|
|
|
|
|
Shearwalls allows you to designate a wall as Non-wood/Proprietary to allow for the placement of proprietary shear-resisting elements, such as Simpson Strong-Walls®, or to include a length of a shear line that is made of some other material, like steel, concrete or masonry.
Proprietary elements are typically placed where shear resistance is required but the space is too short to allow for wood shear walls with allowable height-to-width ratios.
Non-wood/Proprietary walls cannot have openings. They are meant to model short proprietary shear segments or walls made of materials for which we do design and are not concerned with the internal structure.
No materials are input for non-wood or proprietary walls; instead you input a capacity and a stiffness or deflection at maximum capacity for these walls, independently for seismic and wind design.
Designed vs. Not-to-be Designed
The program allows you to specify that these walls are "not to be designed" in the sense of comparing their capacity to the applied load. In this case no capacity is input, but the walls still have a stiffness and their deflection will be calculated.
If the walls are to be designed, we are assuming that the wall is a proprietary element and you input the capacity and deflection at capacity for the entire element. These values come from data published by manufacturers like Simpson and Mitek for specific shear resisting elements of a predefined length.
If the walls are not to be designed, instead of deflection you input the wall's unit rigidity in lb/in/ft or N/mm/m ,which represents the stiffness of a non-wood wall such as a concrete, masonry or moment-frame wall. There is no capacity input.
Force Distribution Method
The program does not allow Non-wood/Proprietary walls to use capacity-based force distribution, even if the walls are to be designed and capacity is input. The reason for this restriction is that we are not confident that the assumptions that underly force distribution based on capacity are valid for mixed material types.
Hold-downs and Compression Forces
Hold-down and compression-end forces will be calculated at proprietary and non-wood elements, but no hold-down device is assigned to the hold-down and no hold-down capacity check or design for compression forces is performed.