Shear Reinforcement

In the Shear Reinforcement tab, you can define the stirrup reinforcement to be used for the shear design of the member.

Defining Shear Reinforcement

Fields

This section provides the option to define ranges for the stirrup reinforcement. Only one entry is preset here, representing a kind of "basic reinforcement". You can adjust this default and divide the one large 'field' into segments (see image Define shear reinforcement). Use the button at the end of the list to create new fields.

For the graphical representation of the stirrup reinforcement, it may be necessary to specify an 'offset' for the edge distances of stirrups.

Parameters

In this section, you can specify the properties of the shear reinforcement. The parameters always refer to the field selected in the 'Fields' list on the left.

Basic Data

Select the 'Stirrup type' from the list. Various stirrup shapes are available.

Selecting Stirrup Type

Assign a Material to the stirrup reinforcement. If you have already defined the suitable reinforcing steel in the model, it is available for selection in the list. Otherwise, you can create a new material via the button in the input field by accessing the material library in the New Material dialog.

Stirrup Parameters

Define the 'Rebar diameter' d_s,st of the stirrups, the 'Distance' s_s,st between the stirrups, or the 'Number' n_s,st of stirrups in the field. Usually, you specify the diameter of the stirrups d_s,st and the distance s_s,st. The stirrup number is determined automatically from this. However, you can also specify the number of stirrups n_s,st. The program then determines the appropriate distance for the field. You can read the reinforcement area of the existing stirrup reinforcement in the category below.

Defining Stirrup Parameters

If the program is to design the diameter or the number during the design, select the Auto option.

Automatic Determination of Rebar Diameter

If the Rebar diameter has to be determined, you can specify the smallest and largest possible diameter for the design. A user-defined list of possible diameters allows you to restrict the stirrup reinforcement to specific bar diameters.

If the program has to determine the Distance, define the minimum and maximum permissible stirrup spacing as well as the increment Δ_x for the design process.

Automatic Spacing Determination in Reinforcement Models

Reinforcement Areas

The reinforcement cross-section resulting from the parameters of the 'Stirrup Reinforcement' section is displayed here. Alternatively, you can specify the reinforcement area a_sw directly in [cm²/m] or [in²/ft]. From this, the program determines the required distance s_s,st and the resulting number n_s,st of stirrups. The diameter d_s,st remains unchanged.

Position of Field

In this category, you specify where the 'Field' with the stirrup reinforcement is arranged in the member. You can define this position with a 'Reference' to the start, the end, or an x-location. Select the appropriate option in the list to define the reference point for the position of the field.

Defining Span Position via x-Location ("Relative" Definition Format)

Furthermore, you can control with the 'Definition format' whether the distances are to be defined absolutely in length units or relatively in percentages.

Enter the 'Start' x₁ and the 'End' x₂ of the field. The 'Span' l_s of the field thus represents the length of the stirrup segment in the member.

Edge Distances of Stirrups

The 'Arrangement rule' controls how the stirrups are positioned at the edges of the field. Several variants are available for selection.

Selecting Layout Rule for Border Distances of Stirrups

With the default 'Start equals End', the program determines a residual length from the number n_s,st and the distance s_s,st of the stirrups, which is applied in equal parts at the start and at the end of the field. The input fields for Δ_i and Δ_j are locked.

With the other options, you can define the edge distances of the stirrups manually:

• 'Start defined': Enter the start offset Δ_i, which defines the position of the first stirrup in the field. The distance Δ_j at the end of the field is determined automatically; this value is not editable.
• 'Start = Residual length to stirrup spacing': This option is not possible for the first field, but only for following fields. With this rule, the distances Δ_i and Δ_j are determined automatically; the values are not editable. If you delete the previous field, the option is automatically changed to 'Start defined' and the previously determined value is entered as the start offset Δ_i.
• 'End defined': Enter the end offset Δ_j, which defines the position of the last stirrup in the field. The distance Δ_i at the start of the field is determined automatically; this value is not editable.
• 'End = Residual length to stirrup spacing': The program does not apply a start offset. From the distance s_s,st of the stirrups, the possible number of stirrups n_s,st is determined and the residual length at the end of the field is defined.

Information

Finally, you can find the following information about the stirrup reinforcement of the current field:

• Length of one stirrup L_st,1
• Length of all stirrups L_st as sum
• Weight of one stirrup W_st,1
• Weight of all stirrups W_st as sum

Graphic

In the two graphic areas of the tab, the reinforcement is displayed graphically: On the right, you see the cross-section of the member, at the bottom the longitudinal section. Your entries are implemented dynamically there, offering a good control option.

Reinforcement Graphics for Section and Member

Cross-section

The graphic on the right shows the cross-section of the member with the defined stirrup and longitudinal reinforcement. The concrete cover is considered for the reinforcement arrangement. The local axes z and y of the member are also displayed in the cross-section graphic.

The cross-section graphic refers to the reinforcement at the 'Location x' along the member, which is specified in the field below the graphic. With the default setting x = 0.000 m, the reinforcement at the member start is displayed. To display the reinforcement at another member location, enter the corresponding distance. The location x is then marked with an arrow in the longitudinal section.

The buttons below the graphic have the following functions:

	Switches between cross-section graphic and model view
	Displays only the longitudinal reinforcement selected in the Positions list
	Shows or hides the member axes
	Shows or hides the dimensioning of the cross-section
	Allows printing the graphic in various variants

Longitudinal Section

The graphic in the lower area of the dialog shows the longitudinal section of the member with the defined stirrup and longitudinal reinforcement, as well as the support symbols from the defined effective lengths and design supports.

For working in this graphic area, you can use all mouse functions described in the chapter Graphic Control of the RFEM manual. This allows the reinforcement of the member to be displayed zoomed or spatially.

Displaying Reinforcement in Longitudinal Section Zoomed in 3D View

The buttons next to the graphic have the following functions:

	Allows setting the view in various variants
	Allows the display in different member axis directions
	Allows representation as wireframe, solid, or transparent model
	Allows showing and hiding various auxiliary and model objects
	Displays the member symbolically horizontally or in real position
	Allows printing the graphic in various variants
	Opens the Reinforcement Arrangement window
	Displays the overall view of the member