Intro
This plugin calculates the thermal actions on bridge structures based on Temperature Effects from Section 3.5 of the STRUCTURES DESIGN MANUAL for Highways and Railways 2013 Edition (SDM 2013). It takes into account both uniform temperature changes and temperature gradients within the superstructure to determine the resulting thermal forces.
Version
- v1.0.0 : Plugin release
Applicable Standards
- General Use
Benefits of this plugin
Quickly and accurately analyze the thermal effects on the bridge structure due to temperature variations.
- Accurately models thermal actions based on SDM 2013, considering both uniform temperature changes and temperature differences.
- Supports quick integration of thermal actions into the structural analysis for effective design.
- Visualizes the impact of thermal effects on the bridge structure, including thermal gradients and uniform temperature variations.
- Ensures that all thermal contributions are accurately represented in the final design.
How to use this plugin?
[Uniform Temperature]
1. Input parameters based on structure type : Launch the plugin and allows the user to input parameters related to the structure for accurate thermal action calculations.
- Superstructure Type : Refer to Figure 3.2 for classification as per SDM2013
- Structure Type : Normal or Minor structures, refer to Clause 3.5.2 (3)
- Deck Surfacing Type : Refer to Table 3.18 for classification as per SDM2013, when selecting "Thickness", it can define deck surfacing thickness.
- Height above Sea Level : Refer to Clause 3.5.2 (5) as per SDM2013
2. Select UNIFORM tab for assigning uniform temperature
3. The Adjustment to Temperature differs between two calculation methods:
-
- Ceiling Method: Uses negative adjustment values, which significantly affect the calculations.
- Linear Interpolation: Determines how intermediate adjustments are applied, leading to different final results compared to the Ceiling Method.
4. Thermal Action parameters and calculation results based on user inputs. Displays calculated thermal action parameters such as uniform bridge temperature and adjustments. These values are provided for reference purposes only.
5.Load Cases Assignment for expansion and contraction due to uniform temperature. select target elements and allow the assignment of specific load cases for thermal expansion and contraction.
6. Apply Uniform Temperature Loads. Executes the loading process for uniform temperature effects on selected elements.
[Successful Application: the uniform temperature loads]
[Temperature Differences]
1. Input parameters based on structure type : Refer to the Uniform Temperature section for detailed instructions on inputting parameters related to the structure type.
2. Select DIFFERENCES tab for assigning temperature differences:
3. The Adjustment to Temperature differs between two calculation methods: Also refer to uniform temperature section.
4. Thermal Action parameters and calculation results based on user inputs. Displays calculated thermal action parameters, such as temperature differences across bridge components and adjustments. These values are provided for reference purposes only.
5. Load Cases Assignment for heating and cooling due to temperature differences:
Select target elements and assign specific load cases for thermal heating and cooling effects, based on the calculated temperature differences.
6. Apply Temperature Differences Loads: Execute the loading process for temperature differences on the selected elements, applying calculated differential temperature effects for structural analysis.
[Successful Application: the temperature difference loads]
Note
Plugin's Limitations and Considerations
The following are some limitations and considerations when applying the load.
Common Limitations
1) Identical Load Cases: Each load case must be identical for uniformity.
2) Load cases must be pre-defined in the Load Case Menu before application.
3) Loads are applied as a relative temperature value to the initial temperature specified in MIDAS Civil.
Uniform Bridge Temperature
1) Element Types: Can be applied to all element types.
2) Element Temperature Load (from MIDAS Civil) must not be assigned in the selected load case.
Temperature Differences
1) Element Types: Applicable to beam elements only.
2) Section Types and Shapes: Applicable only to specified types and shapes of sections:
Type 1 (USER): H, B
Type 2 (COMPOSITE): B, I, Tub, GB, GI, GT
Type 3 (PSC): 1CELL, 2CELL, 3CELL, NCEL, NCE2, PSCM, PSCI, PSCH, PSCT, PSCB, VALUE
3) The Section/Slab height values are used for example calculations. The load is recalculated and applied based on the specific selected element section.
4) Minimum Section Height by Superstructure Type:
The minimum applicable section height varies depending on the superstructure type:
Type 1: 600 mm
Type 2: Slab height + 400 mm
Type 3: ≥ 135 mm
Conclusion
his plugin enables you to efficiently analyze the thermal actions acting on the bridge structure, providing accurate data based on SDM 2013 for a well-informed design process.