Function
Produce the two-way shear (punching shear) check results at the supports of slab elements or at concentrated loads and the one-way shear check results along the user-defined Shear Check Lines.
Note
In order to use this function, Eurocode2:05 or ACI318-11,08,05 must be selected in Design > Concrete Design Parameter > Design Code.
Call
From the Main Menu select [Design] tab > [Type : Meshed Design] > [Perform/Result] group > [Slab Design] > [Slab Shear Checking]
Input
Load Combinations
Select a desired load case or load combination.
Click the ... Button to the right to enter new or modify existing load combinations. (Refer to "Static Load Cases / Combinations")
Punching Shear Check
Select for checking two-way shear.
Click the ... button to the right to select the format of displaying the stress distribution on a critical section either in the In Plane direction or the Normal direction.
Code : Check shear using the resulting member forces and loading data.
In this method, the program takes the axial force in the column supporting the slab as the shear force (Vu). The maximum shear force is calculated by summation of Vu and the fraction of unbalanced moment (γvMu). (Refer to the clause 13.5.3 of ACI318-11.)
The shear resistance of the slab (without shear reinforcement) at the basic control section is given by the smallest of following equations (equation 11-31 to 11-33 in ACI318-11).
If V_u < φV_c : section is safe in punching shear
If V_u > φV_c : provide shear reinforcement
Shear Reinforcement shall be permitted with slab thickness greater than 200mm (approximately 16times the shear rebar diameter, generally D13 or #4).
Where shear reinforcement perpendicular to axis of member is used,
FEM : Check shear using the resulting stresses obtained from the analysis.
Avg. by Element : Check by average element stress in case of a column.
Avg. by Side : Check by average edge stress in case of a column.
Force : Check shear using the resulting member forces and loading data.
Note. How to perform punching shear check 'by Force'
In this method, the program takes the axial force in the column supporting the slab as the shear force (V_Ed). The maximum shear force is calculated by multiplying V_Ed with shear enhancement factor β. The value of β is different for different columns. (as given in the code)
The shear resistance of the slab (without shear reinforcement) at the basic control section is given by
Where, the value of ρl is calculated by program as applied rebar ratio.
When the rebar data has not been assigned, V_Rd,c will be always .
If V_Ed < V_Rd,c : section is safe in punching shear
V_Ed > V_Rd,c : provide shear reinforcement
Stress : Check shear using the resulting stresses obtained from the analysis.
Avg. by Element : Check by average element stress in case of a column.
Avg. by Side : Check by average edge stress in case of a column.
Note Punching Shear Check by Stress
Two-way shear check by Force cannot reflect the shear stress due to unbalanced moments. The user must independently check shear for floor slabs or foundation mats where significant unbalanced moments are anticipated. Shear check by Stress can reflect the shear stress due to unbalanced moments.
1. Rectangular Column
1.1 Internal Column
- concrete strength = 270 kgf/cm2
- column section size = 40 cm * 90 cm
- slab thickness = 35 cm, rebar cover = 5 cm
① Calculate the design parameters
d = 35 - 5 = 30 cm
b0 = 2*70 + 2*120 = 380 cm
② Calculate the resulting shear stress
For the resulting shear stress at each location, use the average element stress or the average edge stress.
unit : kgf/cm2
| Position | Avg. by Element | Avg. by Side |
| AB | Max[ AB1,AB2,AB3,AB4 ] = 10.27 | Avg[ AB1,AB2,AB3,AB4 ]= 8.87 |
| BC | Max[ BC1,BC2,BC3,BC4,BC5,BC6 ] = 10.30 | Avg[ BC1,BC2,BC3,BC4,BC5,BC6 ] = 9.01 |
| CD | Max[ CD1,CD2,CD3,CD4 ]= 10.27 | Avg[ CD1,CD2,CD3,CD4 ]= 8.87 |
| DA | Max[ DA1,DA2,DA3,DA4,DA5,DA6 ] = 10.30 | Avg[ DA1,DA2,DA3,DA4,DA5,DA6 ] = 9.01 |
③ Calculate the design shear stress
④ Calculate the shear stress ratio
- Check by average element stress:
- Check by average edge stress:
1.2 Edge Column
- concrete strength = 270 kgf/cm2
- column section size = 40 cm * 90 cm
- slab thickness = 35 cm, rebar cover = 5 cm
① Calculate the design parameters
d = 35 - 5 = 30 cm
b0 = 2*110 + 70 = 290 cm
② Calculate the resulting shear stress
For the resulting shear stress at each location, use the average element stress or the average edge stress.
Unit: kgf/cm2
| Position | Avg. by Element | Avg. by Side |
| AB | Max[ AB1,AB2,AB3,AB4 ] = 11.27 | Avg[ AB1,AB2,AB3,AB4 ]= 9.87 |
| BC | Max[ BC1,BC2,BC3,BC4,BC5,BC6 ] = 11.30 | Avg[ BC1,BC2,BC3,BC4,BC5,BC6 ] = 10.01 |
| CD | - | - |
| DA | Max[ DA1,DA2,DA3,DA4,DA5,DA6 ] = 11.30 | Avg[ DA1,DA2,DA3,DA4,DA5,DA6 ] = 10.01 |
③ Calculate the design shear stress
④ Calculate the shear stress ratio
- Average shear stress by element :
- Average shear stress by side :
1.3 Corner Column
- concrete strength = 270 kgf/cm2
- column section size = 40 cm * 90 cm
- slab thickness = 35 cm, rebar cover = 5 cm
① Calculate the design parameters
d = 35 - 5 = 30 cm
b0 = 110 + 70 = 180 cm
② Calculate the resulting shear stress
For the resulting shear stress at each location, use the average element stress or the average edge stress.
Unit: kgf/cm2
| Position | Avg. by Element | Avg. by Side |
| AB | Max[ AB1,AB2,AB3,AB4 ] = 13.27 | Avg[ AB1,AB2,AB3,AB4 ] = 12.87 |
| BC | Max[ BC1,BC2,BC3,BC4,BC5,BC6 ] = 13.30 | Avg[ BC1,BC2,BC3,BC4,BC5,BC6 ] = 13.01 |
| CD |
- |
- |
| DA | - | - |
③ Calculate the design shear stress
④ Calculate the shear stress ratio
- Average shear stress by element :
- Average shear stress by side :
2. Circular Column
2.1 Internal Column
- concrete strength = 270 kgf/cm2
- Diameter of the column = 70 cm
- slab thickness = 35 cm, rebar cover = 5 cm
① Calculate the design parameters
d = 35 - 5 = 30 cm
b0 = SUM[ Length of S1 ~ S16 ] = *100 = 314.16 cm
② Calculate the resulting shear stress
For the resulting shear stress, use the average element stress.
Max[ Stress of S1 ~ S16 ] = (11.85 + 10.77) / 2 = 11.31 kgf/cm2
③ Calculate the design shear stress
④ Calculate the shear stress ratio
- Check by average element stress:
2.2 Edge Column
- concrete strength = 270 kgf/cm2
- Diameter of the column = 70 cm
- slab thickness = 35 cm, rebar cover = 5 cm
① Calculate the design parameters
d = 35 - 5 = 30 cm
b0 = SUM[ Length of S1 ~ S12 ] = *100*(1 - 2*45/360) = 249.81 cm
② Calculate the resulting shear stress
For the resulting shear stress, use the average element stress.
Max[ Stress of S1 ~ S12 ] = (12.85 + 11.77) / 2 = 12.31 kgf/cm2
③ Calculate the design shear stress
④ Calculate the shear stress ratio
- Check by average element stress:
2.3 Corner Column
- concrete strength = 270 kgf/cm2
- Diameter of the column = 70 cm
- slab thickness = 35 cm, rebar cover = 5 cm
① Calculate the design parameters
d = 35 - 5 = 30 cm
b0 = SUM[ Length of S1 ~ S8 ] = *100*(1 - 4*45/360) = 157.08 cm
② Calculate the resulting shear stress
For the resulting shear stress, use the average element stress.
Max[ Stress of S1 ~ S8 ] = (13.85 + 12.77) / 2 = 13.31 kgf/cm2
③ Calculate the design shear stress
④ Calculate the shear stress ratio
- Check by average element stress:
Type of Display
Contour
Display the displacement of the model in contour.
The ... Button
Ranges: Define the contour ranges.
The Customize Range... Button : Assign the color distribution range of contour. Using the function, specific colors for specific ranges can be assigned.
Note
Contour Range Max/Min values can be larger than the max/min output values. If the Contour Range values exceed the output values, they are entered at Rank 0 and Rank 11.
Number of Colors : Assign the number of colors to be included in the contour (select among 6, 12, 18, 24 colors)
Colors : Assign or control the colors of the displacement contour.
Color Table : Assign the type of Colors.
The Customize Color Table Button : Control the colors by zones in the contour.
Reverse Contour : Check on to reverse the sequence of color variation in the contour.
Contour Line : Assign the boundary line color of the contour
Element Edge : Assign the color of element edges while displaying the contour
Contour Options : Specify options for contour representation
Contour Fill
Gradient Fill : Display color gradient (shading) in the contour.
Draw Contour Lines : Display color boundaries in the contour.
Draw Contour Line Only : Display only the colored boundaries of the contour.
Mono line : Display the boundaries of the contour in a mono color.
Contour Annotation : Legend or annotation signifying the ranges of the contour is displayed.
Spacing : Display the spacing for the legnd or annotation.
Coarse Contour (faster) (for large plate or solid model) : Represent a simplified contour for a large model using plate or solid elements in order to reduce the time required to represent a complete contour.
Extrude : Where plate elements or solid elements along a cutting plane are represented in contour, a three dimensional contour is created. The positive direction of the analysis results is oriented in the z-axis direction of the local element coordinate system.
The option is not concurrently applicable with the Deformed Shape option. Similarly, the option cannot be concurrently applied to the cases where the Hidden option is used to display plate element thicknesses or the Both option is used to represent Top & Bottom member forces (stresses).
Values
Display the nodal displacements in numerical values.
The font and color of the numbers can be controlled in Display Option.
The ... Button
Decimal Points : Assign decimal points for the displayed numbers
Exp. : Express as exponential
Min & Max : Display the maximum and minimum values
Abs Max : Display the absolute maximum value
Max : Display only the maximum value
Min : Display only the minimum value
Limit Scale(%) : Set the screen display limit for nodal displacements relative to the selected maximum or minimum value
Set Orientation : Display orientation of numerical values
Note
The default Decimal Points can be controlled in "Preferences".
Set Orientation = 0 horizontally displays the numerical values to the right of nodes or elements.
The orientation angle represents the counter-clockwise direction, which may be used to enhance the readability of the numbers.
Legend
Display various references related to analysis results to the right or left of the working window.
The ... Button
Legend Position : Position of the legend in the display window
Rank Value Type : Specify a type of values in the Legend and the number of decimal points.
One-Way Flexural Design
Display one-way shear check results along the user-defined shear check lines.
Click the ... Button to prompt the dialog box, and then enter the locations for checking one-way shear.
Defined Shear Check Lines : List of defined cutting lines
The Add Button : Add the information contained in the Cutting Line Detail to the list of Defined Cutting Lines
The Delete Button : Delete a defined cutting line
The Modify Button : Modify a defined cutting line
Cutting Line Detail : Define a Cutting Line.
Name : Name of a Cutting Line
Pnt1 : Start point of a Cutting Line
Pnt2 : End point of the Cutting Line
Options
Define the plane and color for representing the graph.
Normal : Display the graph in the Normal direction of floor slab elements.
In Plane : Display the graph in the In-Plane direction of floor slab elements.
Scale Factor : Scale factor for diagram output
Reverse : Express the Diagram in the reverse direction.
Graph
Produce the output in a Graph Window ( valid only if 'Cutting lines' is selected).
Access the Plate Cutting Diagram Mode Dialog Box to determine the type of Graph Window.
The ... Button
Draw graphs on separate panes : Graphs pertaining to different Cutting Lines/Planes produced separately
Draw graphs on All in one pane : All the graphs pertaining to different Cutting Lines/Planes simultaneously produced in one graph
X-axis : Define the X-axis of the graph
Distance from Pnt1 : Distance from the first point
Global X coord.
Global Y coord.
Global Z coord.
Value Output : Produce the moments in numerical values on the Cutting Line Diagram(s).
MinMax Only : Produce only the maximum and minimum values on the Cutting Line Diagram(s).
Element Edge
Specify the direction to produce the one-way shear check results of the slab elements with reference to the user-defined Cutting Line.
Both : Produce the Max/Min one-way shear check results of the slab elements on both sides of the user-defined Cutting Line.
Left : Produce the one-way shear check results of the slab elements on the left side of the user-defined Cutting Line.
Right : Produce the one-way shear check results of the slab elements on the right side of the user-defined Cutting Line.
Note
When the user-defined Cutting Line does not pass through the Mesh Line, Both, Left and Right will produce the same one-way shear check results.
Operations
The Design Result Button : Produce the flexural checking results of wall elements in a text format.