Periodic Reporting for period 2 - LIGHTEN (Ultralight membrane structures towards a sustainable environment)
Reporting period: 2022-11-01 to 2025-04-30
The building construction industry is the largest anthropogenic source of pollution, with massive energy consumption and substantial CO2 emissions. Lightweight membrane structures enable the simultaneous implementation of multiple sustainable strategies by utilising recyclable, low-carbon structural membranes. Their efficient structural load-bearing mechanisms result in significant weight savings in buildings and a substantial reduction in the environmental impact associated with material production, transportation, use, and disposal. Structural fabrics and foils have gained popularity among designers and architects due to their desirable features, including high stiffness, strength, ductility, durability, and functional properties. Whilst these structural membranes open up new, crucial perspectives for the clean energy transition and have been recently employed worldwide, their full potential is still limited by the lack of construction codes, advanced optimisation tools, and comprehensive knowledge of their thermo-mechanical response.
Therefore, the LIGHTEN project aims to train a new generation of PhD students to become experts in advanced design methods for a sustainable built environment through ultralightweight membrane structures.
Building constructions and operations show the highest environmental footprint in terms of global energy consumption and CO2 emissions. The carbon footprint of construction is increasing, with almost one-third of building-related CO2 emissions due to the use of materials. The demand for buildings, floor area and construction materials is growing and expected to double by 2060. Under these circumstances, innovative building technologies employing low-carbon materials are of paramount importance to lower construction-related CO2 emissions through (i) resource-efficient lightweight building designs, (ii) waste reduction via reuse and recycling, (iii) lifetime extension, and (iv) minimal transportation. Hence, the primary challenge in the building sector is identifying and implementing innovative construction technologies.
A feasible solution for achieving a sustainable built environment is offered by membrane, or tensile, structures. Recyclable lightweight membranes offer a thinner and greener alternative to glass and other transparent cladding materials, resulting in significant weight savings. They are advantageous in scenarios where the design must accommodate large unsupported spans with minimal weight. By building better with less material, environmental benefits in the form of reduced energy usage and carbon emissions during production, transportation and installation could be accrued, while simultaneously providing a cost-effective engineering solution.
LIGHTEN aims to foster ultralightweight membrane structures by developing engineering models capable of predicting and optimising their response and performance. The research objectives, which have been achieved through a combination of analytical, numerical and experimental methods, are: (i) characterisation and modelling of the nonlinear thermo-visco-elasto-plastic response of ETFE membranes, (ii) analyses of failure and instabilities of structural thin films and (iii) design and machine-learning optimisation of lightweight structural elements.
The project's outcomes provide new insights into the development of design approaches and building standards for sustainable membrane structures. The objectives have been achieved by equipping research students with a balanced combination of original research abilities, transferable skills, technical, and industry-oriented knowledge, which maximises their employability in a European market that requires enhanced technological competencies to face the current challenges of the sustainable built environment.
Therefore, the LIGHTEN project aims to train a new generation of PhD students to become experts in advanced design methods for a sustainable built environment through ultralightweight membrane structures.
Building constructions and operations show the highest environmental footprint in terms of global energy consumption and CO2 emissions. The carbon footprint of construction is increasing, with almost one-third of building-related CO2 emissions due to the use of materials. The demand for buildings, floor area and construction materials is growing and expected to double by 2060. Under these circumstances, innovative building technologies employing low-carbon materials are of paramount importance to lower construction-related CO2 emissions through (i) resource-efficient lightweight building designs, (ii) waste reduction via reuse and recycling, (iii) lifetime extension, and (iv) minimal transportation. Hence, the primary challenge in the building sector is identifying and implementing innovative construction technologies.
A feasible solution for achieving a sustainable built environment is offered by membrane, or tensile, structures. Recyclable lightweight membranes offer a thinner and greener alternative to glass and other transparent cladding materials, resulting in significant weight savings. They are advantageous in scenarios where the design must accommodate large unsupported spans with minimal weight. By building better with less material, environmental benefits in the form of reduced energy usage and carbon emissions during production, transportation and installation could be accrued, while simultaneously providing a cost-effective engineering solution.
LIGHTEN aims to foster ultralightweight membrane structures by developing engineering models capable of predicting and optimising their response and performance. The research objectives, which have been achieved through a combination of analytical, numerical and experimental methods, are: (i) characterisation and modelling of the nonlinear thermo-visco-elasto-plastic response of ETFE membranes, (ii) analyses of failure and instabilities of structural thin films and (iii) design and machine-learning optimisation of lightweight structural elements.
The project's outcomes provide new insights into the development of design approaches and building standards for sustainable membrane structures. The objectives have been achieved by equipping research students with a balanced combination of original research abilities, transferable skills, technical, and industry-oriented knowledge, which maximises their employability in a European market that requires enhanced technological competencies to face the current challenges of the sustainable built environment.
The project management, Work Package (WP) 8, has seen the signature of the consortium agreement (D8.1) the appointment of the supervisory board (D8.2) the data management plan (D8.3) the achievement of the project check (D8.4 milestone MS5), and assessment of the annual reports (D8.5).
The recruitment of five Early Stage Researchers (ESRs) was completed (D1.1 MS1) in WP1. Each ESR enrolled in a PhD programme (MS22), and a career development plan was signed (D6.1 MS2).
The research activities of WPs 2, 3, 4, and 5 have been delivered by the ESRs, who defined testing protocols (D2.1) that enabled thermo-visco-elasto-plastic characterisation of structural membranes (D2.2 D2.3 MS6), established novel procedures for assessing yield strength (D3.2 MS8), and analytically developed and numerically implemented (D5.1 D5.2 MS12) constitutive models (D2.4 D3.4 MS7, MS9) and yield criteria (D3.3 MS10) required in the design of membrane structures (D5.4 MS15). A comprehensive literature review on membrane failure and instabilities was conducted (D3.1) setting up analyses on wrinkling and flutter instabilities (MS14) to support design approaches under extreme conditions (D5.3 MS13). Data-driven methods were also developed (D4.1 D4.2 MS11) to establish hybrid machine-learning (ML) constitutive models (D4.3) and ML-based topology optimisation method (D4.4).
Network-wide scientific and complementary training activities were organised in WP6, including three training schools (MS3), two workshops (D7.3) and soft skills events. These complemented the training ESRs received from academic and industrial supervisors (D6.2). The training and research were instrumental for progress (D6.3 MS16) toward PhD completion (D6.4 MS21).
The consortium also established a Communication, Outreach, Dissemination and Exploitation plan in WP7 (D7.2). The LIGHTEN website was created (D7.1 MS4) in conjunction with social media channels. ESRs participated in outreach events (MS19), disseminated results to the scientific community (D7.4 MS17), and attended international conferences (MS18). Exploitation activities have begun with academic and industrial stakeholders (MS20).
The recruitment of five Early Stage Researchers (ESRs) was completed (D1.1 MS1) in WP1. Each ESR enrolled in a PhD programme (MS22), and a career development plan was signed (D6.1 MS2).
The research activities of WPs 2, 3, 4, and 5 have been delivered by the ESRs, who defined testing protocols (D2.1) that enabled thermo-visco-elasto-plastic characterisation of structural membranes (D2.2 D2.3 MS6), established novel procedures for assessing yield strength (D3.2 MS8), and analytically developed and numerically implemented (D5.1 D5.2 MS12) constitutive models (D2.4 D3.4 MS7, MS9) and yield criteria (D3.3 MS10) required in the design of membrane structures (D5.4 MS15). A comprehensive literature review on membrane failure and instabilities was conducted (D3.1) setting up analyses on wrinkling and flutter instabilities (MS14) to support design approaches under extreme conditions (D5.3 MS13). Data-driven methods were also developed (D4.1 D4.2 MS11) to establish hybrid machine-learning (ML) constitutive models (D4.3) and ML-based topology optimisation method (D4.4).
Network-wide scientific and complementary training activities were organised in WP6, including three training schools (MS3), two workshops (D7.3) and soft skills events. These complemented the training ESRs received from academic and industrial supervisors (D6.2). The training and research were instrumental for progress (D6.3 MS16) toward PhD completion (D6.4 MS21).
The consortium also established a Communication, Outreach, Dissemination and Exploitation plan in WP7 (D7.2). The LIGHTEN website was created (D7.1 MS4) in conjunction with social media channels. ESRs participated in outreach events (MS19), disseminated results to the scientific community (D7.4 MS17), and attended international conferences (MS18). Exploitation activities have begun with academic and industrial stakeholders (MS20).
LIGHTEN is the first doctoral programme to offer advanced skills in lightweight membrane materials and structures. The research activities have advanced the state of the art, including (i) a comprehensive experimental campaign to characterise ETFE membranes in thermomechanical ranges not previously explored, (ii) a novel imaging technique to assess plasticity onset in structural membranes, (iii) the development of new thermo-visco-elastoplastic constitutive models for ETFE foils, with open-source implementation and comparison to existing standards, (iv) the discovery of restabilisation after wrinkling instabilities, (v) the analysis of flutter and aerodynamic instabilities in membrane structures, (vi) an open-source data-driven framework for analysing materials and structures, (vii) hybrid machine learning approaches for constitutive modeling, and (viii) a neural topology optimisation method for lightweight design.
Project impact includes (i) training five doctoral students, (ii) establishing new scientific knowledge published in international journals, proceedings, and a book chapter, and (iii) increased awareness of the benefits of lightweight sustainable constructions through outreach activities. Beyond its scientific results, the project is expected to have a positive impact on society and support the United Nations’ Sustainable Development Goals 11 and 12.
Project impact includes (i) training five doctoral students, (ii) establishing new scientific knowledge published in international journals, proceedings, and a book chapter, and (iii) increased awareness of the benefits of lightweight sustainable constructions through outreach activities. Beyond its scientific results, the project is expected to have a positive impact on society and support the United Nations’ Sustainable Development Goals 11 and 12.