The significance of structural performance under fire conditions is escalating in the realm of modern architecture. Building regulations, exemplified by Technical Booklet E in Northern Ireland and Approved Document B in England, articulate performance requirements without dictating specific methodologies.
Fire design, therefore, relies on documents such as these, where tables delineate ‘minimum periods of fire resistance’ based on building purpose and height.
A robust analytical procedure is imperative to ensure structures meet regulatory standards during a fire. The fire design segments in the Structural Eurocodes – EN1991-1-2, EN1992-1-2, EN1993-1-2, and EN1995-1-2 – offer calculation types among tabular, simple and advanced. As architectural demands evolve and the emphasis on cost and carbon emission reduction intensifies, advanced methods are gaining traction.
Fire Design with AxisVM
Effectively applying advanced methods necessitates a contemporary structural engineering analysis tool that accommodates diverse analyses. AxisVM excels in advanced linear, non-linear, dynamic, and seismic analyses, including fire design.
Whether working on models created from scratch, imported from popular platforms like Revit or Tekla through BIM links, or extracted from IFC files, AxisVM ensures a seamless workflow. Designers can even engage with parametric models from Grasshopper or Dynamo, facilitated by intuitive dialogs guiding them through the intricacies of defining fire design loads and analysis parameters.
Now, let’s delve deeper into the capabilities for each supported building material:
AxisVM aligns with EN1992-1-2 for concrete structures. It comprehensively assesses members under fire conditions, supporting prescribed fire curves.
The software swiftly evaluates temperature distribution for each member, accounting for reduced section resistance due to surface damage and reduced strength at elevated temperatures. It considers the diminished resistance of the concrete member facilitating required reinforcement calculations or assessment of provided reinforcement designed in other limit states.
Figure 1: Fire curve, temperature distribution and modified interaction curve for concrete column.
The steel design module corresponds to EN1993-1-2. Beyond prescriptive and parametric fire curves, AxisVM allows users to declare custom fire curves for precise simulations according to experimental or advanced numerical results.
The software calculates the temperature distribution of steel members through the code prescribed formulas or even by solving heat transfer equations. Identifying critical temperatures aids in determining the necessity for fire protection and its type, potentially leading to cost-effective and environmentally friendly solutions.
Figure 2: Fire curve, heat distribution for I section and critical temperature diagrams.
AxisVM evaluates timber members according to EN1995-1-2. The approach to fire effects mirrors previous cases, employing the reduced cross-section method. This involves determining effective charring depth and reducing the cross-section depth at exposed sides.
AxisVM accommodates variations in buckling lengths of stabilising members under fire compared to other limit states, empowering users to define different coefficients.
Figure 3: Fire curve, exposure settings for timber members and calculation report for the fire situation.
For structural engineers, whether graduates exploring structural design or experienced professionals navigating tight project timelines, AxisVM emerges as the quintessential tool. With its simplicity, reliability, intuitiveness, and transparency, AxisVM has managed to grow a user base of 8,000 companies worldwide.
The software adapts to industry trends, incorporating features like soil-structure interaction and the import of wind actions determined by advanced CFD models.
With all this mind, it has the potential to become your preferred design tool, providing a flexible and robust platform to meet all your structural design requirements.
More information: www.axisvm.eu
Reseller for Ireland: www.techscience.co.uk