Speaker	Francesco Dal Corso (CV) Associate Professor, University of Trento, Italy
Topic	Buckling, restabilization and dynamics of extremely deformable structures subject to configurational forces (brochure)
Date	1/12/2021, 11:00
Abstract	The concept of configurational (material) force has been introduced by Eshelby to describe the motion of massless (voids, microcracks, vacancies, or dislocations) or heavy (inclusions) defects within a solid body as the result of mechanical or thermal loading. This concept has been exploited through the years for modelling the crack-driving force in fracture mechanics, the Peach–Koehler force of dislocations, or the material force developing on a phase boundary in a solid under loading. In the present work, the action of configurational forces on elastic structures are theoretically and experimentally proven in the presence of a specific movable constraint: a frictionless, perfectly smooth and bilateral sliding sleeve. Intriguing mechanical behaviours are disclosed for compliant structural systems involving configurational constraints. The following cases will be examined: (i) An elastic rod constrained by a frictionless sliding sleeve ending with a linear spring and subject to a dead load at the other end, (ii) The sudden release of a rod with a concentrated weight attached at one end and partially inserted into a frictionless sliding sleeve at the other and (iii) The periodic oscillation of a configurational constraint during the fall of a rod. The results represent innovative concepts in mechanics to be used in advanced applications, as for example in actuation mechanisms, energy harvesting, vibration mitigation, shock absorbers.

Speaker	Vassiliki Kati (CV) Professor, University of Ioannina, Head of Biodiversity Conservation lab, Ioannina, Greece
Topic	The nexus roads-windfarms-biodiversity under the light of sustainable spatial planning (brochure)
Date	22/12/2021, 11:00 (video (DIAVLOS, YouTube))
Abstract	Humanity depends directly on biodiversity and its services but we currently face both a biodiversity and a climate crisis. The lecture will focus on two topical issues: (a) Road sprawl is a key driver behind biodiversity loss. We suggest a new national and European roadless policy towards the non net-land take milestone. We present the roadless map of Greece, and we suggest the conservation in legal terms of large roadless areas as ecosystems of high natural, ecological and aesthetic value. The Greek prime minister announced the conservation of roadless areas in the world summit COP26 under the emblematic title “Untrodden Mountains”. (b) Aeolian energy is the leading renewable energy source. However, we often face the paradox of impacting on biodiversity to combat climate change. We present a novel method of spatial planning that enhances windfarm sustainability: investments are prioritized in the most fragmented zones that lie outside the Natura 2000 network of protected areas. The suggested investment zone supports wind harnessing 1.5 times higher than the 2030 national goal, having only marginally lower (4%) wind speed. The sustainable scenario provides significant benefits to biodiversity and society. It is not known if the sustainable scenario will be integrated in the forthcoming national spatial planning for renewables. More info here and here.

Speaker	Chrysi Laspidou Professor
Topic	The SIM4NEXUS Serious Game (brochure)
Date	12/1/2022, 11:00 (video (DIAVLOS, YouTube))
Abstract	A Serious Game (seriousgame.sim4nexus.eu), produced by the Eu-funded Horizon 2020 SIM4NEXUS project, will be presented. The Serious game is a computer game that aids learning about the Nexus by helping users to understand and explore the interactions between water, energy, land and food resources management under a climate change context, divides the problem into manageable interventions, and allows participants to learn by doing. It is built upon system dynamics models with a sound scientific basis. The ultimate goal of game development is to create a fun and interactive capacity-building tool to be used in research, educational settings and management. The Serious Game enables players to implement policies in a gameplay environment and explore how policies impact on different Nexus components. Summary information is given about policy actions, assigned costs and potential benefits; this facilitates scorekeeping according to both financial and social capital metrics. Costs are tallied against benefits, which are revealed as gameplay progresses. This allows a player to measure progress and compare to others. The Serious game includes a strategy map that facilitates comparison of policy impacts in different regions, a virtual card table in which policy cards can be applied through a drag-and-drop interface, and a visualization system that shows the impacts of users’ decisions on the model. The workshop will be conducted virtually. Interactive audience engagement platforms will be applied seeking the active involvement of the participants.

Speaker	Rania Delidimou Civil Engineer, University of Patras / MSc Structural design and Retroffiting, NTUA Michalis Themelis Architect AUTh / MSc Architectural design, University of Thessaly
Topic	Restoration and reuse of two Pelion Architecture Monuments (brochure)
Date	23/2/2022, 11:00 (video (DIAVLOS, YouTube))
Abstract	The methodology followed for the study, renovation and reuse of two characteristic stone masonry examples of traditional Pelion Architecture as well as the all around procedures, laboratory checks and Central Monument Council authorisations needed. The assesment, performance under seismic loads and simulations according to the EN8-3 and the latest temporary Greek ΚΑΔΕΤ norm, as well as the N,3028/2002 law framework regarding restoration. The two buildings have three levels in stone masonry, free float stone roofs and partial wooden compound walls on the exterior shell. They were both abandoned for many years and their age is around 150-200 years old. Numerous checks were underheld, in parallel with laboratory checks and simulations in the most adequate software available so as to point the optimum retrofitting materials, quantities and reversible procedures.

Speaker	Valentina Laface (CV) Assistant Professor, University of ​​Reggio Calabria, Italy
Topic	The use of storm models in the field of ocean engineering (brochure, presentation)
Date	9/3/2022, 11:00 (video (DIAVLOS, YouTube))
Abstract	The category of Storm Models approach will be discussed in detail with reference to each of the models belonging to this category. Their application for long-term analysis of ocean storm will be explained and analogies and differences among them will be highlighted. Further, alternative use of this models for ocean engineering application such as energy and downtime estimation as well as extreme wind speed calculation will be presented. These models have the peculiarity to use a simplified storm time history to model the specific problem whatever is the kind of analysis. The simplified storm differs from one model to another and is determined by imposing a kind of equivalence between important storm parameters of actual and equivalent storm.

Speaker	Dr Szymon Cholostiakow (CV) Post-Doctoral Researcher, Concrete Technology and Reinforced Concrete Structures Lab
Topic	Use of FRP as internal shear reinforcement of concrete elements (brochure)
Date	23/3/2022, 11:00 (video (DIAVLOS, YouTube))
Abstract	Owing to the unique mechanical characteristics and lack of plasticity of fiber-reinforced polymers (FRPs), relatively large strains can develop in FRP reinforced concrete (RC) elements at ultimate limit states and this can lead to different relative contributions of concrete and shear reinforcement to the total element's shear capacity. This presentation examines the development and relative contribution of the main shear resisting mechanisms in concrete beams with different overall depths and reinforced with longitudinal and transversal FRP reinforcement. Complementary strain measurements obtained from digital image correlation (DIC) and strain gauges are presented and discussed thoroughly. Although current FRP shear design approaches rely on the assumption that the contributions of concrete and shear reinforcement are constant up to failure, their relative magnitude is found to vary with increasing crack width. The experimental results indicate that, when minimum shear reinforcement is provided, current shear models based on a fixed truss angle approach tend to overestimate the contribution of concrete and underestimate the contribution of shear reinforcement. The use of a variable angle truss model, along with an appropriate reduction in the contribution of concrete, would lead to a more reliable estimate of the main shear resisting mechanisms and optimal design of the required amount of shear reinforcement.

Speaker	George Mantanis (CV) Professor, Department of Forestry, Wood Sciences and Design - Laboratory of Wood Science & Technology, University of Thessaly
Topic	Innovative products of wood modification – Uses in outdoor structures (brochure)
Date	30/3/2022, 11:00 (video (DIAVLOS, YouTube))
Abstract	This lecture is related to state-of-art technologies of thermal and chemical modification of wood, which result in highly innovative wood products with improved physical, mechanical, chemical and biological properties. The lecturer, following a short introduction in wood modification, attempts to display main drawbacks of the natural material, which shall be limited and/or restricted. Then, he shortly presents two of the most prominent products of chemically modified wood, which can be of interest for the new civil engineer and architect, designer, or technologist. Nowadays in Europe, such new modified wood products can be encountered in a variety of outdoor applications. In addition, the chemical processes of acetylation and furfurylation of wood are briefly discussed; useful technical feedback is given from the international bibliography and the Greek practice, in which they have been tested in recent years. At the end, the lecturer presents the method of thermal modification of wood, and a relevant thermally-treated product, which is used mostly in claddings and outdoor decks.

Speaker	Grigorios Tsinidis (CV) Assistant Professor
Topic	Underground structures against seismic ground excitation: From seismic behavior and design to seismic vulnerability and resilience assessment (brochure)
Date	6/4/2022, 11:00 (video (DIAVLOS, YouTube))
Abstract	Underground structure (for instance, tunnels, subway stations, embedded pipelines, etc.) constitute crucial elements of road and rail transportation networks, as well as of energy transmission infrastructure, and are constructed at an increasing rate in seismic prone areas. Considering the vital role of these structures, as well as the significant losses associated with potential seismically induced damage, their adequate seismic design, as well as seismic vulnerability and resilience assessment, are of foremost importance for stakeholders, operators, and governmental bodies. Within this lecture, topics related to the behavior and design of underground structures subjected to ground seismic shaking will be presented, focusing on cases of circular or rectangular tunnels embedded in soft soils. In addition, recent developments in the vulnerability and resilience assessment of underground structures (e.g., tunnels and embedded natural gas pipelines) subjected to ground seismic shaking, will be presented. The above topics will be discussed through the presentation of representative results of advanced numerical analyses and experiments (i.e., tests on model tunnels in geotechnical centrifuges), conducted in the frame of relevant recent research projects.

Speaker	Thanasis Triantafillou (CV) Professor, Department of Civil Engineering, University of Patras
Topic	Integrated Structural and Energy Retrofitting of Existing Structures with Advanced Materials (brochure)
Date	25/5/2022, 11:00 (video (DIAVLOS, YouTube))
Abstract	The scope of the seminar is to present the properties, applications and the great potential of a relatively new generation of composite materials in the field of structural engineering. This new generation of materials comprises inorganic matrices (cementitious or non) reinforced with high-strength textiles (e.g. carbon, glass or basalt fiber textiles), which are either externally bonded on the surfaces of existing structures’ structural elements as a means of enhancing their properties (e.g. strength, ductility), or they are used as internal reinforcement in new structures. Focus will be given on the applications of textile-reinforced mortars in existing reinforced concrete structures when the target is to increase the flexural or the shear capacity of structural elements, or to enhance the local ductility of structural members through confinement. An overview of applications of textile-reinforced mortars in strengthening masonry structures (for in-plane or out-of-plane actions) is also included. Finally, an integrated structural and energy retrofitting system based on the use of textile-reinforced mortars will be presented.

Speaker	Ambrosios-Antonios Savvides (CV) Dr. Civil Engineer from National Technical University of Athens (NTUA), Lecturer at Department of Civil Engineering at University of Thessaly
Topic	Open source Finite Element Code for numerical simulations in computational mechanics problems: MSolve. Presentation and capabilities (brochure)
Date	1/6/2022, 11:00 (video (DIAVLOS, YouTube))
Abstract	The scientific field of Computational Mechanics is one domain of significant importance for Civil Engineers. For all infrastructures like houses, dams, bridges, railways etc the complexity of the load bearing bodies and the loadings subsequent to high quality requirements for the infrastructure. Therefore, the demand for large scale computations is constantly increasing. The evolution and progress of the computer science and software engineering contributes to the satisfaction of this demands. In this lecture an open source Finite Element Code for numerical simulations in computational mechacnis problems is presented. The capabilities and advantages of the aforementioned code will be postulated alongside with fields of improvement which are under investigation and development. Finally, the access to the following code will be provided and a discussion for dissemination purposes will be followed.