Laminated composites have important applications in modern aeronautical structures due to their extraordinary mechanical and environmental behaviour. Nevertheless, aircraft composite structures are highly vulnerable to impact damage, either by low-velocity sources during maintenance or high-velocity sources during in-flight events. Even barely visible impact damage induced by low-velocity loading, substantially reduces the residual mechanical performance and the safe-service life of the composites structures. Despite the extensive research already carried out, impact damage of laminated composite structures is still not well understood and it is an area of on-going research. Numerical modelling is considered as the most efficient tool as compared to the expensive and time-consuming experimental testing. In this paper, a finite element model based on explicit dynamics formulations is adopted. Hashin criterion is applied to predict the intra-laminar damage initiation and evolution. The numerical analysis is performed using the ABAQUS ® programme. The employed modelling approach is validated using numerical results found in the literature and the presented results show an acceptable correlation to the available literature data. It is demonstrated that the presented model is able to capture force-time response as well as damage evolution map for a range of impact energies.
Amidst escalating environmental and social challenges, this study explores regenerative business models’ definition and characteristics. While sustainable models have made considerable strides in research, policy, and practice, the advent of regenerative business models offers a progressive leap forward. Regenerative business models aspire to contribute to ecological restoration and societal well-being. The regenerative business model concept is, however, still in its infancy and lacks a comprehensive definition. Our study aims to expand this knowledge, using a Delphi-inspired approach that builds on the knowledge of academic and business experts. Our approach includes three rounds of surveys: an open-ended survey, a survey for rating and ranking the earlier responses of all participants, and a final survey to select key characteristics. We investigate patterns and distinctions among regenerative, regenerative business, and regenerative business models, and analyze their positioning vis-a-vis circular and net-positive models. Findings underscore that organizations adopting regenerative business models focus on planetary health and societal well-being. They generate value across multiple stakeholder levels, including nature, societies, customers, suppliers, shareholders, and employees. Despite overlapping with circular and net-positive models, regenerative business models also emphasize interdependencies between humans and nature, and provide a more holistic approach, centered on restoration rather than mere mitigation.
This paper seeks to make a contribution to business model experimentation for sustainability by putting forward a relatively simple tool. This tool calculates the financial and sustainability impact based on the SDG’s of a newly proposed business model (BM). BM experimentation is described by Bocken et al. (2019) as an iterative-multi-actor experimentation process. At the final experimentation phases some form of sustainability measurement will be necessary in order to validate if the new proposed business model will be achieving the aims set in the project. Despite the plethora of tools, research indicates that tools that fit needs and expectations are scarce, lack the specific focus on sustainable BM innovation, or may be too complex and demanding in terms of time commitment (Bocken, Strupeit, Whalen, & Nußholz, 2019a). In this abstract we address this gap, or current inability of calculating the financial and sustainability effect of a proposed sustainable BM in an integrated, time effective manner. By offering a practical tool that allows for this calculation, we aim to answer the research question; “How can the expected financial and sustainability impact of BMs be forecasted within the framework of BM experimentation?
Climate change adaptation has influenced river management through an anticipatory governance paradigm. As such, futures and the power of knowing the future has become increasingly influential in water management. Yet, multiple future imaginaries co-exist, where some are more dominant that others. In this PhD research, I focus on deconstructing the future making process in climate change adaptation by asking ‘What river imaginaries exist and what future imaginaries dominate climate change adaptation in riverine infrastructure projects of the Meuse and Magdalena river?’. I firstly explore existing river imaginaries in a case study of the river Meuse. Secondly, I explore imaginaries as materialised in numerical models for the Meuse and Magdalena river. Thirdly, I explore the integration and negotiation of imaginaries in participatory modelling practices in the Magdalena river. Fourthly, I explore contesting and alternative imaginaries and look at how these are mobilised in climate change adaptation for the Magdalena and Meuse river. Multiple concepts stemming from Science and Technology Studies and Political Ecology will guide me to theorise the case study findings. Finally, I reflect on my own positionality in action-research which will be an iterative process of learning and unlearning while navigating between the natural and social sciences.
A series of tests performed on as-built and strengthened timber joist-masonry-wall specimens. The test aims at providing a complete characterization of the behaviour of the timber-joist connections under axial cyclic loading. The obtained results will be used as inputs to calibrate numerical models to simulate the connection between the cavity wall and timber joist.
The Ph.D. candidate will investigate the seismic response of connection details frequently used in traditional Dutch construction practice, specifically in the Groningen area. The research will focus on the experimental and numerical definition of the complete load-deflection behaviour of each considered connection; specifically, the tests will aim at identifying stiffness, strength, ductility, and dissipative behaviour of the connections. The experiments will be conducted on scaled or full-scale components that properly resemble the as-built and retrofitted as well connection details. The tests will involve monotonic and cyclic loading protocols to be able to define the load and displacement response of the connection to reversal loads, such as earthquakes, as well as the development of failure mechanisms under such loading cases. Possibly, also dynamic tests will be performed. Numerical models will be created and calibrated versus the experimental findings. Characteristic hysteretic behaviours of the examined connection types will be provided for the use of engineers and researchers.
