Do the loadunload curves follow the same path Why or why not

Do the load/unload curves follow the same path? Why or why not

Solution

It actually depends on what kind of material loading and unloading is supposed to be performed such as plastic, elasto-plastic or elastic one . In case of plastic, a material doesnot recover when the external load is removed from it and due to this it makes loading and unloading curves to follow different paths. While in case of elastic material it recovers to its original shape when it is relieved from external load and this makes loading and unloading curves follow the same path. Whereas elasto-plastic materials have characteristics of both plastic as well as elastic.