Saved Bookmarks
| 1. |
Explain theoretically stress strain curve |
| Answer» \tIt is a curve between stress and strain.\tA graph is plotted between the stress (which is equal in magnitude to the applied force per unit area) and the strain produced.\tThe graph helps us to understand how a given material deforms with increasing loads.\tThe curve between O and A, is a straight line. This means stress is directly ∝ to strain. In this region Hooke’s Law is applicable.\tIn this region the material behaves like an elastic body.\tIn the region from A to B, stress and strain are not directly ∝. But still the material returns to its original dimension after the force is removed. They exhibit elastic properties.\tThe point B in the curve is known as yield point (also known as elastic limit) which means till this point the material will be elastic in behaviour and the stress corresponding to point B is known as yield strength (Sy) of the material.\tThe region between O and B is called as Elastic region.\tFrom point B to point D we can see that strain increases rapidly even for small change in stress.\tEven if we remove the force the material does not come back to its original position. At this point stress is zero but strain is not zero as body has changed its shape.\tThe material has undergone plastic deformation.\tThe material is said to be permanent set.\tThe point D on the graph is known as ultimate tensile strength (Su) of the material.\tFrom D to E we can see that stress decreases even if strain increases.\tFinally at point E fracture occurs. This means the body breaks.\xa0 | |