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Pg 1 of 6Structural Design Optimization

CONNECTION STIFFNESS IMPLEMENTATION PROCEDUREFOR ETABS/SAP USERS

Modeling of Lateral Frames Using SidePlate® Connection Technology:

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The inherent SidePlate® connection stiffness can be implemented within ETABS or SAP by replacing the

beam and column stiffness with the SidePlate® stiffness. The SidePlate® connection provides a 100% rigid

panel zone at the column and increases the beam section properties for a distance of approximately the

beam depth (Db) beyond the face of the column. Refer to the SidePlate® Tech Tips document for a

description of the different SidePlate® connection types and general design guidelines.

Figure 1 - SidePlate® Bolted connection elevation Figure 2 - SidePlate® Bolted connection section

BEFORE YOU BEGIN: It is important to ensure that a "Standard Moment Connection" is applied to all lateral

beams before any non-prismatic sections are applied. To remove any RBS or SidePlate® built in features do as

follows: Select all moment frame beams > Assign > Frame > Moment Frame Beam Connection Type > Standard

Moment Connection > OK. Missing this step can result in inaccurate stiffness and/or stress results.

USING NON-PRISMATIC BEAM SECTIONS is the most accurate way of implementing the SidePlate®

connection properties in ETABS or SAP.

The stiffened SidePlate® section extends from column face to Dim A (shown in Figure 1). This stiffened

SidePlate® section, which consists of the physical side plates {A}, cover plates {B} and beam, has an

approximate moment of inertia (3) times that of the beam alone for SMF, IMF and OMF applications and (1)

times the moment of inertia of the beam for R=3 applications.D

b

Column

Beam

C ColL

100% RIGIDPanel Zone

Side plate {A}

Stiffened Region

Column/BeamSeparation

ELEVATION

Dim A

Dim

B

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Pg 1 of 6Structural Design Optimization

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STEP 1: CREATE THE SECTIONS FOR THE NON-PRISMATIC BEAM (I.E. XXSP) – 1 TOTAL PER

NON-PRISMATIC BEAM (SEE FIG. 3)

Click Define > Section Properties > Frame Sections > choose "Add New Property" > General

Make sure the steel material matches the steel frame members used.

This stiffened SidePlate® section is referred to as the SP section. Change the Section name to

represent the section + SP. (e.g. For W21X62, this section would be called W21X62SP.)

Update the section dimensions:

o Depth = (Dim B) per the SidePlate® Connection Properties document.

o Width = beam width (however does not affect the results, and may be the column width).

Open "Modify/Show Modifiers" and input connection properties per the SidePlate® Connection Properties

document.

Figure 3 - ETABS general section for non-prismatic beam sections

STEP 2: CREATE THE ACTUAL NON-PRISMATIC BEAMS

• Choose "Add New Property" > Nonprismatic

• Change section name to ‘sectionNPSP’ (e.g. W27x102NPSP)

• Change start section and end section to XXSP, which in this

case is the W27X102SP section. Input length = (Dim A) per the

SidePlate® Connection Properties document.

• SP section lengths are set to Absolute type and the beam

section in the middle is set to Proportional type (this accounts for

different bay widths in which this section may be used).

• All EI33 and EI22 Variations are set to Linear type.

Note: SidePlate® developed a tool to help our clients to easily

implement NP sections in ETABS. This tool allows the engineer

to perform Step 1 and Step 2 with a click of a button . Please

contact SidePlate at solutions@sideplate.com to request this tool. Figure 4 - ETABS non-prismatic sections

For more information: Toll Free 800 475 2077 Tel 949 238 8900 www.sideplate.com

Pg 1 of 6Structural Design Optimization

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STEP 3: MODEL SIDEPLATE ’S PANEL ZONE

• Select all moment frame beams and columns:

• Assign > Frame > End Length Offsets

• Rigid-zone factor = 1.0 > press OK.

(see Fig. 5)

Note: All SidePlate® full-scale steel moment frame testing has

demonstrated that the panel zone contributes very little to the

total overall drift. Thus, it has been deemed by the AISC

CPRP pre-qualification committee that the flexibility in the

panel zone is negligible and can be considered as 100% rigid.

Thus, it would be incorrect to utilize the ETABS Panel Zone

feature when modeling SidePlate®.

STEP 4: CONNECTION WEIGHT

To obtain the approximate connection weight for a specific project, simply email your ETABS model to

solutions@sideplate.com. One of our engineers will review the model for validation and reply with the

connection weight.

Figure 5 - ETABS end length offsets

IMPORTANT NOTE REGARDING THE SIDEPLATE BUILT IN FEATURE: Due to some recent

modifications in ETABS, it has been discovered that on several isolated instances the software may

incorrectly implement the increased stiffness of the SidePlate connection thus giving inaccurate results.

CSI is aware of the issue and is working diligently to correct this error. For this reason, SidePlate advises

our clients to avoid using the built in feature and to instead utilize non-prismatic beam sections as

described above. Please contact SidePlate® with any additional questions or concerns. CSI apologizes

for this inconvenience and will alert SidePlate as soon as it is fixed.

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