If a material subjected to a compressive load changes shape but returns to its original shape after the load is removed, does this indicate that the ultimate tensile strength was not reached?

When a material is subjected to a compressive load and experiences a change in shape that is reversible, this phenomenon is indicative of elastic deformation. Elastic deformation occurs when the material is able to return to its original shape once the load is removed. This response implies that the applied stress did not exceed the material's elastic limit.

The ultimate tensile strength of a material represents the maximum stress that it can withstand while being stretched or pulled before failing or breaking. Since the scenario described pertains to compressive loads and highlights a scenario of elastic recovery, it suggests that the load applied did not reach the point where the material would fail or undergo permanent deformation.

In summary, the observation that the material returns to its original shape after the load removal reinforces the notion that the ultimate tensile strength was indeed not reached, as no permanent deformation occurred.