It is measured in units of force per unit area of cross-section (N.m-2) denoted byÏƒ(“sigma”). Strain is the deformation that takes place in the body.It is the ratio of the increase in length, DLto the original length (L), Represented by symbolÎµ(“epsilon”) or e. And according to hook’s law: Ïƒ = E e Or, E = Ïƒ/e Putting values of stress and strain in above equation we get:- E = FÃ-L/AÃ-DL Young’s modulus of elasticity (E) is defined as the ratio of unit stress to unit strain .For elastomers such as rubber the elastic limit is much larger than the proportionality limit.
It is measured in units of force per unit area of cross-section (N.m-2) denoted byÏƒ(“sigma”). Strain is the deformation that takes place in the body.Tags: Transition Words Illustration EssayHomework Oh Homework By Jack PrelutskyRestaurant Business Plan Template WordUcf Freshman Application EssaySteps In Business Planning ProcessNicmar AssignmentsFaerie Queen Essay
and when we apply a force F to the spring It stretches And it extends length,x, that is, the strain, caused by the stress is F = mg.
Also, In terms of mechanics hooks state that:- “For an elastic material stress applied on a body is directly proportional to the strain produced” That is, Ïƒ Î± e Or Ïƒ = E e Where, Ïƒ is the stress applied e is the strain developed E is the YOUNGS MODULUS OF ELASTICITY Now STRESS it is the force causing the deformation.
Prior to the yield point the material will deform elastically and will return to its original shape when the applied stress is removed.
Once the yield point is passed some fraction of the deformation will be permanent and non-reversible. This definition is rarely used, since dislocations move at very low stresses, and detecting such movement is very difficult.
The lowest stress at which permanent deformation can be measured.
This requires a manual load-unload procedure, and the accuracy is critically dependent on equipment and operator skill.
Thestress-straincurve is a graphical representation of the relationship betweenstress, derived from measuring the load applied on the sample, andstrain, derived from measuring thedeformationof the sample, i.e. The nature of the curve varies from material to material.
The elastic limit is where the graph departs from a straight line.
The generalized Hooke’s Law can be used to predict the deformations caused in a given material by an arbitrary combination of stresses.
The linear relationship between stress and strain applies for The generalized Hooke’s Law also reveals that strain can exist without stress.