Dynamic Load Cases

Eigen Solution

The Eigen Solution dialog box opens. Enter the Number of Periods Requested or accept the default value. The maximum number of periods that can be entered is 3 times the number of stories that include lateral members. The default value is either 9 or the maximum number of periods; whichever is smaller. See section 5.9 in the RAM Frame Manual for further discussion of the dynamic solution technique.

Note: Only one Eigen Solution load case is permitted per model.

Response Spectra

Setting	Description
Load Case	States the Label of the load case being defined.
Direction	Use the Direction box to indicate the direction of the force (X, Y, or both) by clicking on the corresponding box so that the box is marked. One load case will be generated for each direction at which the force acts.
Modal Combination	You may specify the technique to be used in the combination of the modal responses by choosing either SRSS or CQC. SRSS = Square - Root - Sum - of - the - Squares CQC = Complete Quadratic Combination See section 6.9.4 in the RAM Frame Manual for further discussion on modal combination methods.
Response Spectra File	You may select a response spectra file from the list provided. The list includes the Response Spectra Files provided with RAM Frame and user-created, custom files. For more information on creating custom tables, see the RAM Manager manual.
Damping Ratio	The specified Damping Ratio (modal damping / critical damping) is used for all modes in the CQC method. See the RAM Frame Manual for further discussion on modal combination methods.
Scale Factor	The Scale Factors are used to scale the spectrum acceleration values from the Response Spectra File in X and Y directions. Note that both X and Y directions require scale factors. For custom files, the scale factors are used to modify the spectrum intensity or to change the acceleration values to consistent units.
Eccentricity	To account for accidental torsion in response spectra analysis, the user may specify that the dynamic load cases are applied at n% eccentricity [n=5% for most US codes, 10% for NBC95 of Canada, or user specified in the Load-Mass dialog box]. RAM Frame will then carry four independent dynamic analyses by moving the center of masses by the subscribed eccentricities in + and - directions for both X and Y axis.

ASCE 7-10 / ASCE 7-05 Response Spectra

Setting	Description
Load Case	States the Label of the load case being defined.
Direction	Use the Direction box to indicate the direction of the force (X, Y, or both) by clicking on the corresponding box so that the box is marked. One load case will be generated for each direction at which the force acts.
Modal Combination	You may specify the technique to be used in the combination of the modal responses by choosing either SRSS or CQC. SRSS = Square - Root - Sum - of - the - Squares CQC = Complete Quadratic Combination See section 6.9.4 in the RAM Frame Manual for further discussion on modal combination methods.
Eccentricity	To account for accidental torsion in response spectra analysis, the user may specify that the dynamic load cases are applied at n% eccentricity [n=5% for most US codes, 10% for NBC95 of Canada, or user specified in the Load-Mass dialog box]. RAM Frame will then carry four independent dynamic analyses by moving the center of masses by the subscribed eccentricities in + and - directions for both X and Y axis.
Site Class	The Site Class is specified in IBC Table 1613.5.5. It is based on the Soil profile and properties.
Ss	Ss is the mapped spectral accelerations for short periods as determined in IBC Section 1613.5.1. Values are given in Figures 1613.5(1) through 1613.5(14)
S1	S1 is the mapped spectral accelerations for a 1-second period as determined in IBC Section 1613.5.1. Values are given in Figures 1613.5(1) through 1613.5(14)
TL	Long-period transition period(s) given in Figures from 22-15 to 22-20 in ASCE 7-05.
Damping Ratio	The specified Damping Ratio (modal damping / critical damping) is used for all modes in the CQC method. See the RAM Frame Manual for further discussion on modal combination methods.
Scale Factor	The Scale Factors are used to scale the spectrum acceleration values from the Response Spectra File in X and Y directions. Note that both X and Y directions require scale factors. For custom files, the scale factors are used to modify the spectrum intensity or to change the acceleration values to consistent units.

IBC 2003 Response Spectra

Setting	Description
Load Case	States the Label of the load case being defined.
Direction	Use the Direction box to indicate the direction of the force (X, Y, or both) by clicking on the corresponding box so that the box is marked. One load case will be generated for each direction at which the force acts.
Modal Combination	You may specify the technique to be used in the combination of the modal responses by choosing either SRSS or CQC. SRSS = Square - Root - Sum - of - the - Squares CQC = Complete Quadratic Combination See section 6.9.4 in the RAM Frame Manual for further discussion on modal combination methods.
Eccentricity	To account for accidental torsion in response spectra analysis, the user may specify that the dynamic load cases are applied at n% eccentricity [n=5% for most US codes, 10% for NBC95 of Canada, or user specified in the Load-Mass dialog box]. RAM Frame will then carry four independent dynamic analyses by moving the center of masses by the subscribed eccentricities in + and - directions for both X and Y axis.
Site Class	The Site Class is specified in IBC Table 1615.1.1. It is based on the Soil profile and properties.
Ss	Ss is the mapped spectral accelerations for short periods as determined in IBC Section 1615.1. Values are given in Figures 1615(1) through 1615(10).
S1	S1 is the mapped spectral accelerations for a 1-second period as determined in IBC Section 1615.1. Values are given in Figures 1615(1) through 1615(10).
Damping Ratio	The specified Damping Ratio (modal damping / critical damping) is used for all modes in the CQC method. See the RAM Frame Manual for further discussion on modal combination methods.
Scale Factor	The Scale Factors are used to scale the spectrum acceleration values from the Response Spectra File in X and Y directions. Note that both X and Y directions require scale factors. For custom files, the scale factors are used to modify the spectrum intensity or to change the acceleration values to consistent units.

China GB50011-2001 Response Spectra

Setting	Description
Load Case	States the Label of the load case being defined.
Direction	Use the Direction box to indicate the direction of the force (X, Y, or both) by clicking on the corresponding box so that the box is marked. One load case will be generated for each direction at which the force acts.
Modal Combination	You may specify the technique to be used in the combination of the modal responses by choosing either SRSS or CQC. SRSS = Square - Root - Sum - of - the - Squares CQC = Complete Quadratic Combination See section 6.9.4 in the RAM Frame Manual for further discussion on modal combination methods.
Eccentricity	To account for accidental torsion in response spectra analysis, the user may specify that the dynamic load cases are applied at n% eccentricity [n=5% for most US codes, 10% for NBC95 of Canada, or user specified in the Load-Mass dialog box]. RAM Frame will then carry four independent dynamic analyses by moving the center of masses by the subscribed eccentricities in + and - directions for both X and Y axis.
Damping Ratio	The specified Damping Ratio (modal damping / critical damping) is used for all modes in the CQC method. See the RAM Frame Manual for further discussion on modal combination methods.
Scale Factor	The Scale Factors are used to scale the spectrum acceleration values from the Response Spectra File in X and Y directions. Note that both X and Y directions require scale factors. For custom files, the scale factors are used to modify the spectrum intensity or to change the acceleration values to consistent units.
Structure Period	Structure periods can be automatically calculated by the program for both X and Y direction (note that the program considers period that is based on the Eigen mode (i.e., mode shape) with highest building mass participation). Or, the user can enter structure period for X and Y direction separately. Note that if the 1st option is chosen (Use Calculated T), then the period multiplier is directly applied to calculated period (by default, it is 1.0).
Earthquake Group	The following earthquake groups are available: 1, 2 and 3.
Earthquake Type	The following earthquake types are available : Frequent and Rare
Soil Site Class	The following soil site class are available: I, II, III, and IV
Fortification Intensity	The following fortification intensities are available: 6, 7, 7(0.15g), 8, 8(0.30g) and 9. Values with parenthesis are used for design basic acceleration of ground motion with 0.15g and 0.30g.

AS 1170.4-2007 Response Spectra

Setting

Description

Load Case

States the Label of the load case being defined.

Direction

Use the Direction box to indicate the direction of the force (X, Y, or both) by clicking on the corresponding box so that the box is marked. One load case will be generated for each direction at which the force acts.

Modal Combination

You may specify the technique to be used in the combination of the modal responses by choosing either SRSS or CQC.

SRSS = Square - Root - Sum - of - the - Squares
CQC = Complete Quadratic Combination

See section 6.9.4 in the RAM Frame Manual for further discussion on modal combination methods.

Eccentricity

To account for accidental torsion in response spectra analysis, the user may specify that the dynamic load cases are applied at n% eccentricity [n=5% for most US codes, 10% for NBC95 of Canada, or user specified in the Load-Mass dialog box]. RAM Frame will then carry four independent dynamic analyses by moving the center of masses by the subscribed eccentricities in + and - directions for both X and Y axis.

Building Seismic Properties group

Type values for both X and Y directions.

Setting	Description
Structural Ductility Factor (mu)	µ; Refer to Section 6.5 of the building code
Structural Performance Factor (Sp)	Refer to Section 6.5 of the building code

Site Hazard Factors

Setting	Description
Probability Factor (kp)	Refer to Section 3, Table 3.1 of the building code
Hazard Factor (Z)	Refer to Section 3, Table 3.2 of the building code

Site Sub-soil Class

Select one of the five different site sub-soil class: Ae. Be, Ce, De, or Ee

Damping Ratio

The specified Damping Ratio (modal damping / critical damping) is used for all modes in the CQC method. See the RAM Frame Manual for further discussion on modal combination methods.

Scale Factor

The Scale Factors are used to scale the spectrum acceleration values from the Response Spectra File in X and Y directions. Note that both X and Y directions require scale factors. For custom files, the scale factors are used to modify the spectrum intensity or to change the acceleration values to consistent units.

NBCC 2015 - Response Spectra

Setting

Description

Load Case

States the Label of the load case being defined.

Direction

Use the Direction box to indicate the direction of the force (X, Y, or both) by clicking on the corresponding box so that the box is marked. One load case will be generated for each direction at which the force acts.

Eccentricity

To account for accidental torsion in response spectra analysis, the user may specify that the dynamic load cases are applied at n% eccentricity [n=5% for most US codes, 10% for NBC95 of Canada, or user specified in the Load-Mass dialog box]. RAM Frame will then carry four independent dynamic analyses by moving the center of masses by the subscribed eccentricities in + and - directions for both X and Y axis.

Site Properties

Setting	Description
Site Class	Site classes of A, B, C, D and E are included.
Sa(0.2) / Sa(0.5) / Sa(1.0) / Sa(2.0)	Spectral acceleration values Sa of 0.2, 0.5, 1.0 and 2.0 seconds must be entered to define the design spectral acceleration curve.

Based on Site Class and values of SA(0.2) and Sa(1.0), the design spectral acceleration curve is generated as follows:

\begin{matrix} S (T) = \end{matrix} {\begin{matrix} F a S a (0.2) & T \leq 0.2 s \\ F v S a (0.5) or F a S a (0.2), whichever is smaller & T = 0.5 s \\ F v S a (1.0) & T = 1.0 s \\ F v S a (2.0) & T = 2.0 s \\ F v \frac{S a (2.0)}{2} & T \geq 4.0 s \end{matrix}

where Fα and Fv are determined according to Tables 4.1.8.4.B and 4.1.8.4.C, respectively. For intermediate values, linear interpolation is used.

Modal Combination

You may specify the technique to be used in the combination of the modal responses by choosing either SRSS or CQC.

SRSS = Square - Root - Sum - of - the - Squares
CQC = Complete Quadratic Combination

See section 6.9.4 in the RAM Frame Manual for further discussion on modal combination methods.

Damping Ratio

The specified Damping Ratio (modal damping / critical damping) is used for all modes in the CQC method. See the RAM Frame Manual for further discussion on modal combination methods.

Scale Factor

The Scale Factors are used to scale the spectrum acceleration values from the Response Spectra File in X and Y directions. Note that both X and Y directions require scale factors. For custom files, the scale factors are used to modify the spectrum intensity or to change the acceleration values to consistent units.

NBCC 2005 - Response Spectra

Setting

Description

Load Case

States the Label of the load case being defined.

Direction

Use the Direction box to indicate the direction of the force (X, Y, or both) by clicking on the corresponding box so that the box is marked. One load case will be generated for each direction at which the force acts.

Modal Combination

You may specify the technique to be used in the combination of the modal responses by choosing either SRSS or CQC.

SRSS = Square - Root - Sum - of - the - Squares
CQC = Complete Quadratic Combination

See section 6.9.4 in the RAM Frame Manual for further discussion on modal combination methods.

Eccentricity

To account for accidental torsion in response spectra analysis, the user may specify that the dynamic load cases are applied at n% eccentricity [n=5% for most US codes, 10% for NBC95 of Canada, or user specified in the Load-Mass dialog box]. RAM Frame will then carry four independent dynamic analyses by moving the center of masses by the subscribed eccentricities in + and - directions for both X and Y axis.

Scale Factor

The Scale Factors are used to scale the spectrum acceleration values from the Response Spectra File in X and Y directions. Note that both X and Y directions require scale factors. For custom files, the scale factors are used to modify the spectrum intensity or to change the acceleration values to consistent units.

Site Properties

Setting	Description
Site Class	Site classes of A, B, C, D and E are included.
Sa(0.2) / Sa(0.5) / Sa(1.0) / Sa(2.0)	Spectral acceleration values Sa of 0.2, 0.5, 1.0 and 2.0 seconds must be entered to define the design spectral acceleration curve.

Based on Site Class and values of SA(0.2) and Sa(1.0), the design spectral acceleration curve is generated as follows:

\begin{matrix} S (T) = \end{matrix} {\begin{matrix} F a S a (0.2) & T \leq 0.2 s \\ F v S a (0.5) or F a S a (0.2), whichever is smaller & T = 0.5 s \\ F v S a (1.0) & T = 1.0 s \\ F v S a (2.0) & T = 2.0 s \\ F v \frac{S a (2.0)}{2} & T \geq 4.0 s \end{matrix}

where Fα and Fv are determined according to Tables 4.1.8.4.B and 4.1.8.4.C, respectively. For intermediate values, linear interpolation is used.

Damping Ratio

The specified Damping Ratio (modal damping / critical damping) is used for all modes in the CQC method. See the RAM Frame Manual for further discussion on modal combination methods.

IS 1893 (Part 1): 2002, 5th Rev. / 2016, 6th Rev. - Response Spectra

Setting	Description
Load Case	States the Label of the load case being defined.
Direction	Use the Direction box to indicate the direction of the force (X, Y, or both) by clicking on the corresponding box so that the box is marked. One load case will be generated for each direction at which the force acts.
Eccentricity	To account for accidental torsion in response spectra analysis, the user may specify that the dynamic load cases are applied at n% eccentricity [n=5% for most US codes, 10% for NBC95 of Canada, or user specified in the Load-Mass dialog box]. RAM Frame will then carry four independent dynamic analyses by moving the center of masses by the subscribed eccentricities in + and - directions for both X and Y axis.
Modal Combination	You may specify the technique to be used in the combination of the modal responses by choosing either SRSS or CQC. SRSS = Square - Root - Sum - of - the - Squares CQC = Complete Quadratic Combination See section 6.9.4 in the RAM Frame Manual for further discussion on modal combination methods.
Soil Site Type	Select the applicable soil description. Type I (Rocky or Hard Soil) Type II (Medium Soil) Type III (Soft Soil)
Damping Ratio	The specified Damping Ratio (modal damping / critical damping) is used for all modes in the CQC method. See the RAM Frame Manual for further discussion on modal combination methods.
Scale Factor	The Scale Factors are used to scale the spectrum acceleration values from the Response Spectra File in X and Y directions. Note that both X and Y directions require scale factors. For custom files, the scale factors are used to modify the spectrum intensity or to change the acceleration values to consistent units.