[GEN] Steel Structure

0. Contents 

1. Summary

Steel Building

1-1 Structural Plans & Section

Structural Plan of the lower part (2~4F)

Structural Plan of the upper part (5~Roof)

The cross section (Section–②)

Applied Codes

• Applied Load / UBC(1997)

• Steel Design Code / AISC(14th)-LRFD10

• SRC Design Code / SSRC79

Used Materials

• Beam, Brace : A36

• Column:  A572-50, Concrete Grade C4000

Applied Loads

• Gravity loads

• Wind loads

- Basic Wind Speed : 80 mph

- Exposure Category : C

- Importance Factor : 1.0

- Pressure Coefficient : 1.3

• Seismic loads

- Seismic Zone Factor : Z = 1 (0.075)

- Importance Factor : 1.0

- Soil Coefficient : Sc

- Height of the building : Hn = 64 m

- Width of the building : Bx = 70.58 m, By = 48.95 m

- Response Modification Coefficient

Rx : 4.2 (Steel with steel OMRF)
Ry : 4.2 (Steel with steel OMRF)

• Unit Load Cases

2. Structural Modeling

2-1 Initial Window & Unit System Setting

File > New Project

File > Save (Steel)

Tools > Setting > Unit System or Status Bar

Length > m ; Force > N

Point Grid (off), Point Grid Snap (off), Line Grid Snap (off)

Initial Window Setting

2-2 Input Material Property & Section Data

Used material properties

Properties > Material > Material Properties

Name > Girder ; Type > Steel

Standard > ASTM(S) ; DB > A36

Name > Steel Column ; Type > Steel

Standard > ASTM(S) ; DB > A572-50

Name > SRC Column ; Type > SRC

Steel Standard > ASTM(S) ; DB > A572-50

Concrete Standard > ASTM(RC) ; DB > Grade C4000

Name > Brace ; Type > Steel

Standard > ASTM(S) ; DB > A36 .

Input material properties

Input the section data of the lower part girders

2-3 Input the 2nd floor Elements

Hidden (on), Node Number (on), Element Number (on)

Structure > Wizard > Base Structure > Frame

Input tab

X Coord. / Distance > 12 ; Repeat > 3

Z Coord./ Distance > 10.8 ; Repeat > 2

Z Coord./ Distance > 6 ; Repeat > 1

Z Coord./ Distance > 10.8 ; Repeat > 1

Edit tab

Beta Angle > 90 Deg.

Material > 1 ; Section > 221

Click .

Insert tab

Insert Point > 0, 0, 6

Rotations / Alpha > -90 .

Click .

 Zoom Fit

Create the 2nd floor elements using Frame Wizard

Node/Element > Elements > Create Element

Material Name > 1:Girder

Section Name > 226:SG6

Nodal Connectivity > 2, 5

Material Name > 1:Girder

Section Name > 222:SG2

Nodal Connectivity > Element 33 (Refer to Figure below)

Material Name > 1:Girder

Section Name > 231:SB1

Nodal Connectivity > Element 36 (Refer to Figure below)

Modify the 2nd floor elements

Top View

Select Window (Node 1)

Select Element 1, 16

Click Delete key

Display > Node > Node Number (off)

Tree Menu > Works tab

Select Single (8, 11, 34, 35, 37, 38)

Display > Property > Property Name (on)

Properties > Section > 222:SG2 (Drag & Drop)

Similarly change properties of SG1 to SG3A, SG4 & SG5 by Drag & Drop

Change the section numbers using Drag & Drop

2-4 UCS & Line Grid Setting

Node Number (on)

Display > Property > Property Name (off)

X-Y

Coordinates Origin > 36, 10.8, 6 (Node 8)
Angle > -30

Define Line Grid

Grid Name > Skew Plane

X-Grid Lines

Line > 2@12 .

Y-Grid Lines

Levels > -10.8, 2@10.8, 6, 10.8

Add/Modify Grid Lines

Zoom Fit (on), Line Grid Snap (on)

Define the grid lines

UCS & Line Grid setting

2-5 Create Elements of the Skewed Part

Node/Elements > Elements > Create Elements

Section Name > 221:SG1

Nodal Connectivity > Node 4 & corner of Line Grid

(Refer to ① of Figure below)

Create the Remainders (Refer to Figure below)

Input SG1 of the 2nd floor of the skewed part

Input the beam element of the 2nd floor of the skewed part

Select Single (unnecessary node & element; ① of Figure above)

Delete

Display

GCS (on), Line Grid (off), Line Grid Snap (off)

2-6 Input the Beam End Release Conditions

Display > Property > Property Name (on)

Select Single (SB1-element 36)

Boundary > Release/Offset >

Beam End Release (Refer to ① of Figure below)

Input the Beam End Release condition

The following column section data have been inputted in the file Steel(import).mgb

Column Section Data (1)

Column Section Data (2)

Typical method for inputting SRC sections :

Properties > Section > Section Properties

Add > SRC tab

Section ID > 101 ; Name > C1

Shape > Rect-IBeam

Concrete Data

HC > 0.7 ; BC > 0.7

Steel Data / DB > AISC

Steel Name > W 18×258

Material >

Concrete Material > DB > ASTM(RC)

Concrete Material / Name > Grade C4000

Steel Material > DB > ASTM(S)

Steel Material / Name > A572-50

Replace steel (on) ; Shear Deformation (on)

Input SRC Sections

Properties > Section > Section Properties > (① of Figure below)

Application folder > Steel(import).mgb

Import the column section data >

(Refer to Figure below)

Section data before Import

Input the section data using import function

2-7 Input Columns

Redraw

Node Number (on)

Display > Property > Property Name (off)

Iso View, Rotate Dynamic Zoom Fit (Refer to Figure below)

Select All

Unselect Window (Node 23, 24)

Node/Element > Elements > Extrude Elements

Extrude Type > Node → Line Element

Reverse I-J (on) ; Element Type > Beam

Material > 3 : SRC Column ; Section > 101 : C1

Generation Type > Translate ; Translate > Equal Distance

Beta angle > 0 ; Number of Times > 1

dx, dy, dz > 0, 0, -6

Display > Element > Local Direction (on)

Display > Element > Local Direction (off)

Create the columns of the 1st floor

Select Recent Entities (Columns)

Node/Element > Elements > Change Element Parameters

Parameter Type > Element Local Axis

Mode > Assign > Beta Angle > 90

Select Previous

Unselect Polygon (Columns with Beta Angle = 90°)

Beta Angle > 60

Select Single (Refer to ① of Figure below)

Assign > Beta Angle > -30

Unselect Polygon

Status bar > Filter > z (Columns)

Select All

Unselect Polygon (Columns) (Refer to Figure below)

Tree Menu > Works tab

Properties > Material > 2 : Steel Column (Drag & Drop)

Select All, Active, Node Number (off)

Display > Property > Property Name (on)

Select Single (Elements 83, 84) (Refer to Figure below)

Properties > Section > 151 : C1A (Drag & Drop)

Modify the others in the same way

Active All

Modify beta angles and material properties

Modify the column number using Drag & Drop

2-8 Input the Diagonal Elements

Section list of the diagonal elements

Input the Brace section data

Shrink (off)

Zoom Window (core part)

Node Number (on) , Element Number (on)

Node/Element > Elements > Create Elements

Element Type > Truss

Material Name > 4 : Brace

Section Name > 1001 : BR1

Nodal Connectivity > X-directional Braces (Refer to Figure below)

Section No. > 2001:BR2

Nodal Connectivity > Y-directional Braces (Refer to Figure below)

Input the Braces

2-9 Building Generation

Auto Fitting (on)

Node Number (off), Elements Number (off)

Status bar > Filter > none

Select All

Structure > Building > Control Data > Building Generation

Building Generation > Number of Copies > 2

Distance(Global Z) > 5 ; Operations >

Building Generation > Number of Copies > 6

Distance(Global Z) > 3.8 ; Operations >

Building Generation > Number of Copies > 6

Distance(Global Z) > 4.2 ; Operations >

Building Generation Table >

Insert the increment of the section numbers (Refer to Figure below)

Copy Element Attributes (on) >

Boundaries > Beam Release (on)    

Building Generation Table

Select Plane

XY Plane > Z Position > 64   

Active

Display > Boundary > Beam End release Symbol (on)

Display > Boundary > Beam End release Symbol (off)

Building Generation

2-10 Modify the upper part of the model

Sections of the upper part beams/girders

Active All, Top View

Select Polygon + Ctrl key in Keyboard (Top View of Figure below)

Front View

Unselect Window (Front View of Figure below)

Iso View

Delete Key in Keyboard (Selected Nodes & Elements)

Top view

Front view

Select the non-existent elements

Select-Identity Element

Select Type > Section

List > 243 ,

Right View

Unselect Window (Refer to Figure below)

Iso View

Tree Menu > Works tab

Properties>Section > 523:SG3 (Drag & Drop)

Select-Identity Element

Select Type > Section

List > 224 : SG4 ,

Top View

Unselect Window (Refer to Figure below)

Tree Menu/ Works tab

Properties > Section > 525:SG5 (Drag & Drop)

Iso View

Right View

Iso View

Modify the model using Unselect Window and Works Tree

Modify the model using Unselect Window

Modify the upper part of the model

2-11 Input Story Data

Structure > Building > Control Data > Story

Story Data

2-12 Input the Cantilever Beams

Structure > UCS/Plan > Named Plane

Plane Name > B

Plane Type > X-Z Plane

Y Position > 10.8

Select All

Active Identity > Named Plane > B

, 

 Display > Node > Story Name (on)
Display > Boundary > Beam End release Symbol (on) 

Activate the Named Plane

Node/Element > Elements > Extrude Elements

Extrude Type > Node → Line Element > Reverse I-J (on)

Element Type > Beam ; Material > 1:Girder

Section > 571:SCG1

Equal Distance > dx, dy, dz > 0, -1.2, 0

Number of Times > 1

Select Polygon (Nodes over the 5th Floor)

Node/Element > Elements >  Create Elements

Extrude Type > General beam/Tapered beam

Material > 1:Girder ; Section No. > 532:SB2

Zoom Window (the grid of the 5th Floor)

Nodal Connectivity > 637

Zoom Fit

Zoom Window (the grid of the 5th Floor)

Zoom Window (off)

Nodal Connectivity > 637, 640

Input the Cantilever Beam

Zoom Fit

Select Recent Entities

Boundary > Release/Offset > Beam End Release

Select Previous

Node/Element > Elements > Translate Elements

Translation > Unequal Distance

Axis > Z

Distances > 5@3.8, 6@4.2

Copy Node Attributes (on)

Copy Element Attributes (on)

Copy the outer Cantilever Beam

2-13 Input the Boundary Conditions

 Active All

Display > Node > Story Name (on)

Select Plane

XY Plane > Z Position > 0

Boundary > Supports > Define Supports

D-All (on) ; R-All (on)

Input the Support Condition of the structure

3. Input Loads

3-1 Load Cases Setting

Load > Static Load Cases

Input as Figure below

Static unit load case setting

3-2 Input Self-weight

Refer to other “Tutorials”.

3-3 Input the Floor Loads

Load > Static Loads > Initial Forces/Misc. > Assign Floor Loads

Load Type >

Define Floor Load Type (Refer to Figure below)

Refer to “Applied Loads” on page 5.

Define Floor Load Type

Active Identity

Story > 2F +Below (on)

,

Node Number (on)

Hidden (off)

Angle View

Horizontal > 50 ; Vertical > 60

Load > Static Loads > Initial Forces/Misc. > Assign Floor Loads

Load Type > Shop

Distribution Type > One Way ; Load Angle (A1) > 0

No. of Sub Beams > 3 ; Sub Beam Angle (A2) > 90

Unit Self Weight > 883 N/m ; Copy Floor Load (on)

Load Direction > Global Z ; Projection > Yes

Axis > Z ; Distances > 5

Nodes Defining Loading Area > 4,12, 9, 5, 2, 4

Input the Floor Loads

Nodes Defining Loading Area > 17, 13, 16, 20, 17

Nodes Defining Loading Area > 25, 28, 27, 8, 4, 25

Nodes Defining Loading Area > 30, 32, 31, 29, 30

Input the Floor Loads of the skewed part

Load Angle(A1) > 90

Sub-Beam Angle(A2) > 0

Nodes Defining Loading Area > 12, 27, 8, 12

Nodes Defining Loading Area > 20, 31, 29, 16, 20

Display > Load > Floor Load Name (on)

Confirm the inputted floor loads by Floor Load Name

No. of Sub Beams > 1

Nodes Defining Loading Area > 16, 29, 27, 12, 16

Nodes Defining Loading Area > 13, 14,10, 9, 13

Nodes Defining Loading Area > 15, 16, 12, 11, 15

Nodes Defining Loading Area > 29, 30, 28, 27, 29

No. of Sub Beams > 0

Nodes Defining Loading Area > 22, 21, 23, 24, 22

Active All

Confirm the inputted floor loads by Floor Load Name

Active Identity

Story > 4F +Below (on)
,

Display > Load > Floor Load Name (off)

Load Type > Office

Distribution Type > One Way

Load Angle (A1) > 90

No. of Sub Beams > 3

Sub-Beam Angle (A2) > 0

Unit Self Weight > 883 N/m

Copy Floor Load (on) ; Axis > z

Distances > 6@3.8, 5@4.2

Nodes Defining Loading Area > 124, 127, 123, 120, 124

Input the others in the same way (Refer to Figure below)

Node Number (off)

Active All, Front View

Tree Menu > Works tab

Loading Plan of the upper part over the 4th floor

Confirm the inputted floor loads on the upper Office

Active Identity

Story > 4F +Below (on)
,

Angle View

Horizontal > 50 ; Vertical > 60

Zoom Fit

Load Type > roof ; Description > 4F roof

Copy Floor Load (off)

Nodes Defining Loading Area > Roof Loads

* Notice: Load Angle, Sub-Beam Angle, Number of Sub Beams

Input the 4th floor loads

Confirm the inputted loads by Works Tree

Active Identity

Story > 5F +Below (on)
,

Load Type > Office

Distribution Type > One Way

No. of Sub Beams > 0

Description > Delete

Copy Floor Load (on)

Z Axis Distances > 5@3.8, 5@4.2

Nodes Defining Loading Area > Cantilever

*Consider Load Angle (A1)

Active Identity

Story > 15F +Below (on)

Input the Floor Loads of the upper part cantilever

Active Identity

Story > Roof +Below (on)
,

Load Type > roof

No. of Sub Beams > 3

Copy Floor Load (off)

Nodes Defining Loading Area > Roof Floor

Cantilever portion :

No. of Sub Beams > 0

Active All

Assign Floor Loads >

Floor Load Table > (Refer to Figure below)

Input the floor loads of the roof

Floor Load Table

3-4 Input the Wind Loads

Structure > Building > Control Data > Story

Wind tab (① of Figure below)

Story Data

Load > Lateral Loads > Wind Loads

Load Case Name > WX    Wind Load Code > UBC(1997)

Projected Area Method > (on) ;

Exposure Category > C ; Basic Wind Speed > 80

Importance Factor > 1 ; Pressure Coefficient > 1.3

Scale Factor in Global Y > 1 ; Scale Factor in Global Y > 0

Story Shear (GL) > 3241920.0 N   

Load Case Name > WY    Wind Load Code > UBC(1997)

Projected Area Method > (on) ;

Exposure Category > C ; Basic Wind Speed > 80

Importance Factor > 1 ; Pressure Coefficient > 1.3

Scale Factor in Global X > 0 ; Scale Factor in Global Y > 1

Story Shear (GL) > 4212477.0 N

Dialog box to input the wind load

Wind Load Profile

Wind loads calculation

3-5 Input the Response Spectrum Analysis Conditions

Structure > Type > Structure Type

Converting Type of Model weight to Masses > Convert to X, Y

Gravity Acceleration > 9.806

Align Top of Beam Section to Floor(X-Y Plane) for Panel

Zone Effect/Display (on)

Load > Structure Loads/Masses > Nodal Masses > Loads to Masses

Mass Direction > X, Y

Load Type for Converting > all (on)

Load Case > DL ; Scale Factor > 1   

Query > Story Mass Table

Create the mass data automatically

Story Mass Table

Load > Seismic > Response Spectrum Data > Response Spectrum Load Case

Number of Frequencies > 15 

Eigenvalue analysis conditions setting

Modal Combination Control >

Modal Combination Type > SRSS

Design Spectrum > UBC(1997)

Seismic Coefficients Calculation Option > Automatic (on)

Soil Profile Type (S) > Sc

Seismic Zone Factor (Z) > 1 (0.075)

Seismic Coefficient (Ca) > 0.09

Seismic Coefficient (Cv) > 0.13

Max. Period > 10 (sec)

Scale Factor (IE/R) > 0.238 (Refer to Figure below)

Assign the method of the mode combination

Dialog box to create the Design Spectrum automatically

Load > Seismic > Response Spectrum Data > Response Spectrum Load Case

Load Case Name > RX

Direction > X-Y

Excitation Angle > 0

Scale Factor > 1

Period Modification Factor > 1

Function Name > UBC1997 (on)

Operations >

Load Case Name > RY

Excitation Angle > 90

Operations >

Input the response spectrum load cases

4. Perform the Structural Analysis/Window Setting

Analysis > Perform Analysis

Toolbar setting to confirm the results

5. Confirm the Analysis Results

5-1 Examine Reactions

Tools > Setting > Unit System

Force > kN

Active Identity

Story > 2F ; +Below (on)

,

Results > Results > Reactions > Reaction Forces/Moments

Load Case/Combinations > ST : DL

Components > FZ

Type of Display > Values (on), Legend (on)

Values >

Decimal Points > 2

Results > Tables > Result Tables > Reaction

Load Combination > Self(ST) (on), DL(ST) (on), LL(ST) (on)

Confirm the reactions in the gravity direction

Reaction Table

5-2 Examine the Eigenvalue Analysis Results

Results > Tables > Result Tables > Vibration Mode Shape

Active Dialog >

Confirm the Eigenvalue analysis results

Model View tab

Iso View, Active All, Initial View

Results > Vibration Mode Shapes

Load Cases (Mode Numbers) > Mode 1

Components > Md-XYZ (on)

Type of Display > Mode Shape >

Mode Shape Scale Factor > 3.0

Animate (on) >

Animation Mode > Repeat Full Cycle

Record

Stop

Close

Vibration Mode Shapes

6. Steel Member Design

• Applied Design Code: AISC(14th)-LRFD10

6-1 Create the Load Combinations

All Windows except Model View >

Results > Combinations > Load Combination

Steel Design tab

Design Code > AISC(14th)-LRFD10

Scale Up Factor > 2.719, RX

Scale Up Factor > 2.504, RY

Input the Design Code & the Scale Up Factor

Create the load combinations

6-2 Input the Design Parameters

Design > General Design Parameter > Definition of Frame

X-Direction Frame > Braced I Non-sway

Y-Direction Frame > Braced I Non-sway

Design Type > 3-D (on)    

Definition of Frame

Initial View

Select Identity-Element

Select Type > Section

List > 221 : SG1

List > 226 : SG6

List > 521 : 5SG1

Design > General Design Parameter > Unbraced Length (L, Lb)

Add > Replace > (on)

Laterally Unbraced Length Lb > 4 

Input the remainders ; Refer to Table 1.5  

Input lateral unbraced lengths

Laterally Unbraced Length of the girders

Design > Design > Steel Design > Design Code

Design Code > AISC(14th)-LRFD10

All Beams/Girders are Laterally Braced (on) 

Select the design code

6-3 Steel Code Check

 Redraw

Design > Design > Steel Design > Steel Code Check

Result View Option > NG

(Refer to Figure below)

Property No. > 224

Select (SEL) W 30×116 (Refer to Figure below)

Select (SEL) > Property No. > 224

(Refer to Figure below)

Automatic Design Result Dialog box

Summary of Design Results

Change Steel Properties Dialog box

Design > Section > Section for Design

1001 > W 30×132 ; 1002 > W 12×50 ; 2001 > W 14×90 

Select Identity-Element > Select Type > Section

224(on), 1001(on), 1002(on), 2001(on)

Design > Design > Steel > Steel Code Check

Code Checking Result Dialog box after modifying the sections

Unselect All

Design > Design > Steel > Steel Code Check

Result View Option > All

Select (SEL) > 221

Ratio Limit > From > 0 ; To > 0.75

Modify section numbers using the design results

Model View tab

The right side of  Select Identity-Element (Refer to ① of Figure below)

[Ctrl]+[C] in Keyboard (Copy Command)

Select elements to modify the sections

6-4 Re-analyze/Re-design reflecting the Design Results

Code Checking Result Dialog >

Select (SEL) > 224(on), 1001(on), 1002(on), 2001(on)

(Refer to Figure below)

“Analysis / design results will be deleted. Continue?”

The right side of Select Identity-Element (Refer to ① of Figure above)

[Ctrl]+[V] in Keyboard (Paste Command)

Model > Elements > Change Element Parameters

Parameter Type > Section ID

Assign No. > 522

Analysis > Perform Analysis OR Re-analysis (Refer to Figure below)

Update Changed Properties Dialog

Dialog box after updating the selected sections

Modify sections using the Change Element Parameter

 Select Identity-Element

Select Type > Section

List > 224:SG4, 522:SG2, 1001:BR1, 1002:BR1, 2001:BR2

Design > Steel Code Check

(Refer to Figure below)

Select (SEL) > 224

(Refer to Figure below)

Confirm the results of the re-design

Stress ratio graph of 2∼4F SG1 (after modifying sections)

7. SRC Column Design

•  Applied Design Code : SSRC79

7-1 Create the Load Combinations

Unselect All

Results > Combinations > Load Combination

SRC Design tab

Option > Add (on)

Design Code > SSRC79

Scale Up Factor > 2.719, RX

Scale Up Factor > 2.504, RY

Select the SRC Design Code

7-2 Input the Design Parameters

Design > Design > SRC Design > Design Code

Design Code > SSRC79     

Tools > Setting > Unit System

Length > cm

Design > Design > SRC Design > Modify SRC Column Section Data

SEL > Section ID > 151 ~ 156

Reinforcing Main Bar > Auto Calculate Rebar Space (on)

Rebar > 12 - #8

Number of Rows > 4     

Modify SRC Column Section Data

7-3 SRC Code Check

Design > Design > SRC Design > SRC Code Check > Column Checking

SRC Code Checking Result Dialog