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Update 1 to Sizer 2019 (Version 12.1) released on May 25, 2020.
The following problems regarding lateral stability calculations for built-up columns for axial compression design from NDS 15.3.1.2 were introduced with version 12.0 and have been corrected.
The program was using the single ply width in calculating the slenderness ratio le/b when checking against the allowable limit of 50 from NDS 15.3.2.3, although full member width should be used .
As a result, for a 10-foot column with 3-2x6 plies, the slenderness ratio was calculated as 80, causing the column to fail, when it should have been 26.7 and pass.
When the member incorrectly failed for this reason, a screen warning message appears, a red failure warning appears in the design check giving "Axial due to slenderness as the reason, and the axial compression line and combined axial and bending lines indicate the reason for failure. These messages refer to the identical requirement for solid columns from NDS 3.7.1.4.
Note that single-ply width is still checked to determine whether it the strength Fc’ is greater than for single ply than from multi-ply, as per 15.3.2.2 and this cannot be taken advantage of if the slenderness ratio using single-ply width is over 50. The problem was that it was indicating a design failure rather than merely not applying the advantage if it exists.
In the calculation of the Column Stability factor CP, if the slenderness ratio was greater in the width b direction than the depth d direction, the program used the slenderness ratio calculated for the d direction, and multiplied the result by the Kf factor ordinarily applied to the b direction, instead of using the slenderness factor calculated for the b direction. This typically caused the CP factor to be greater than it should be and overestimated the strength of the column.
In the example from the previous sub-item, the Column Stability Factor CP is shown 0.351 when it should have been 0.261.
If the slenderness ratio in the d direction was greater than that in the b direction, the program behaved as expected.
The letters "SP "have been removed from all the grade combination names for Glulam-Uniform Southern Pine columns and beams, because roughly half of the names were longer than permissible in Sizer. For example, 48 1:10 (N2D10) replaces 48 1:10 (SP N2D10).
Selection of one of these combinations in any program mode would cause arcane warning messages to appear and eventually the program would crash when running design or performing other input operations.
In the analysis of user-applied moments to right cantilever beam spans and columns with a fixed base and free top, the program was subtracting rather than adding the "fixed-end" deflection to the deflection due to rotation at supports.
As a result, downward deflections at the cantilever can be significantly lower than they should be, so that the maximum deflection that is compared to the deflection limit in the design of the member is too low. For beams that experience uplift at the cantilever, this created larger-than-expected deflections.
For columns, this caused the deflection due to the moment to be applied on the opposite side of the column than it should, creating inaccuracies when combined with deflections from other sources.
As an example, for a beam with a 6-meter middle span and a 2-meter cantilevers on each side and 10 kN-m applied moment at each end of the beam, the cantilever deflections were 3.6 mm on the right end and 10.9 mm on the left end, although these should be the same.
The incorrect deflections could be seen in the Analysis diagrams and in the maximum deflection shown in the Design Check report,and have now been corrected.
Deflections due to applied moments on a left-end cantilever, or other column fixity conditions, were correct.
The program includes the April 2020 update of the Simpson hanger database. Previously the July 2019 version was in use.
Changes described below have been made to load combination descriptors such as D+.75(L+S) that appear in the following places
The compressed format of the descriptors has been expanded to make them the same as they appear in the ASCE 7 and IBC design codes, by adding spaces between symbols and adding a leading zero before factors that are less than 1.0. What was formerly D+.75(L+S) now appears as D + 0.75(L + S)
The compressed descriptor still appears if it is necessary to reduce the length of a long, patterned combination in the Analysis output report, however this rarely occurs.
When a patterned snow load is the only load in a load combination, the combination was represented by the single lower-case letter "s" instead of the usual upper-case "S". It is now S, but the lower-case s is still used in the pattern description for the half-loaded spans, so that what was previously s (pattern: sS) is now S (pattern: sS).
The program now shows the clause reference numbers 2.4 for ASCE 7 and 1604.3.2 of IBC in the headers to the lists of load combinations in the Analysis results and the Design Check. It also indicates that the ASCE combinations are "Basic" (as opposed to "Strength").
The following problems regarding the display of data in the Additional Data section of the Design Check output were corrected.
In cases where the slenderness ratio for the calculation of the combined axial and bending check is not calculated because the slenderness ratio fails, in the Emin’ row of the Factors table , the unfactored buckling modulus Emin was was shown as 0.00 million instead of the value corresponding to the material for the member. This has been corrected.
For members with an oblique angle, the symbol e06 representing 106 was not shown in the after the weak axis bending stiffness EIy. The major axis bending stiffness EI was shown as expected.