Mechanical behaviour of facade systems in fire

由于玻璃的外观和性能，设计师越来越多地选择玻璃外墙。玻璃立面的设计是为了抵抗重力和风荷载，并确保一定程度的安全。然而，它们在火灾事件中的热性能和机械性能没有得到规范，并且仍然知之甚少。虽然近年来人们一直在探索玻璃作为一个组件的防火性能，但很少有人关注玻璃幕墙组件作为一个整体的性能。这是因为框架、拱肩板和托架通常不像玻璃板那样容易着火。然而，这一假设尚未得到证实。金属构件很薄，因此会迅速升温，导致刚度和强度降低，从而导致过度变形。方法：我们将通过有限元计算建模软件LS-DYNA研究幕墙组件的防火性能。我们将调查的表面构件是用作框架和支撑釉面单元的铝型材。这些框架系统可以包括一些由称为“热断裂”的聚合物制成的部分。当加热时，这些聚合物部件会比铝更快地失去刚度，并最终熔化，危及整个框架系统。我们还将分析用于将立面悬挂在主体结构上的支架和机械固定装置的性能。为了验证我们的模型，我们将进行大规模的实验。这些实验将帮助我们了解构件之间的相互作用和结构作为零件组装的性能。目的：研究玻璃幕墙和双层玻璃幕墙在火灾中的表现。-识别幕墙系统可能存在的薄弱环节和失效机制。-收集信息，指导立面工程师和建筑师设计更具弹性的外墙，使其在高温下表现更好。-收集有助于理解复杂farade系统行为的实验和视觉数据。

Designers increasingly opt for glazed facades due to the appearance and performance of glass. Glazed facades are designed by regulation to resist gravity and wind loads and ensure a certain level of safety. However, their thermal and mechanical performance in a fire event is not regulated and is still poorly understood. While the fire performance of glass as a component has been explored in recent years, very little work has been focused on the behaviour of glazed facade assemblies as a whole. This is because frames, spandrel panels and brackets are generally not considered as vulnerable to fire as the glass panels. This assumption however has not been verified. The metallic members are thin and can therefore heat up rapidly, causing a reduction in stiffness and strength, which can lead to excessive deformation.MethodologyWe will study the fire performance of curtain wall assembly via the finite element computational modelling software LS-DYNA. The façade members we will be investigating are aluminium extrusions used as framing and support of the glazed units. These framing systems can include some sections made from polymers called "thermal breaks". When heated these polymer parts will lose stiffness faster than the aluminium and will eventually melt compromising the whole framing system. We will also analyse the performance of brackets and mechanical fixings used to hang the façade from the main structure. To validate our models, we will be running large scale experiment. These experiments will help us understand the interaction between members and the performance of the structure as an assembly of parts. Objectives- Investigate how glazed curtain walls and double-glazed façade perform in fire. - Identify possible weak elements and failure mechanism of curtain wall systems. - Gather information to guide façade engineers and architects in the design of more resilient facades that perform better when exposed to elevated temperatures.- Collect experimental and visual data that will help understand the behaviour of complex façade systems.