten 、 bend The equal change is called deformation. Deformation has Elastic deformation and Plastic deformation （ Plastic deformation ）Two. all object Caused by external force shape Change is called "deformation". Elastic limit : It means that the object is subject to external force Acting internally to resist external forces Interaction force Not more than one Limit value When, if External force action If it stops, its deformation can disappear completely and return to the original state, this limit value is called "elastic limit". The types of deformation are:
one Longitudinal deformation ： rod Both ends of pull When, length happen change ； two Volume deformation : Object volume Change in size; three shear : Two opposite objects surface Subjected to（ Tangential direction ） Couple When acting, the two surfaces are opposite displacement , called shear; four reverse : A cylindrical object with opposite directions at both ends moment It is twisted by action, called torsional deformation ； five bend : Fixed at both ends a steel bar , because load And bending, called flexural strain 。 Also includes Elastic material Of strain ， Plastic material Of Permanent deformation and liquid Of flow 。 No matter what deformation occurs, it can be summarized as Long change And shear. 6. Minor deformation refers to the deformation that cannot be seen by the naked eye. If a force does not change the object motion state , and there is no deformation above, it must be object Minor deformation has occurred. belong to Elastic deformation 。 
