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Load Generation

Important Note – These are descriptions to changes implemented in WoodWorks Shearwalls for version 9.3 and may not reflect current behavior.

  1. Crash due to Combination of Minimum Wind Loads and Note 8 Low-rise Loads (Bug 2642)

    Shearwalls would sometimes crash when the following conditions hold:

    This has been corrected.

  2. All-heights Coefficients for Walls Extending Between Blocks (Bug 2473)

    When a building is made from multiple intersecting blocks, the program creates two walls along one of the sides of an "L", but only one wall along the side of another. The two walls are assigned to different blocks for wind load creation, but one the one wall extending between two blocks and until now was assigned to only one block for wind load generation. When this occurs you have no way of splitting the long wall up and manually assigning different blocks to the separate walls. This also occurs when you manually joined walls from separate blocks.

    This could create incorrect wind loads for blocks with radically different height-to-width ratios, for example, that a wall extends from a one-storey block to high one with several stories. It has been corrected and the program internally splits the wall up and assigns the co-efficients from the correct blocks to the walls.

    Refer to an explanation in the Help files, under Canadian wind load procedures, for a picture and more details.

  3. Low Rise Wind Loads Due to Note 8 for Positive Cp Coefficients (Bug 2550)

    Low-rise wind loads due to Note 8 of ASCE 7 05 Figure 6-10 (now Fig. 28.4-1), that specifies zone 3 loads on a portion of a zone 2 windward roof, were being generated for high angles with positive Zone 2 co-efficient GCpf, when they should be limited to low angles with negative GCpf,. The resulting zone 3 loads have a negative coefficient that combined with the loads with a positive zone 2 coefficient to reduce the total load on the roof, creating non-conservative wind loading. This has been corrected

  4. Base Shear due to Manual Building Masses on North-South Lines (Bug 2518)

    When a building mass is manually added to a North-south shearline, the seismic load from the resulting mass did not contribute to base shear on the structure, creating lower-than-expected forces distributed to the building levels. However, the seismic load from the building mass is created, using the base shear computed without the contribution of that load. Furthermore, when any seismic load is entered manually, it is not included in the base shear to be distributed to the rest of the building. This is not incorrect, but has been made more evident to the user via a note beneath the seismic information table and in the log file.

    1. Load and Force Distribution and Engineering Design
  5. Directionality of Uplift Wind Loads (Bug 2638)
    1. Blank Input for Wind Uplift Force Direction

      Starting with version 9.2, we allow the wind uplift forces to be entered for each wind direction separately, but by default, when an uplift load was selected, nothing appeared in the wind direction box. If you proceeded to enter the loads without selecting a direction, or both directions, then the wind uplift did not get included in the combined hold-down forces, and the separate wind uplift component of the hold-down force that was shown in elevation view and in the output report was unreliable.

      In addition, a load entered with blank direction showed up as blank in the Load Input dialog edit field, E->W in the load list, and Both directions in the load list in the output report. In fact it acted as none of these

      The default showing in this box is now “Both Ways”, and it is never allowed to be blank.

    2. Display of Uplift Loads Entered in Both Directions

      If a selection was made for the wind direction before adding the load, the combined hold-down forces were correct; however the uplift component appeared in elevation view for both directions, when it shouldn’t have.

      Different loads entered west to east and east to west (the usual case) were shown superimposed and thus garbled in plan view and in elevation view, along with the uplift components of the hold-downs.

      These problems have been corrected.

    3. Editing Wind Uplift Loads

      The following problems in the Load Input screen used for editing existing loads were corrected:

      All loads showed up in the load list as E->W, even if they were W-> E or Both Ways.

      An E->W load selected showed the direction in the edit box as blank.

  6. Accumulation of Direct Shearline Force for Seismic Design (Bug 2630)

    Starting with Shearwalls version 9, when a seismic direct shearline force was applied to a shearline, the program did not include that force in the rigid diaphragm design shear. The direct forces did show up in both plan view and elevation view, but not accumulated with forces on the line from the generated loads, so the numbers overlap. This has been corrected and the seismic direct shearline forces are once again included in the design shear force.

  7. Nonsense Hold-down Values at Gable End of Monoslope Roof (Bug 2509)

    When there is a monoslope roof, the hold-down calculations at the gable end yielded nonsense values indicative of a divide-by-zero situation. These hold-down forces appeared in all output and were used in the design of hold-downs at these locations. This has been corrected.

  8. Shear Deflection for Custom Sheathing Thicknesses (Bug 2585)

    If you type in a sheathing thickness rather than a standard one, the shear deflection was set to zero. This has been corrected and the program now uses the deflection for the next smallest sheathing

See Also

Version 9.3

Input

Graphics and Output

Program Operation

Version 9.3.2