Under the

(1) General. In this document, the Nonlinear

Nonlinear Static Procedure, a model directly

Static Procedure involves the monotonic application

incorporating inelastic material response is displaced

of lateral forces or displacements to a nonlinear

to a target displacement, and resulting internal

mathematical model of a building until the

deformations and forces are determined.

The

displacement of the control node in the mathematical

nonlinear-load-deformation

characteristics

of

model exceeds a target displacement. For buildings

individual components and elements of the building

that are not symmetric about a plane perpendicular

are modeled directly. The mathematical model of

to the applied lateral loads, the lateral loads must be

the building is subjected to monotonically increasing

applied in both the positive and negative directions,

lateral forces or displacements until either a target

and the maximum forces and deformations used for

displacement is exceeded, or the building collapses.

design. The relation between base shear force and

The target displacement is intended to represent the

lateral displacement of the target node shall be

maximum displacement likely to be experienced

established for control node displacements ranging

during

the

design

earthquake.

The

target

between zero and 150 percent of the target

displacement, ***t, given by Equation 5-5. Acceptance

displacement may be calculated by any procedure

that accounts for the effects of nonlinear response on

criteria shall be based on those forces and

displacement amplitude; one rational procedure is

deformations

(in

components

and

elements)

presented in Paragraph 5-4f, and further described in

corresponding

to

a

minimum

horizontal

displacement of the control node equal to ***t,.

Paragraph 4-8b(3) and Table 4-7.

Because the

mathematical model accounts directly for effects of

Gravity loads shall be applied to appropriate

material inelastic response, the calculated internal

elements and components of the mathematical model

forces will be reasonable approximations of those

during the nonlinear analysis. The loads and load

expected during the design earthquake. The target

combination presented in ASCE 7, as appropriate,

displacement calculated using Equation 5-5 may be

shall be used to represent the gravity loads. The

unconservative if the strength ratio of Equation 5-6

analysis model shall be discretized in sufficient

exceeds five, or if the building is located in the near

detail to represent adequately the load-deformation

field of the causative fault. Results of the Nonlinear

response of each component along its length.

Static Procedure are to be checked using the

Particular attention should be paid to identifying

applicable acceptance criteria prescribed in Chapter

locations of inelastic action along the length of a

6, and provided in Chapter 7.

Calculated

component, as well as at its ends.

displacements and internal forces are to be compared

directly with the allowable values.

(2)

Control node.

The procedure requires

definition of the control node in a building. This

document considers the control node to be the center

of mass at the roof of a building.

The top of a

penthouse should not be considered as the roof. The

5-9

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