North Carolina Building Contractor License Practice Exam

What is the minimum percentage of yield strength that must be developed by mechanical connections?

1. 85%

2. 90%

3. 100%

4. 125%

The correct answer is: 125%

Mechanical connections in construction are critical to ensuring that structural elements can effectively transfer loads without failure. The requirements for the percentage of yield strength that must be developed by these connections are established to guarantee the integrity and safety of the structure. Requiring a minimum of 125% yield strength means that mechanical connections must be able to sustain loads that exceed the yield strength of the material being used. This provides a safety margin that accounts for factors such as unexpected loads, variations in material properties, and potential degradation over time. By ensuring that connections can develop this higher percentage of yield strength, designers and builders enhance the resilience of structures, particularly in adverse conditions. In contrast, lower percentages such as 85% or 90% do not provide the same level of assurance and could lead to potential failure if the connection encounters unexpected stresses. A requirement of 100% yield strength, while seemingly adequate, does not account for any safety factor that may be necessary in real-world applications. Therefore, the requirement for connections to develop at least 125% of yield strength is a standard practice aimed at maintaining structural safety and performance.