Simulation technology that protects buildings and infrastructure can be beneficial for the bottom line, prevent legal issues, and even save lives.
The future of engineering is being shaped by the rapidly evolving application of technologies such as machine-learning, virtual reality and simulations of synthetic environments.
To remain relevant, avoid disruption and constantly innovate, it’s important that engineers adopt these technologies.
Results from modelling and simulation offer greater clarity and therefore create a powerful environment for properly informed decision-making. To demonstrate its application, this article outlines two very different uses for modelling and simulation around buildings and infrastructure.
Many people don’t give a great deal of thought to wind-driven rain (WDR) until they discover their insurance policy doesn’t cover the damage it can cause.
Planning for WDR is not just about insurance, though. It is also about usability, safety and comfort for the users of the building, as well as lessee security.
Consider above-ground railway stations. They are typically designed for natural ventilation to increase user comfort. However, when it rains, stations can suffer water ingress, which affects staff, customers and business owners.
An approach to minimising, if not preventing, such issues is to use computational fluid dynamics (CFD) modelling and simulation.
The objective is to determine the effectiveness of a building’s weather protection features, while maintaining the effectiveness of its natural ventilation capability.
Modelling shows where rain can penetrate and how effective louvres might be in keeping rain out while bringing air in.
The approach models four rain droplet sizes, each with its own terminal velocity and drag coefficient, and simulates prevailing wind in eight directions.
The effect of approaching trains can be factored in, as can the impact of neighbouring buildings, including the effect of removing existing neighbouring buildings.
From here, the results from the worst two scenarios can be employed to fine-tune the station’s design. This helps a design engineer achieve a balance between the ingress of WDR and passenger experience.
If conducted during the design phase, CFD can prevent costly reworking of the station.
Terrorism is an increasing concern, particularly in city centres and around government and military buildings. Nonetheless, many buildings are constructed based on building codes that lack design considerations intended to prevent or mitigate the impact of an explosive blast.
One approach to enhancing a building’s protection features is to use a conventional table and chart method employing a set of loosely defined measures to estimate blast effects.
A second method uses modelling and simulation technology to accurately predict blast effects.
The table and chart method is designed as a one-size-fits-all, aiming to cover as many building features, sizes, shapes and scenarios as possible.
This, however, may lead to under or over-estimation.
Despite this shortcoming of the table and chart method, it is still useful for providing instant estimations.
On the other hand, the modelling and simulation method offers a bespoke assessment specific to a building’s features and to particular scenarios — the location, intensity or duration of the explosive charge, for instance — and therefore delivers more accurate results.
While the benefits of the modelling and simulation method are obvious, a drawback of this method is that it can take longer to obtain results.
Thus, a balanced approach combines two methods: the table and chart method for quick, preliminary evaluations and to shortlist the most likely scenarios, and the modelling and simulation method to assess those shortlisted scenarios and obtain more accurate results.
By combining the two methods, engineers can, within a reasonable time frame, perform blast effects analysis to obtain information around design and cost to protect against a particular level of threat.
What is involved?
Some large firms might want to purchase the modelling software and employ a specialist to run simulations, improve designs and produce reports.
Others will likely find it more feasible to outsource, as they might only have to run a simulation three or four times each year.
A consultant requires two to four weeks to gather the necessary information, develop the 3D model, run the simulation and write up a report.
However it is carried out, modelling and simulation is a powerful investment in a project and has positive outcomes for all stakeholders.
A typical application of the modelling and simulation method is blast effects analysis, which relies on the principle of fluid structure interaction (FSI).
FSI involves studying the interaction between a blast wave and the building structures.
Factors such as proximity to neighbouring buildings, building shape, orientation, height, wall thickness, age, concrete compressive and tensile strengths, and more are factored into the model.
Results will show the degree and location of damage on this and neighbouring buildings, the effects of types of reinforcement in concrete, the value of specific types of hardware such as particular door frames, and what it will take to ensure the safety of those inside.