## Function

- Enter the sectional properties for the following structural elements: Truss, Tension-only, Compression-only, Cable, Gap, Hook, and Beam Element.
- In the PSC tab, you can input the sectional property data for prestressed concrete members.
- The available PSC Box section shapes can be broadly categorized into PSC-1Cell/2Cell, 3Cell, nCell, Mid, I, Half, Tee, and Plat, allowing for the definition of various section shapes.

## Call

From the main menu, select **[Properties] tab > [Section Properties] group > [Section Properties]**** > [PSC]**

## Input

Fig. Section(PSC) dialog box

### Joint On/Off

Check on the joint numbers to activate the entry fields to additionally define the variant dimensions of the section.

**JO1, JO2, JO3**: Selectively check on the points in the Outer tab referring to the guide diagram.

**JI1, JI2, ..., JI5** : Selectively check on the points in the Inner tab referring to the guide diagram.

### Section Type

Assign the number of internal compartments in the section. (1 Cell: single cell, 2 Cell: double cell)

### Shear Check

Check shear stresses at Z1, Z2, and Z3 locations. Z1 and Z3 can be either input directly by the user or specified automatically. If the Auto option is checked, the program checks shear at the top and bottom ends of the web.

**Z1**: Distance from the centroid to the underside of the top flange at the webs

**Z3**: Distance from the centroid to the upper side of the bottom flange at the webs

If the "AUTO" option is selected, the program automatically checks the shear at the following locations based on the PSC section shapes.

**Locations for checking the shear resistance**

### Web Thick

Shear forces are calculated at the parts critical to shear in the PSC section. The user can directly enter the position. If the Auto option is checked on, the program checks shear at the top and bottom ends of the webs (Z1 and Z3 in the PSC Viewer dialog).

**for Shear(total)** : To calculate the shear stress, enter the minimum thickness of the web in the desired location. Enter the web thickness in the y-axis direction of the element coordinate system to ensure a valid section for shear.

**t1** : Sum of web thicknesses at Z1 for shear stress check

**t2** : Sum of web thicknesses at Z2 for shear stress check

**t3** : Sum of web thicknesses at Z3 for shear stress check

**for Torsion(min.)** : To calculate the torsional stress, enter the minimum thickness of the flange required for a valid section for torsion. Enter the minimum distance for the flange thickness to ensure a valid section for torsion. If there are three or more webs, enter the thickness of the outermost flange.

**t** : The web thickness (tT) for shear checks related to torsional moments.

**Mesh Size for Sitff. Calc.** : Enter the mesh size for the stiffness calculation of PSC sections. A finer mesh will provide more accurate results, but it may significantly increase the calculation time for section properties. Enter an appropriate size, ensuring that the maximum size is smaller than the minimum thickness of the section.

### Outer

Outer dimensions

**HO1, HO2, ...** : Enter the dimensions referring to the guide diagram on the left side of the dialog box.

### Inner

Inner dimensions

**HI1, HI2, ...** : Enter the dimensions referring to the guide diagram on the left side of the dialog box.

### Table Input

Input PSC section data in a table. It is convenient to input the data in a spreadsheet format since there are many items to input. Section data that is frequently used can be saved as an Excel data for later use.

Click **Display Centroid** to display the centroid of the section.

### PSC Viewer

Display the section to a true scale based on the dimensions and the section shape.

### PSC Section Type

Various types of PSC (Prestressed Concrete) section shapes can be inputted.

**PSC-1CELL, 2CELL**

: Common 1-cell and 2-cell PSC Box cross-section shapes

**PSC-3CELL**

: 3 Cell PSC Box cross-section

A data table calculated based on the key dimensions of the section is displayed.

**Default**: Enter the basic dimensions of the 3-cell PSC Box.

**Option**: Enter the dimension of the joints which is checked at the Joint On/Off.

**PSC-nCELL**

: nCell PSC Box cross-section

**Type** : Assign the type of the web of a PSC Box Section (Refer to PSC Viewer)

**Size** : Enter the size of a PSC Box Section.

**PSC-nCELL2**

: nCell2 PSC BOX cross-section

**Num. of Cell** : Number of Cells

**Symmetry**: Select whether the section is symmetrical or not. Unchecking this option will activate the Right entry field.

**Cell Type** : Select the shape of cell

**Polygon**

**Circle**

**Side Hole** : Select whether to include a circular hole or not.

**Left Side**: The shape of left-side PSC Section

**Right Side** : The shape of right-side PSC Section (activated if unsymmetrical)

**PSC-MID**

: Mid PSC beam cross-section

**Symmetry** : Select whether the section is symmetrical or not. Unchecking this option will activate the Right entry field.

**Cell Type**

**Left** : Select the desired section shape among the None, Circle and Polygon.

To calculate Ixx of a PSC section, use the least value of flange thickness considering the haunch.

For the sloped upper flange,

Here, Am, ts and ds represent the closed sectional area, the least thickness and the section length respectively.

t1~t6 are the least thickness, and the upper flange thickness (ta and t5) will be determined by the least thickness among ta~td.

d1~d6 represent the length of each side. Am represents the closed area, bounded by the lines that run parallel to the outer lines of the section and pass through the center points of the least thicknesses.

**PSC-I**

: I type PSC beam cross-section

**Symmetry** : Select whether the section is symmetric or not. Unchecking this option will activate the Right entry field.

**Section Name** : The user can manually specify the section dimensions by selecting "None" or select one of the sections in the built-in database for the AASHTO and several DOT standard sections. Those DOTs are: Caltrans, Iowa DOT, Missouri DOT, Ohio DOT, Texas DOT, Virginia DOT, and Wisconsin DOT.

When AASHTO or one of the DOT is selected, the corresponding standard sections are listed as shown below:

**PSC-HALF**

: PSC box half cross-section

**Cell Type**

**Symmetry** : Select the symmetry option. If "Off" is chosen, the input field for "Right" will be enabled.

**Left** : Select the desired section shape among the None, Circle and Polygon.

Grillage model is used for constructing a multi-cell box girder.

**Outer** : Outer dimensions

**HO1, HO2, ...** : Enter the dimensions referring to the guide diagram on the left side of the dialog box.

**Inner** : Inner dimensions

**HI1, HI2, ...** : Enter the dimensions referring to the guide diagram on the left side of the dialog box.

When a multi-cell PSC Box is modeled using a grid model, it will be easier to use PSC-Half for the exterior section and PSC-Mid for the interior section.

**PSC-TEE**

: T type PSC beam cross-section

**PSC-PLAT**

: Cross-section with a circular or polygonal hole inside

**Section Type** : Choose among Half, 1Cell and 2Cell.

**Half** : You can choose between Left and Right.

**1 Cell** : You can choose between Circle and Polygon.

**2 Cell** : You can input a two-cell cross-section with circular voids.

**PSC-Value**

: Arbitrary PSC cross-section

**Define by Coordinates...** : You can enter a PSC (Prestressed Concrete) cross-section using coordinate input.

**Input Method**

**X, Y** : Define the Polygon by inputting the absolute coordinates.

**DX, DY** : Enter the increment from the point on the Polygon to define the coordinates.

**Add** : Complete the Polygon with the coordinates inputted.

**Delete** : Delete the polygon selected from the list.

**Import** : Import the predefined section data (*.uds).

**Export** : Export the define section data to a file (*.uds)

**Section Data**

**DB** : PSC Section Data Base for the United Kingdom and Italy are provided.

The standard sections of several DOTs are implemented in the PSC database under USA option.

Those DOTs are Iowa DOT (IADOT), Illinois DOT (ILDOT), Massachusetts DOT (massDOT), Louisiana DOT (LADOT), Ohio DOT (ODOT), Rhode Island DOT (RIDOT), Texas DOT (TXDOT), and Wisconsin DOT (WIDOT).

For each DOT type selected, the corresponding sections are listed under the 'Select DB' box.

**Import from SPC...** : Click the button to import the *.sec file. Once the section data is loaded, the calculated section properties and shape from SPC will be inputted.

**Param. for Design** : Enter the section dimensions to be used for design, referring to PSC Viewer. The dimensions are used for calculating the shear strength. If 0 is inputted in T2, then the program automatically recognizes the section as a Tee section, and uses BT as web thickness. The parameters for closed section and open section are calculated using the following equations:

**The method of entering design dimensions depends on the section type**

**1. Box shape (Closed section)**

Refer to PSC Viewer

**2. T shape (Open section)**

For the design of a T-section, specify 0 for T2.

Web thickness is specified by 'Thk. for Torsion(min.)', and flange width is specified by the distance between y1 and y2 of Section Properties. That is, BT does not affect

**3. I shape (Open section)**

or design of I-section, specify 0 for BT

Thicknesses of the top and bottom flanges are specified by T1 and T2 respectively. Web thickness is specified by Thk. for Torsion(min.).

Widths of the top and bottom flanges are specified by the distance from y1 to y2 and from y3 to y4 respectively.

Closed section :

Open section :

Here, F represents the enclosed area by the closed section of the plate, and t represents the plate thickness.

When applying Chinese design standards, Roark's Formula is used, and the calculation equation is as follows:

**Thk. for Torsion(min.)** : To calculate shear stress, enter the minimum thickness of the flange required for torsion. Input the shortest distance for the flange thickness to ensure an effective section against torsion.

**Shear Check** : To calculate the shear force in vulnerable sections of the PSC section, select "Shear Check" and enter the values for Z1 and Z3. The value for Qy and the flange thickness for shear check can be entered manually by the user or calculated automatically by checking the "Auto" option.

This section cannot be defined as a Tapered Section Group, and it cannot be used in the Composite Section for Construction Stage.

Refer to "Calculation of arbitrary section form using SPC" for a detailed explanation.

**PSC Section with corrugated steel web**

**Symmetric**

**Haunch** : Section with haunch

**CMP** : Enter the dimensions for corrugated steel web, referring to the guide diagram.

**E.F.D.** : End Fixity degree ( ). Factor to calculate design buckling stiffness.

**L.R.F.** : Length Reduction Factor ( ). Factor to calculate design buckling stiffness.

**Calc.**

**Material**

**Select Material From DB...**

**Es/Ec** : Enter ratio of elastic modulus of steel to concrete.

**Ds/Dc** : Enter ratio of density of steel to concrete.

**Ps** : Enter Poisson's Ratio of steel.

**Pc** : Enter Poisson's Ratio of concrete.

The maximum number of voids that can be created is 21.

**PSC-CMPWEB**

: PSC section with corrugated plate web

**Symmetric** : Check the box for symmetric section.

**Hunch** : Check the box for including a haunch in the section.

**CMP** : Enter the dimensions of the corrugated plate for the haunch (refer to the provided diagram).

**E.F.D.** : Coefficient for calculating the restraint factor (β) and design buckling strength.

**L.R.F.** : Coefficient for calculating the shrinkage strain (η) and design buckling strength.

**Material** : Enter material data for the section.

**Select Material from DB...** : Load material data from the database.

**Es/Ec** : Enter the ratio of elastic modulus between steel and concrete.

**Ds/Dc** : Enter the ratio of weight between steel and concrete.

**Ps** : Enter the Poisson's ratio of steel.

**Pc** : Enter the Poisson's ratio of concrete.

The maximum number of voids that can be created is 21.

### Outer

Enter the dimensions of the outer section.

**HO1, HO2, ...** : Refer to the dimension input guide on the left side of the dialog box and enter the dimensions accordingly.

### Inner

Enter the dimensions for the inner section.

**HI1, HI2, ...**: Cross section on the left side of the dialog box

### Table Input

Click the button to enter PSC section data in table format. For PSC sections, it is convenient to enter the data in a spreadsheet format as there are many input fields. For frequently used sections, you can save the data in an Excel file and copy it for input.

Enter the PSC section data using a table

### Consider Warping Effect(7th DOF)

You have the option to consider the torsional effects. When there is an uneven torsion resulting from the restricted torsional displacement, torque is resisted by St. Venant's torsional shear stress and warping torsion. In cases involving curved members, eccentric loads, or differences between the center of gravity and the shear center, simulating the warping torsion effect using a 1D beam element can provide more accurate results.

When considering the warping effect (7 degrees of freedom), the warping coefficient (Iw), warping functions (w1, w2, w3, w4), and shear deformations due to the twisting moment can be checked in the sectional properties dialog box.

Applicable element types : General beam/Tapered beam

Applicable boundary condition types : Supports, Beam End Release

Applicable analysis types : Linear Static, Eigenvalue, Buckling, Response Spectrum, Construction Stage Analysis, Moving Load Analysis

Post-processing results : Reviewable in reaction forces, displacements, member forces, and stresses.