A parametric investigation into the development of cold formed steel free form grid shells

In recent years, the adoption of parametric design approaches to geometric modelling allows to describe and investigate large complex systems with few variables [1]. Form finding techniques such as the force density and dynamic relaxation methods help in defining efficient free form structures [2]. There is therefore potential to design free form grid shells which can be optimized for basic parameters like support conditions, grid topology, load conditions, material and section properties. This work explores the possibility to use cold-formed steel section for free form shells, making advantage of their structural efficiency and versatility that allows the realization of light constructions. Three free form shells, having different geometries, configurations and grid topology, are investigated, and the viability of adopting cold formed steel members to create lightweight and stable grid shells through parametric modelling is analysed

Energy retrofit approach towards a multi-performance renovation of existing buildings

The increasing concerns over population growth, depletion of natural resources and global warming as well as catastrophic natural events is leading the international scientific community to envisage sustainability as a crucial goal. The built environment plays a key role on the triple bottom line of the sustainable development - Planet, People, Profit - because of several environmental, social and economic impacts produced by the construction sector. The acknowledged need to promote a sustainable building market is an international high-priority issue as underlined by the 2030 Agenda for Sustainable Development. Indeed one of its strategic objectives highlights to make cities and human settlement inclusive, safe, resilient and sustainable. In line with the 2020 Europe Strategy and the European 2050 Roadmap, energy efficiency and CO2 savings towards a low-carbon economy are regarded as ambitious objectives to be achieved for both new and existing buildings. Thus energy retrofit becomes a fundamental and growing research area to be investigated. This study aims to investigate the opportunity to develop sustainable integrated renovations that can improve energy and structural performance and at the same time provide economic and social benefits. A brief overview on the main characteristics and criticalities of the EU existing residential building stock is introduced. The work emphasizes the possibility to use envelope retrofit practice based on prefabricated modules as a potential measure to optimize the energy performance and increase occupants’ comfort and economic property value. The benefits of the investigated solutions are evaluated according to a multi-performance life-cycle oriented approach. Finally, a discussion on the possibility to apply the proposed methodology to residential high rise buildings in Leeds is exposed

A digital design process for shell structures

Over the last few decades, the design of freeform structures has undergone a radical change: powerful computational tools within parametric environment associated with digital fabrication techniques are pushing the boundaries of architecture towards bold solutions. The present work proposes a digital workflow for a shell in compression. The design process starts with the form-finding phase, which generates a hanging model. Through the interoperability of digital tools within parametric environment, optimization of the shape and structural analysis were carried out in order to investigate its behavior. The resulting surface is subject to tessellation, planarization of its cells that take into account fabrication constrains, and the 3D generation of panels composing the thickness of the structure. In order to accomplish an easier assembly process a hypothesis of a puzzle-like connection system was developed. The whole process provides a guidance for the design of freeform shell by the creation of a “customized” digital workflow implemented by digital fabrication techniques for the realization phase

Energy retrofit of tower blocks in UK: making the case for an integrated approach

Tower blocks in UK are at a critical stage. They were built at a time when no energy efficiency requirements were considered. They are now approaching the end of their design service life and they are damp, and cold place to live. Starting from the analysis about the diffusion of multi-storey buildings in EU, and the findings of other research projects such as INSPIRE and Faro, this work debates the strategies applied for energy efficiency improvement of large panel concrete buildings. This work debates the structural retrofit that in many cases are required prior to any energy retrofit intervention and draw the attention on the necessity to develop more holistic retrofit approaches, aiming to the development of best practice for energy, safety and social benefits

The application of free-form grid shells as protective shelters in archaeological sites

The challenge of preserving archaeological sites by the adoption of grid shells is investigated in this paper. Archaeological remains often require protection from external agents, especially environmental threats. In fact, when covered by soil, they are preserved effectively under certain equilibrium conditions. Nonetheless, when exposed to the outer environment they can easily deteriorate. Therefore, a shelter or enclosure may be provided for protection. When a large area requires protection, steel structures such as portal frames or two-dimensional trusses are extensively employed. These have a heavyweight character and require deep foundations, the construction of which is substantially limited in archaeological sites, and increases the risk of damage during erection. Through the development of an extensible free-form grid shell design with a minimum weight, maximum stiffness and constructability approach, the potential application of shelters for archaeological sites is evaluated. This study involves a parametric investigation and considers the worst-case scenario conditions

Robust computation of the observability of large linear systems with unknown parameters

The concept of observability plays an important role in structural health monitoring as it can be utilized to theoretically predict whether the system identification of a structure of interest may be successful. The Observability Rank Condition (ORC) is an efficient tool used for analyzing the observability of dynamical systems. However, there are practical constraints, in terms of processing speed and computer memory, in implementing the ORC for large systems, or systems with complicated equations. In this work, a robust approach to compute the observability matrix of linear systems with unknown parameters is proposed. The newly developed algorithm is capable of handling a linear system of substantially larger order than the original algorithm

Future scenarios for housing (re)settlements in Ecuador

Post-earthquake (re)settlements are too often the results of political decisions, driven by the urgency of housing survivors in emergency. There is very limited evidence of strategic decisions made for the long-term wellbeing of the displaced communities. This has certainly been the case, for the post-earthquake reconstructions developed in the aftermath of the 2016 Muisne earthquake in Ecuador. Previous research has indeed demonstrated, through qualitative empirical research, the failure of the developed resettlements from both a technical and a social perspective. This paper aims to re-think the way to conceive (re)settlements with the aim to co-produce with local experts and inhabitants possible future scenarios. A first pilot case, that adopts design solutions at the urban and housing unit level, which are strongly connected to the local geographic and cultural context, is discussed. This paper presents and discusses the design evolution of the proposed pilot case, posing the attention to the urban development and the housing design, articulated imagining the (re)settlement as a new neighbourhood of the city, with a combination of private and public spaces, that will grow and be fully integrated to the consolidated city as population grow

Using bolted connections for the construction, de-construction and reuse of lightweight exterior infill walls: Experimental study

Data availability The data that support the findings of this study are available from the corresponding author upon reasonable request.Bolted connections offer advantages in terms of disassembly and reusability, potentially replacing conventional connections like screws, welds, or chemical bonds. This research investigates the behaviour of bolted connections between lightweight exterior infill walls and beams of primary structural members that are conventionally connected using screws. Although previous studies have investigated bolted connections in different structural members, understanding of the behaviours of these specific connections remains limited. The connections between infill walls and steel beams primarily experience shear loads under serviceability conditions. Therefore, an experimental study was conducted to gain insight into their shear behaviour. The obtained experimental results were analysed using existing predictive equations from design standards that are used across European, North American and Oceanian countries, to identify the most suitable equations for designing such connections.EPSRC through the Interdisciplinary Circular Economy Centre for Mineral-Based Construction Materials from the UK Research and Innovation (EPSRC Reference: EP/V011820/1)

Retrofitting Masonry Walls against Out-Of-Plane Loading with Timber Based Panels

Unreinforced masonry walls are prone to failure when subjected to out-of-plane loading. This is due to their low performance in bending, and often the lack of appropriate connection to returning walls and floors. This paper investigates the possibility to use oriented strand boards (OSB) panels to improve the out-of-plane performance of brick masonry walls. The proposed technique considers securing OSB type-3 panels behind masonry walls with chemical and mechanical connections. The work presents finite element models to predict their behaviour. The models have been calibrated and validated through a three-phase experimental campaign, aimed at (a) characterizing the main structural components, (b) studying the out-of-plane behaviour of small-scale masonry prisms and (c) studying the behaviour of 1115 × 1115 × 215 mm masonry walls. The finite element models developed are based on a micromodel technique developed in ABAQUS and demonstrated to adequately capture the behaviour of both plain and retrofitted models to the ultimate load. The models also show an excellent correlation of the compressive damage and tensile damage with the experimental failure pattern. Generally, the model predicted the peak load and the corresponding failure and toughness to within less than 10% of the average test results