Last Updated: 2020.5
NOTE: The above
Wind
Basic Wind Speed (V): corresponds corresponds to a 3-sec gust speed at 33 ft (10 m) above the ground in Exposure Category C. Will be affected by patching for Metric vessels, the conversion from old to current will be to multiply the old value by 0.2778 and then round up to the nearest whole number. Units on form will be mph in Customary and m/s in Metric.
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Roof Height of Supporting Structure (h): It It is the mean roof height of a building or height of other structure. It is a new field and will default to 0.
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Building Damping Coefficient: This This is a field for skirt supports only.
Seismic
0.2 S Spectral Response Acceleration (Ss): mapped MCER , 5 percent damped, spectral response acceleration parameter at short periods.
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Response Modification Factor (R): response modification coefficient as given by the specific Seismic Code.
TL: long-period transition period as defined by the Seismic Code, only affects skirt supported vessels.
Fa: short-period site coefficient (at 0.2 s-period) to be used if the value cannot be determined by tables in the referenced code.
Fv: long long-period site coefficient (at 1.0 s-period) to be used if the value cannot be determined by tables in the referenced code.
Skirt is sensitive to buckling: This checkbox only applies to Skirt supports. And if checked it will adjust the CR-I value to a greater value in some cases resulting in a higher load value.
ap: the the amplification factor related to the response of a system or component as affected by the type of seismic attachment; this is only used for vessels designs as supported by another structure.
Use ASCE 15.4.1 Step 2 exception: Checking this box will invoke the exception as described in ASCE and will adjust the Cs calculation and typically results in a lower load value.
z: height in structure of point of attachment of component with respect to the base, the ratio of z/h is what is used in the calculations and so specific units are not required as long as z and h are input in the same units; a z/h ratio of 1 is conservative. This is only used for vessels designs as supported by another structure.
Supported by another structure: This has an effect on what Seismic calculations are performed. When checked the vessel will use calculations treating it as a piece of equipment inside a larger structure or building instead of as a self-supporting vessel. This typically results in larger loads.
h: average roof height of structure with respect to the base, the ratio of z/h is what is used in the calculations and so specific units are not required as long as z and h are input in the same units; a z/h ratio of 1 is conservative. This is only used for vessels designs as supported by another structure.
Force Ip to 1.5: Checking this box will force set the component importance factor to 1.5. This is only used for vessels designs as supported by another structure.
Consider Vertical Seismic Effect: This drop-down will affect the Cev values used in the Seismic calculations: This option allows the user to choose whether to evaluate vertical seismic effect and defaults to checked as the building codes required the vertical effect in most scenarios. When unmarked, the Cev value is set to zero.
Min. Weight Fraction as Lateral Load: This box gives the user the capability of setting a certain percentage of the weight as the minimum lateral load used in support analysis. The input is a fraction in decimal form. This field defaults as zero.
Tv: This is a user input for the ASCE 7-16 code year. The default is set to 0.1 to give conservative estimations within the software. The user can input values but only the range from 0 to 2 is usable within the equations. Values outside of this range will be taken equal to the upper or lower bound.