Ultimate stress

Definition

Ultimate stress is the maximum stress that a material can withstand before failing or fracturing. It is a critical value in understanding the strength and durability of materials under load.

5 Must Know Facts For Your Next Test

1. Ultimate stress is typically measured in units of Pascals (Pa) or MegaPascals (MPa).
2. It represents the peak point on a stress-strain curve for a material.
3. Beyond ultimate stress, materials undergo plastic deformation until they reach the breaking point.
4. The ultimate stress value varies significantly across different materials such as metals, polymers, and composites.
5. Engineering designs often use ultimate stress values to ensure safety and reliability under extreme conditions.

Review Questions

• What units are commonly used to measure ultimate stress?
• How does ultimate stress relate to the stress-strain curve?
• Why is it important to consider ultimate stress in engineering design?

Related terms

Yield Stress: The amount of stress at which a material begins to deform plastically.

Stress-Strain Curve: A graph that represents the relationship between the applied stress and the resulting strain in a material.

Plastic Deformation: Permanent deformation of a material after the yield point has been surpassed.