Civil Engineering Professional Engineer Practice Exam

Which of the following is NOT classified as a structural force?

1. Compression

2. Shear force

3. Plastic deformation

4. Tension

The correct answer is: Plastic deformation

In the context of structural engineering, structural forces are specific types of forces that act on a structure and influence its stability and integrity. Compression, shear force, and tension are all types of structural forces that directly affect how structural elements behave under loads. Compression refers to the force that pushes materials together, inducing a shortening effect. Shear force entails sliding forces that cause different parts of a body to move in different directions, while tension involves pulling forces that elongate materials. These forces are fundamental in analyzing and designing structures to ensure they can withstand various loads. On the other hand, plastic deformation describes a material’s permanent change in shape when it exceeds its elastic limit due to applied stresses. While plastic deformation is a relevant concept in material science and affects how materials behave under stress, it is not classified as a structural force itself. Instead, it results from the application of structural forces and is a response of the material to those forces. Understanding the distinction between structural forces and material responses like plastic deformation is crucial for effective structural analysis and design.