Characterising dynamic performance of fibre reinforced polymer structures for resilience and sustainability

Structural application of fibre-reinforced polymer (FRP) composite materials is one of the key factors leading to technological innovations in aviation, chemical, offshore oil and gas, rail and marine sectors. Motivated by such successes, FRP shapes and systems are increasingly used in the construction sector, such as for bridges and small residential buildings. An obstacle to a wider use of FRP materials in structural engineering is the current lack of comprehensive design rules and design standards.

While the preparation of design guidance for static actions is at an advanced stage in the USA and EU, the design against dynamic loading is underdeveloped, resulting in cautious and conservative structural design solutions. Knowledge on the dynamic properties (natural frequencies, modal damping ratios, modal masses and mode shapes of relevant vibration modes) of FRP structures and their performance under dynamic actions (such as pedestrian excitation, vehicle loading, wind and train buffeting) needs to be advanced if to achieve the full economic, architectural and engineering merits in having FRP components/structures in civil engineering works.

This project will provide a step change to design practice by developing new procedures and recommendations for design against dynamic actions. This will be achieved by: 1) Developing an instrumented bridge structure at the University of Warwick campus that will provide unique insight into both static and dynamic performance over the course of the project, and beyond; 2) Providing novel experimental data on dynamic properties and in-service vibration response of ten full-scale FRP structures; and 3) Critical evaluation of the numerical modelling and current vibration serviceability design approaches. The data collected will be delivered in a systematic form and made available, via an open-access on-line database for rapid and easy dissemination, to academic and industrial beneficiaries, as well as to agencies supporting the preparation of institutional, national and international consensus design guidance.

Outcomes from this project will provide the crucial missing information required for the reliable design of light-weight FRP structures, and pave the way towards this structural material becoming a 'material of choice' for future large-scale bridges and other dynamically loaded structures. This medium to longer-term impact is aligned with national plans for the UK having a sustainable and resilient built environment.

The research and its deliverables can provide an immediate impact within the commercial private sector working with fibre-reinforced polymer (FRP) materials for new-build applications. To take advantage of the new knowledge gained we will give oral presentations over the project's duration at, say NGCC, IStructE or MBE KTN events. The Warwick team will disseminate the final project results during a free one-day industry-focused workshop. These activities will allow the industry sector to gain new understanding and a competitive advantage in delivering (sustainable) infrastructure using FRP shapes and systems. In addition, the usual dissemination channels of journal and conference papers will be used to inform others to the opportunities they can gain from this novel research.

The Warwick team will create and maintain DynFRP, an on-line open-access database, which will store and distribute the raw field test data, the salient test results and supplementary information in technical reports. To provide the highest impact when used by others, DynFRP will have photographs, technical details of tested structures, and overviews of their modal properties and in-service vibration performances (including information about the corresponding dynamic loading). DynFRP database will not only provide an effective update on the project's progress and outcomes for structural designers and academic researchers, but also allow them to analyse the data in new ways, developing further academic and industry impacts.

There will be an impact for professional bodies overseeing the preparation of design standards and regulations. Throughout the project results will be transferred to code writers working on national and international projects (say, for a FRP structural Eurocode) to develop new and improved guidelines for a consensus design standard. Developing guidance for FRP structures exposed to dynamic actions is essential to achieving the optimum (sustainable and serviceable) solutions. The outcomes from our project will be a timely and essential addition to the on-going work (of CEN TC250) to have a Eurocode for FRP materials. Given that a 2013 report from the Composite Leadership Forum recommends that there should be "Work with appropriate bodies to facilitate the development of industry standards to support the use of composites in construction", this group are to be major beneficiaries from the project.

Industry supporters will benefit either by using the project's results as direct inputs in their future designs (e.g. SKM/Jacobs and Optima Projects Ltd.), or by establishing a knowledge base for the dynamic performance of a FRP system, such as the Startlink House (Larkfleet Homes), or by considering an FRP option on equal terms with other structural materials (e.g. Network Rail and HS2). Furthermore, those UK companies that offer protection of structures against excessive vibrations will find a positive impact to their business from detailed insight into modal properties of FRP structures that is essential to successful vibration control.

Enabling wider use of FRPs in structural engineering via this project will be of direct benefit to the society via contributing to realisation of the Government's policies on reducing carbon intensity, improving efficiency of resource exploitation and improving energy performance within infrastructure works.

There will be a longer term impact because the broader research community can benefit from having access to the new test facilities of the 15m FRP bridge on the campus at Warwick University. This will enable the Warwick team to foster collaborations that prolongs the impact well beyond the date of the project's completion.

Strategies for accelerating the impact are presented in the Pathways to Impact.