Stress/Strain

What is the study of Stress and Strain?

Is the study of how forces change an object’s shape.

What are all the points in order called in the stress and strain curve?

1. Limit of proportionality

2. Elastic limit

3. Yield point

4. Fracture point

What are all the points in a stress and strain curve in a Brittle material?

1. Limit of Proportionality

2. Elastic limit

3. Fracture point

Define tensile force?

They are forces that stretch an object.

Define compressive forces?

They are forces that squash an object.

What is the Equation for Stress?

Stress=force along the axis of the object/cross-sectional area of the object

If the force is tensile what happens to the stress?

The stress would be positive.

If the force is compressive what happens to the stress?

The stress would be Negative.

What are the Units of stress?

Pascals-(Pa) or (N/m2)-Newtons per metre squared

What is the Equation for Strain?

Strain=extension/original length

What is the Strain if the force is tensile?

Strain is Positive

What is the Strain if the force is compressive?

Strain is Negative.

Define the Breaking stress?

The stress needed to break a material.

Define the Ultimate tensile stress?

Is the maximum stress an object can endure.

What does it mean if a material is Ductile?

When a material can be stretched and shaped into a wire and stay that way.

What does it mean if a material is Brittle?

Brittle materials break and fracture before they experience a large extension.

What is special about the Fracture and Yield point of a brittle material?

They are both the same.