|
|
|
|
|
Shrinkage Compensating Device
Indicates that the hold-down a mechanical device to adjust for wood movement, so that the wood shrinkage calculation and wood crush component are not included in the hold-down displacement. When checked, displacement is from fastener slippage and hold-down elongation only.
Always use Elongation at Maximum Capacity
Checking this box will cause the program to use the displacement or elongation at maximum capacity as the vertical hold-down displacement regardless of the force at the hold-down location. Otherwise, the program will factor the displacement by the proportion of actual to maximum force at the hold-down.
Using the maximum hold-down force is sometimes recommended because of the non-linear aspect of the slippage.
Checking the box is conservative with respect to shear wall deflection and the story drift check, however for low uplift force it may create more deflection than actually exists, and correspondingly lower rigidities for load distribution to that shear line, which is non-conservative with respect to shear wall design.