sfeprapy 0.6.4

Structural Fire Engineering - Probabilistic Reliability Assessment

SfePrapy

A probabilistic analysis tool that estimates the structural reliability for a given scenario (such as enclosure geometry, building type, window areas etc.) against equivalent time exposure to the ISO 834 fire curve.

Getting Started

These instructions will get you a copy of the project up and running on your local machine for development and testing purposes.

Python 3.7 or later is required.

Installation

pip

pip is a package management system for installing and updating Python packages. pip comes with Python, so you get pip simply by installing Python. On Ubuntu and Fedora Linux, you can simply use your system package manager to install the python3-pip package. The Hitchhiker's Guide to Python provides some guidance on how to install Python on your system if it isn't already; you can also install Python directly from python.org. You might want to upgrade pip before using it to install other programs.

1. If you are using Windows with Python version 3.3 or higher, use the Python Launcher for Windows to use pip with Python version 3:

   py -3 -m pip install SfePrapy
   

2. If your system has a python3 command (standard on Unix-like systems), install with:

   python3 -m pip install SfePrapy
   

3. You can also just use the python command directly, but this will use the current version of Python in your environment:

   python -m pip install SfePrapy
   

Usage

MCS for structural PRA method 0: sfeprapy.mcs0

Introduction of sfeprapy.mcs0 is current NOT covered here but will provide notebook tutorials in near future.

To run sfeprapy.mcs0 from source (or when it is installed via, i.e. pip):

python -m SfePrapy.mcs0

A window will be popped up asking for input a input / problem definition file. The input file should be in '.csv' or '.xlsx' format. Structure of the input file is addressed in the following paragraphs.

When a configuration file with the name 'config.json' is provided in the same directory, the program will attempt to read it and use parameters contained therein. Number of threads (multi-processing) along with few other parameters can be defined in this file.

Once the input file is selected, the program will take the lead and run calculations until all simulations are complete. Results will be saved in the same folder. Conveniently, the software has the feature of displaying the progress and some statistics as per below.

CASE                    : Standard Case 1
NO. OF THREADS          : 4
NO. OF SIMULATIONS      : 1000
100%|███████████████████| 1000/1000 [00:09<00:00, 86.15it/s]
fire_type               : {0: 23, 1: 977}
beam_position_horizontal: -1.000    27.534    28.646   
fire_combustion_efficien: 0.800     0.900     1.000    
fire_hrr_density        : 0.240     0.250     0.260    
fire_load_density       : 10.000    420.399   1500.000 
fire_nft_limit          : 623.150   1323.150  2023.152 
fire_spread_speed       : 0.004     0.011     0.019     

CASE                    : Standard Case 2
NO. OF THREADS          : 4
NO. OF SIMULATIONS      : 1000
100%|███████████████████| 1000/1000 [00:10<00:00, 77.85it/s]
fire_type               : {0: 10, 1: 990}
beam_position_horizontal: -1.000    27.943    28.646   
fire_combustion_efficien: 0.800     0.900     1.000    
fire_hrr_density        : 0.240     0.250     0.260    
fire_load_density       : 10.000    420.399   1500.000 
fire_nft_limit          : 623.150   1323.150  2023.152 
fire_spread_speed       : 0.004     0.011     0.019   

Input Parameters

Example input template can be found at:

• sfeprapy.mcs0.EXAMPLE_CONFIG_DICT: Example configuration file, dict object;
• sfeprapy.mcs0.EXAMPLE_INPUT_DICT: Example input file, dict object; and
• sfeprapy.mcs0.EXAMPLE_INPUT_CSV: Example input file, str in csv format.

The following table summerises the parameters that are required by sfeprapy.mcs0 module.

PARAMETERS	DESCRIPTION
Model Settings
case_name	Str. An unique name indicating a case. This maybe used in post-processing when combining time equivalence results.
fire_mode	Integer. To define what design fires to use: 0 - EC parametric fire only; 1 - Travelling fire only; 2 - EC parametric fire, German Annex; 3 - Option 0 and 1 as above; and 4 - Option 2 and 2 as above.
n_simulations	Integer. The number of simulations that will be running. A sensitivity analysis should be carried out to determine the appropriate number of simulations.
probability_weight	Float. The fire occurance probability weight of this specific case (i.e. compartment) among all cases (i.e. entire building). sfeprapy.mcs0 does not use this parameter for any calculation, it is only used during post-processing phrase.
Compartment Geometry
room_breadth	Float, in [m]. Breadth of room (greater dimension).
room_depth	Float, in [m]. Depth of room (shorter dimension).
room_height	Float, in [m]. Height of room (floor slab to ceiling slab).
window_width	Float, in [m]. Total width of all opening areas for a compartment.
window_height	Float, in [m]. Weighted height of all opening areas.
beam_position_vertical	Float, in [m]. Height of test structure element within the compartment for TFM. This can be altered to assess the influence of height in tall compartments. Need to assess worst case height for columns.
beam_position_horizontal	Float, in [m]. Minimum beam location relative to compartment length for TFM - Linear distribution
Windows/Natural Vent
window_open_fraction	Float. Glazing fall-out fraction.
window_open_fraction_permanent	Float. Use this to force a ratio of open windows. If there is a vent to the outside this can be included here.
Fire inputs
fire_tlim	Float, in [hour] Time for maximum gas temperature in case of fuel controlled fire. Slow: 25/60 Medium: 20/60 Fast: 15/60 (Annex A EN 1991-1-2)
fire_time_step	Float, in [s]. Time step used for the model, all fire time-temperature curves and heat transfer calculation. This is recommended to be less than 30 s.
fire_time_duration	Float, in [s]. End of simulation. This should be set so that output data is produced allowing the target reliability to be determined. Not always necessary to main_args for extended periods. Normally set it to 4 hours and longer period of time for greater room length in order for travelling fire to propagate the entire room.
room_wall_thermal_inertia	Float, in [J/m²/K/√s]. Compartment lining thermal inertia.
fire_load_density	Float, in [MJ/m²]. Fire load density. This should be selected based on occupancy charateristics. See literature for typical values for different occupancies.
fire_hrr_density	Float, in [MW/m²]. Heat release rate. This should be selected based on the fuel. See literature for typical values for different occupancies.
fire_spread_speed	Float, in [MJ/m²]. Min spread rate for TFM.
fire_nft_limit	Float, in [°C]. TFM near field temperature.
fire_combustion_efficiency	Float, in [-]. Combustion efficiency.
fire_gamma_fi_q	Float, in [-]. The partial factor for EC fire (German Annex).
fire_t_alpha	Float, in [s]. The fire growth factor.
Section Properties
beam_cross_section_area	Float, in [m²]. Cross sectional area of beam
beam_rho	Float, in [kg/m³]. Density of beam
beam_temperature_goal	Float, in [K]. Beam (steel) failure temperature in kelvin for goal seek
protection_protected_perimeter	Float, in [m]. Heated perimeter
beam_protection_thickness	Float, in [m]. Thickness of protection
protection_k	Float, in [W/m/K]. Protection conductivity
protection_rho	Float, in [kg/m³]. Density of protection to beam
protection_c	Float, in [J/kg/K]. Specific heat of protection
Solver Settings
solver_temperature_goal	Float, in [K]. The temperature to be solved for. This is critical temperature of the beam structural element, i.e. 550 or 620 °C.
solver_max_iter	Float. The maximum iteration for the solver to find convergence. Suggest 20 as most (if not all) cases converge in less than 20 iterations.
solver_thickness_lbound	Float. The smallest value that the solved protection thickness can be.
solver_thickness_ubound	Float. The greatest value that the solved protection thickness can be.
solver_tol	Float, in [K]. Tolerance of the temperature to be solved for. Set to 1 means convergence will be satisfied when the solved value is within solver_temperature_goal-1 and solver_temperature_goal+1.

##Limitations

Todo

Authors

• Yan Fu - [e-mail]
• Danny Hopkin - [e-mail]
• Ieuan Rickard - [e-mail]

License

This project is licensed under the MIT License - see the LICENSE file for details