Revision of Ver.7.4.1

Beam Section Temperatures

Enter the temperature differences between specific locations of beam for thermal stress analysis.  The vertical temperature gradient is considered in concrete and steel superstructures with concrete decks, which are subject to temperature difference due to direct sun light and shade.

The temperature gradient analysis is applicable for elements with bending stiffness such as beam and plate elements. The gradient temperature produces the following equivalent moments:

Where,  is the linear thermal expansion coefficient, E is the modulus of elasticity, I is the moment of inertia about the relevant axis of the beam element,  is the temperature difference between the two extremities (outermost faces) of the element, h is the distance between the two extremities of the beam section, t is the thickness of the plate and  is the Poisson's Ratio.

A temperature difference may be also defined by the Temperature Gradient function. In case of Temperature Gradient, only the temperature difference between the top and bottom of a section can be entered. However, in case of Beam Section Temperature, temperature differences for certain locations in a section can be entered.

 

 

From the Main Menu select Load > Temperature Loads > Beam Section Temperature.

Select Static Loads > Temperature Loads > Beam Section Temperature in the Menu tab of the Tree Menu.

 

Load Case Name

Assign the load case name. Click to the right to enter additional load cases and modify or delete existing load cases.

 

Load Group Name

Select the desired Load Group Name. Click to the right to enter additional load group names and modify or delete existing load group names.

 

Options

Add: To enter new or additional partial temperature loads to beam elements

Replace: To replace previously entered temperature loads

Delete: To delete previously entered temperature loads

 

Direction

Local-y: Temperature difference in the direction of ECS y-axis

Local-z: Temperature difference in the direction of ECS z-axis

 

Revision of Ver.7.4.1

Ref. Position

Specify a reference location for temperature difference on a beam element.

Centroid: Centroid of beam element

+End (Top): The upper extreme fiber of the beam

-End (Bot.): The lower extreme fiber of the beam

 

Section Temperature

Initial Temperature
Specify the initial temperature in ?a href="..\..\04_Model\Structure_Type.htm">Structure Type?

Material
Define the material properties of the beam elements.

Element: Apply the material property information of the selected beam elements.

Input: Define the material properties to be applied to the thermal stress analysis.

Elast.: Modulus of elasticity

Therm.: Thermal expansion coefficient

Revision of Ver.7.4.1

B: Width being considered for temperature difference. If a section for which the temperature difference is to be considered is not a rectangle, the section needs to be transformed into an equivalent rectangular section.

H1, H2: Distances defining the locations of temperature differences from the reference position of the beam element

T1, T2: Temperatures at H1 and H2 respectively

Click to add the input data to the list. To modify the data, click after selecting and revising the relevant data. is similarly used.

Note
When a temperature load is applied linearly to structural elements, self-restrained stresses do not occur. However, if a nonlinear temperature load is applied to structural elements, self-restrained stresses may take place. Such internal retrained stresses occur without the presence of external restraints causing residual stresses internally.