Why do we use engineering stress and strain?

The engineering stress-strain curve is ideal for performance applications. The true stress-strain curve is ideal for material property analysis. Thus, any calculations involving force or displacement–such as toughness or ultimate tensile strength–can be done directly from an engineering stress-strain curve.

Why is it important to work with stress and strain instead of force and displacement?

Force and displacement data will vary if the specimen dimension changes even if it is from the same material. That is why we normalize force with its cross section and displacement with its gauge length to arrive at stress and strain which becomes now more generic.

How does the engineering stress-strain diagram differ from the true stress-strain diagram?

The curve based on the original cross-section and gauge length is called the engineering stress-strain curve, while the curve based on the instantaneous cross-section area and length is called the true stress-strain curve.

What is meant by stress and strain?

In simple terms we can define stress as the force of resistance per unit per unit area, offered by a body against deformation. Strain is the ratio of change in length to the original length, when a given body is subjected to some external force (Strain= change in length÷the original length).

Why is engineering stress different to true stress?

True stress is the applied load divided by the actual cross-sectional area (the changing area with time) of material. Engineering stress is the applied load divided by the original cross-sectional area of material. The cross-section does not remain constantly and will be different from the given value of diameter.

What is stress structure?

When a structural member is loaded, deformation of the member takes place and resistance is set up against deformation. This resistance to deformation is known as stress. The stress is defined as force per unit cross sectional area.