Deep Beam Design – Using Dxf

Deep Beam Design – Using Dxf

Deep Beam – Design Specification

http://astruttie.aroad.co.kr/help/Tutorial1/AStrutTie-Tutorial-DeepBeam.html

Let’s look at how to input and use the AStrutTie program through the design of deep beam using strut-tie model.

Thickness : 0.800m

fck : 24MPa

fy : 300MPa

Unit : kN.m

Code : ACI 318-14


Import Dxf

– Click [New]

 Set  ACI 318-14

Load the dxf file you created.

The layer names corresponding to the structures are OUT, IN

The layer name corresponding to truss modeling TRUSS

Only Line accepted

Sample dxf file :  http://astruttie.aroad.co.kr/wp-content/uploads/2017/05/DeepBeam-1-dxf.zip

– Click [Import] The function is activated only in Professional Version.

Import DeepBeam-1.dxf (Unzip the DeepBeam-1-dxf.zip)


Load Define and Loading

1. Load Define

– [Defind – Static Load]

Load Name : Dead,   Description : Description

Click [OK]

2. Loading

– Select two of the top of the absence by dragging

Click [Assign – Static Load]

Right-click on the left side of the load starting point

After clicking Static Load, the Element Static Loads (Dialog) appears by clicking the right button of mouse

when the color of node changes from green to red. And then, loads are assigned by clicking Add button.

Click [Add]

Choose [Relative]

1  Distance:0.0, Load:-1000

2  Distance:1.0, Load:-1000

3, 4 Distance:0, Load:0

[OK]

– Click [Defind – Load Combinations]

Click [Add]

LC01 : Dead=1.0, LC02 : Dead=1.3

Click on the load in the Work Tree and check it on the screen.

[save] – DeepBeam-1.stm


Make Area

– Select all members created by dragging

Design – [Create Area] click

– Click [Defind – Area Properties]

Thickness=0.800m

Compressive Strength of Concrete (fck)=24MPa,

Elastic Modulus of Conctete (Ec)=27,849MPa

– Click [Defind – General Properties]-Steel Tab

Yield Strength (fy)=300MPa,

Elastic Modulus (Es)=200,000MPa


Modeling Mode

– Modeling Mode change

Click [Beginning Mode] → Modeling Mode


ESO

– Select [ESO]  The function is activated only in Professional Version.

On Work tree, Load Combination : LC01 select to see load and modeling

Select [LC02]

On Work tree, Load Combination : LC02 select to see load and modeling

– Click [Project Information]

Mesh size for ESO (m) : 0.1

– Click [View Options]

Node –  On

Node name – Off

Select 5 nodes on the bottom left

Click [Assign Restraints]

Set roller

Select 5 nodes on the bottom right

Click [Assign Restraints]

Set roller

Select the leftmost joint of the lower part

Click [Assign Restraints]

Set hinge

– Click [View Options]

Node –  Off

– Click [Analysis, Print Options]

Elimination Ratio for ESO : 0.01 → [OK]

– Choose LoadCase : LC01   – 1

Click [Run Model Analysis] – 2

View ESO analysis result   – 3


Stress Flow

Tip : The work flow is almost the same as ESO, please refer to ESO.

– Select [Stress Flow]

On Work tree, Load Combination : LC01 select to see load and modeling

Select [LC02]

On Work tree, Load Combination : LC02 select to see load and modeling

– Project Information – Mesh size for Stress Flow (m) : 0.2

VIEW – View Options Click

Node –  On

Node name – Off

Select 3 nodes on the bottom left

[Assign Restraints]

Set roller

Select 3 nodes on the bottom right

[Assign Restraints]

Set roller

Select the leftmost joint of the lower part

[Assign Restraints]

Set hinge

– [Run Model Analysis]


Truss

– Select [Truss]


Load Assign

– View Option- Boundary Load : True

– Select two of the top of the absence by dragging

 Click [Boundary Load to Truss Load]


Set Restraint and Edit Truss

– Select the leftmost joint of the lower part

[Assign Restraints]

Set hinge

Select the rightmost joint of the lower part

[Assign Restraints]

Set roller

– Delete – Unnecessary element

– Truss Modeling is complete.


Define Tie Types

– Truss members are all created and proceed to tie and strut member settings.

Click [Define Reinforcement Ties]

– Click [Add]

Rebar Name = Upper

Rebar Type = Main Rebar

Main Rebar Type = Top Main Rebar

Centroid of Rebar (mm) = 100.0

1st Cycle Rebar Diameter = #8

No. of 1st Cycle Number = 8

Click [Add]

Rebar Name = Lower

Rebar Type = Main Rebar

Main Rebar Type = Bottom Main Rebar

Centroid of Rebar (mm) = 100.0

1st Cycle Rebar Diameter = #8

No. of 1st Cycle Number = 8

Click [Add]

Rebar Name = Shear

Rebar Type = Shear Rebar

Shear Type = Vertical Shear

Diameter = #10

Number of Legs = 2

Rebar C.T.C (mm) =300


Assign Tie Types

– Select upper element

Click [Assign Tie Type]

Choose [Upper] → O.K

– Select bottom element

Click [Assign Tie Types]

Choose [Lower] → O.K

– Select center element

Click [Assign Tie Types]

Choose [Shear] → O.K


Bearing Plate

– Select load acting node

Click [Assign Bearing Plates]

Vertical plates

B = 400mm

L = 350mm

T = 50mm

Effective Width = 400mm

[OK]


Max. Width and Outer Element

– Click [View Options]

Max. Strut/Tie Width –  On

Click [Calculate Max. Width ]

The available widths of all elements in a strut-tie model, calculated automatically by the program,

are displayed by executing the function DESIGN-Element Information or ASSIGN-Outer Element.

The available widths can be modified.

– Technical Reference

The protrusion at the top is the max width considering the bearing plate.
If you want to change the max width of a member, you can change it by two methods.

The first is assign of Outer Element, the second is edit of Element Information.

Reducing the maximum width with this function will result in a more secure design, but overshooting can be over-designed.

– Technical Reference – example

Select Element 5

Click [Outer Element]

I : 247.3

Click [OK ]

Double Click [No. of Element]

Element 7,  I-Width : 0.353

Element 8,  I-Width : 0.353

Element 9,  I-Width : 0.247

Click [Close ]


Assign Strut Types

– Select all element

Click [Assign Strut Types]

Choose [Prismatic Strut] → O.K

– Technical Reference

In this example, all struts are set to Prismatic, but you can apply them differently at the designer’s discretion.

An indeterminate truss will show different results depending on the selected strut type.


Truss Analysis and Design Review

1. Truss Analysis

– Click [Renumbering]

– Click [Run Analysis]

2. Design Review

– Click [Design Review]

Need to increase the amount of lower rebar.

Click [Define Reinforcement Ties]

Lower 1st Cycle Diameter : #9 →[OK]

Click [Design review]

Main Rebar Tie is OK.


Report Preview and Save Report

– Move to [Report] tap

Double Click [Report Preview]

Check off : LC02:1.30D → [Preview]

– rtf, xlsx output are proceed in the same way.

http://astruttie.aroad.co.kr/help/Tutorial1/AStrutTie-Tutorial-DeepBeam.html