Final Answer:
The minimum edge-distance ratio of bolted joints in the primary structure is typically specified by engineering standards and codes, with common values ranging between **1.7 to 2.5 times the bolt diameter.**
Step-by-step explanation:
The edge-distance ratio in bolted joints refers to the distance from the center of a bolt to the nearest edge of the connected material, divided by the bolt diameter. It is a critical parameter in structural engineering, ensuring the structural integrity and safety of bolted connections. The specified minimum edge-distance ratio is based on structural standards such as those provided by organizations like the American Institute of Steel Construction (AISC) or the European Committee for Standardization (EN).
For instance, if the minimum edge-distance ratio is specified as 2 times the bolt diameter (d), the formula for calculating the minimum edge distance (e) would be e = 2d. This ensures that the bolted connection has sufficient material around it to resist the applied loads without compromising the structural stability. Deviating from these prescribed ratios may lead to reduced load-carrying capacity, increased vulnerability to failure, or compromised structural safety.
In summary, the minimum edge-distance ratio in bolted joints for the primary structure is a critical factor determined by engineering standards. Adhering to these specified ratios is essential to maintain the structural integrity of the connection and ensure that it can safely withstand the applied loads. Engineers and designers carefully calculate and adhere to these ratios to guarantee the reliability and safety of bolted joints in primary structures.