Stress

Within structural engineering, stress refers to the internal forces that develop within materials as they are subjected to loads. It is a fundamental concept that determines how much load a component can support. Structural engineers evaluate, at least by inspection, every component within a structure to ensure that it can withstand the expected forces without failure.

There are several types of stress that engineers consider. These including tensile, compressive, and shear stress. Tensile stress occurs when a material is pulled apart, while compressive stress results from forces pushing material together. Shear stress, on the other hand, arises when forces act parallel to a surface, causing layers within a material to slide against one another. Each type of stress affects materials differently, and understanding their effects is essential for selecting appropriate construction materials and assembly.

Stress analysis plays a crucial role in determining whether a structure can handle expected loads, such as the weight of the structure itself, occupants, environmental forces like wind or earthquakes. For instance, a certain species and grade of sawn lumber may be rated to withstand 1000 psi bending stress. Another wood member, such as a laminated veneer lumber (LVL) member, might be rated at 3000 psi. This means that the bending analysis of the component would dictate that a smaller LVL member could be used to support the same expected load.