Structural connections are points in a structure where components are joined together. Each connection presents an area of potential weakness in the structure that must be addressed by selecting an appropriate connection for the task. When structures are designed, architects and engineers evaluate the loads that will be encountered in various areas to determine which structural connections should be used for maximum stability, strength, and safety. Building codes usually provide minimum standards to ensure that structures are reasonably safe.
The connection is more than a point where two pieces of a structure are connected. Structural connections also provide an opportunity to transfer loads from different areas of the structure and are used to add strength and support to the finished structure. Each structural connection contributes to the overall strength of the finished product and can make the difference between catastrophic failure and the ability to successfully resist both internal and external stresses.
Some structural connections are welded, while others are made with fasteners. Rivets, brackets, and pins can all be used. Things that dictate the strength of a finished connection include the materials used, the size of the components, and how well the connection is fitted and installed. If workers fail to install the components properly, the connection will be prone to failure even if the correct materials for the job were chosen. For example, failing to complete a weld can create a weak point that will be vulnerable to stresses.
Loads on a structural connection include the weight of the structure itself as well as pressures such as high winds, live weights like cars and people moving across the structure, and earthquakes. When developing structural connections, engineers must think of the types of loads that will be encountered and their characteristics. Designs take worst case scenarios into account and redundancies within the structure are used to ensure that it will remain standing, even in very adverse conditions such as hurricanes.
Structural connection design can utilize generic components that are readily available or custom fittings developed with a specific structure in mind. During construction, these key points will be carefully inspected to confirm that they were installed correctly, using the right materials and techniques. Inspectors can also request materials testing and other measures to confirm that the structural connections will be safe. Identifying errors early helps people avoid costly retrofits and other expensive measures that might be needed to correct structural problems.
