Flexcom > Data Inputs > $SHEAR7 > *SECTION COEFFICIENTS

Purpose

To assign SHEAR7 coefficients to element sets.

Theory

Refer to SHEAR7 Data Specification for further information on this feature. For more information, refer to the Shear7 User Guide which is available for download from the Shear7 Support web page.

Keyword Format

A block of two lines defining the section coefficients. The block may be repeated to allow for the specification of different coefficients to different sets.

Two lines that make up the block:

SET=Set Name

[Normal Added Mass][, Damping Coefficient 0][, Damping Coeffient 1] [, Damping Coeffient 2] [, Damping Coeffient 3] [, Damping Coeffient 4]

If not specified, the Normal Added Mass will default to that specified in the static model. Damping Coefficient 0 is the Reynolds Still Water Damping Coefficient which defaults to 1.0. This specification is required for SHEAR7 Version 4.8 and above. If this value is specified for older version of the software, the value will be ignored. Damping Coefficient 1 is the A/D Still Water Damping Coefficient which defaults to 0.20. Damping Coefficient 2 is the Low Relative Velocity (VR) Region Damping Coefficient which defaults to 0.18. Damping Coefficient 3 is the High Relative Velocity (VR) Region Damping Coefficient which defaults to 0.20. Damping Coefficient 4 is the Axial Flow Region which defaults to 0.0. This specification is required for SHEAR7 Version 4.8 and above. If this value is specified for older version of the software, the value will be ignored.

Table Input

Input:	Description
Set Name:	The element set to which the coefficients are to be assigned. This defaults to all elements.
Added Mass Coefficient:	The Normal Added Mass coefficient to be assigned to this set. If a value is not specified, the normal added mass coefficient specified in the Model section is used.
Damping Coefficient 0:	Reynolds Still Water Damping Coefficient to be assigned to this set. The default value for this coefficient is 1.0. See the SHEAR7 User Manual for further details. See Note (a) and (b).
Damping Coefficient 1:	A/D Still Water Damping Coefficient to be assigned to this set. The default value for this coefficient is 0.20. See the SHEAR7 User Manual for further details. See Note (a).
Damping Coefficient 2:	Low Relative Velocity (VR) Region Damping Coefficient to be assigned to this set. The default value for this coefficient is 0.18. See the SHEAR7 User Manual for further details. See Note (a).
Damping Coefficient 3:	High Relative Velocity (VR) Region Damping Coefficient to be assigned to this set. The default value for this coefficient is 0.20. See the SHEAR7 User Manual for further details. See Note (a).
Damping Coefficient 4:	Axial Flow Region Damping Coefficient to be assigned to this set. The default value for this coefficient is 0.0. See the SHEAR7 User Manual for further details. See Note (a) and (b).

Notes

(a)All default damping coefficients are based on SHEAR7’s recommendation for a bare riser.

(b)These coefficients were introduced in SHEAR7 Version 4.8. If these values are specified for old versions, the values will be ignored.