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A setting has been added to allow you to choose whether the points of zero moment (counterflexure) are to be used to delineate the unsupported length for the CL factor calculations in NDS 3.3.3.
The change we introduced with version 10.1 to no longer allow points of zero moment to be used to delineate the unsupported length for KL factor caused large changes in strength of certain multi-span applications, and was questioned by several users. We believe that the decision to make this change was based on sound research, and this is reflected for example in the change to the calculation example 7.5 in the Canadian Wood Council’s Introduction to Wood Design for the 2011 edition. However, at the end of this example, a note says, In some cases engineering may choose an alternate approach… based on .. the distance between support and zero moment or the distance between zero moments. It then refers to Example 13.3 which uses this approach.
For this reason we added an option to allow you to use zero moments.
A Design setting has been added called. Unsupported length Lu ends at points of zero moment (counterflexure).
This setting defaults to unchecked. It is saved with the project file. If a file from a previous version is opened, the setting takes on whatever value is in the Design Settings when the file is opened.
If checked, for each span the program determines the lowest of
and uses this as the unsupported length. Note that this differs from the implementation before version10.1 which determined this distance only in the vicinity of the critical design moment value. Refer to the discussion in Bug 2708 under version 10.1 below.
For roof I-joists only, the program applied a 10% reduction to stiffness EI to approximate the effect of shear deflection, but also calculated the change needed in EI to implement shear deflection, compounding the effect of shear deflection. This has been corrected by removing the 10% reduction.
The program now adds a 10% increase in stiffness for floor I-joists to approximate the effects of composite action with the floor sheathing. Customized versions of WoodWorks Sizer for proprietary I-joist manufacturers such as Nordic Engineered Wood and Web Joist include detailed calculations of composite action.
The modified EI for shear deflection and composite action is now shown in the Additional Data of the Design Check report.
In reporting some design values for multi-ply members with a custom section, the program is applying the plies twice, so that values such as section areas, section modulus, S, etc. were mistakenly multiplied by a factor equalling the number of plies.
This caused the errors listed below in the design forces, design resistances, or other outputs. Note that these errors were only in the reporting of the design values and design ratios; the program would not issue a warning message based on the erroneous output showing a design failure, nor would it neglect to include a passing member in the list of suggested sections for this reason.
Note too that this occurs only in the case that you type in your own section, such as 2.5 x 5 rather than using a standard section like 2 x 6, and are using a multi-ply material such as Lumber n-ply, which is a somewhat unusual combination of circumstances.
The following problems entered the program with Version 9.2 and have been corrected for version 10.2:
The design stresses for shear, fv, axial compression, fc, axial bearing, fc*, and axial tension ft , weak axis moment fby shown in the Analysis column of the Analysis vs. Allowable Stress table were divided by the number of plies, so that the force shown was less than the one actually used for design by a factor of 1/plies. The design ratio shown used the erroneous value for stress, so that a failing design ratio could be shown for a section that actually passed.
The magnitude of the self-weight shown in the load list was greater than the actual load list by the number of plies. This only occurred in the load list shown in the Design Check report, not in the Analysis or Design Summary reports.
In the section under Critical Load Combinations, where the design force V is output, it is larger than it should be by a force equalling the number of plies.
In the CALCULATIONS section, the weak-axis Deflection Eiy is multiplied by the number of plies squared.
For weak axis design with multi-ply sections, the program was using an EI value for deflection that was less than it should be by the number of plies squared. This resulted much larger than expected deflections. This has been corrected.
For y-axis moment design, the section modulus S was mistakenly divided by the number of plies. As this value is used to convert the bending moment force Mf to the bending stress fb, the stress used for design calculations is higher than it should be by a factor equalling the number of plies.
This problem occurred for beams, laterally loaded columns and for combined axial and bending design of columns, and has been corrected.
Starting with version 9, when the lower end of the range of widths or the range of depths is unknown, and the upper end is known, but too small to allow for a successful design, the program searches past the upper end and finds a design. This has been the corrected and the program now reports that no design was found.
Notches were designed as though they were in tension for all load combinations if the notch was in tension for the last load combination in the list of load combinations. This has been corrected and the program now chooses the design routine for notches based on the stress conditions for the load combination being examined.
The default maximum lamination width for members greater then 10.75" was the width of the member, rather than the 10.75" given in 5.3.6 for volume factor C. This value was also used as the lamination width when performing the design search for unknown section size. This has been corrected and 10.75 is used as both the default and when searching through sections greater than 10.75".
The database editor program now allows you to view both Post and Timber and Beam and Stringer sets of properties for columns in the same way you previously could only for beams.
Since columns with rectangular profiles are somewhat uncommon they are not part of the standard database, so it was not possible in WoodWorks to design for these materials except via a custom section. Now you can create a custom column database that includes Beam and Stringer sizes.
Occasionally, the eccentricity for custom sections when auto-eccentricity is selected was set to zero rather than the calculated auto-eccentricity. This has been corrected and the program now always uses the specified proportion of member width or depth for auto- eccentricity of custom sections.
The "Auto-eccentricity" feature has been changed such that it applies to all loads rather than the currently selected loads, so that you do not have to set this checkbox for each load on the member. In most cases, when an eccentricity that is a percentage of member width is applied, it is required to be applied to all loads.
The symbols for IBC 722.6.3 fire procedure were from the original AWC technical paper 10, not the IBC. It now shows Z instead of z, and "Moment ratio" instead of r.
The fire resistance rating is now reported as 45 min, 1 h, 1.5 h, and 2 h instead of 45 min, 60 min, 90 min, and 120 min
In the Additional Data section of the program, the units displayed for the EIy value were in imperial when metric units had been selected for display. This has been corrected.
Pressing the "Repeating point load..." button in Loads View would cause Sizer to crash if the Show Loads view in a pop-up window setting is turned on. This has been corrected. Only a small minority of users require this setting to be turned on.
The message that appears when you press the button Apply options to Concept Mode that appears in the Load Input view, now refers to both Beam view and Column view. Previously it referred only to Beam view even if you pressed the button in Column Loads view.
The parallel strand lumber (PSL) material has been removed from the program, as it is a proprietary material of Weyerhaeuser and there is no agreement between CWC and Weyerhaeuser to continue software support for this product.
A digital signature verifying the reliability of the software publisher has been added to the Sizer stand-alone installation, so that disconcerting messages about the software no longer appear when downloading and installing.