Webinars

8th International Symposium on Solid Mechanics

Mecsol 2022 Webinar Series was a program of online talks by scholars working on the state of the art of Solid Mechanics, which were held prior to the conference. Recordings of some of the webinars are available on our Youtube Channel.

Mecsol 2022 Webinar Series #1

Structures and components under impact loading
Speaker: Marcílio Alves, University of São Paulo
Friday, October 22, 2021, 2-3pm (GMT-3)

Abstract: Structures and components, when subject to high intense and dynamic loading, present a complex response, exposing inertia effects, material nonlinear response, wave propagation, failure and other phenomena. Such a multitude of aspects require an integrated approach of analysis, where experimental techniques, numerical analysis and a firm theoretical background should all be put at use on what they have of more advanced. Here, some of these aspects of impact engineering are presented based on a wide collection of studies. Examples include human body response to crash accidents, impact on plates and shells, measurement of dynamic strength properties of materials, behavior of additive manufacturing components under impact loading, failure of materials, scaling of structures, ship collision, etc.
Chair: Marco Lúcio Bittencourt (Unicamp)
Watch the recorded webinar here.

Mecsol 2022 Webinar Series #2

Non-cuttable material inspired by nature
Speaker: Stefan Szyniszewski, Durham University
Friday, November 19, 2021, 2-3pm (GMT-3)

Abstract: The talk will introduce a cellular structure made of aluminium and ceramics, which resembles micro-structures of sea creature shells and grapefruit peel. We called the material Proteus as it modifies its internal structure under different loads. The talk will discuss the properties and applications of this newly developed material technology.
Chair: Luiz Carlos Marcos Vieira Jr (Unicamp)
More information and free registration here: bit.ly/mecsol2

Mecsol 2022 Webinar Series #3

Railway induced vibration in the built environment: assessment, prediction, and mitigation
Speaker: Geert Degrande, KU Leuven
Friday, January 28, 2022, 2-3pm (GMT-3)

Abstract: Considerable progress was made during the last decades in developing numerical prediction models for railway induced vibration in the built environment. Accurate numerical prediction of railway induced vibration in buildings remains very challenging, however, due to the complexity of the coupled dynamic soil-structure interaction problems involved, the wide frequency range of interest, the large number of determining parameters, and the uncertainty involved. Despite all efforts taken to identify the properties of the track, soil, and building, the predicted and measured response in the free field and in the building differ by 10 dB in the dominant range of frequencies. The incident wave field due to impacts on the sleepers and train passages is very sensitive to uncertain dynamic soil properties, which in turn also explains the observed discrepancy between the predicted and measured response of the building. Industry experiences a strong need (1) to conduct extended parametric studies, (2) to optimize vibration mitigation measures in a robust way, and (3) to quantify and reduce model and parameter uncertainties. These applications all require detailed vibration prediction models that are fast to run; we will therefore investigate the potential of model order reduction techniques to considerably speed-up state-of-the-art prediction models. There also remains a need for scoping models that are fast to run and can be used in an early design phase on a larger urban scale; we therefore also plan to further develop hybrid prediction models that combine numerical prediction with experimental results.
Chair: Josué Labaki (Unicamp)
More information and free registration here: bit.ly/mecsol_3

Mecsol 2022 Webinar Series #4

GFRP profiles subjected to fire: from laboratorial test to multiphysics modelling
Speaker: Carlos Manuel Tiago Tavares Fernandes, University of Lisbon
Friday, February 18, 2022, 2-3pm (GMT-3)

Abstract: Glass Fibre Reinforced Polymers (GFRP) have several advantages over conventional building materials, namely in terms of strength, self-weight, insulation properties and durability. Although the mechanical and physical properties of pultruded GFRP profiles are reasonably studied, their response to fire is still an active topic of research. Even though flame retardants and phenolic resins have been proved to improve fire reaction properties significantly, in order to fulfill fire resistance requirements, there is a need to develop adequate fire protection systems to allow the use of GFRP profiles in buildings and other applications. Laboratory tests are the primary way of studying the problem, but their applicability is limited due to the high number of parameters involved in the study, such as the geometry of the profile, type of protection system (active or passive), number of exposed faces to fire, applied load, etc.
In the present work, we develop a numerical model capable of accurately predicting the temperature distribution and the mechanical response of tubular section profiles made of GFRP, including the possibility of incorporating fire protection systems. Its main ingredients are:
(i) A thermal 2D model that predicts the temperature distribution inside the GFRP profile when exposed to fire in different scenarios, including conduction and natural convection of air and the internal radiation inside the cavity walls of the GFRP profile. The material decomposition is introduced by an Arrhenius equation. It is a non-linear, time-dependent coupled thermal/fluid dynamics/radiation problem;
(ii) The mechanical response of the GFRP profile is found by considering a geometrically exact large strains shells model with thickness variation, whose pure 3D constitutive model includes fiber orientation effects, thermal expansion, decomposition degree, and creep behaviour.
Chair: Marco Lúcio Bittencourt (Unicamp)
More information and free registration here: bit.ly/mecsol4

Mecsol 2022 Webinar Series #5

Epistemic uncertainties and their role in optimal design of engineering systems
Speaker: André T. Beck, University of São Paulo
Friday, March 18, 2022, 2-3pm (GMT-3)

Abstract: It is nowadays well accepted that engineering systems need to be designed considering the inherent uncertainties in demands and capacities. Reliability-based, risk-based and robust optimization are three modern approaches to address the optimal design problem under objective uncertainties, that is: uncertainties which can be quantified using probability theory. Yet, subjective epistemic uncertainties, related to limitations of knowledge and to human errors, cannot be quantified probabilistically, but also need to be considered in design optimization. In this talk, we discuss the role of epistemic uncertainties, by exploring examples of optimal design of structural systems.
Chair: Luiz Carlos Marcos Vieira Jr (Unicamp)
More information and free registration here: bit.ly/mecsol5

MECSOL 2022 WEBINAR SERIES #6

Programmable structures: encoding functionality in design
Speaker: Jovana Jovanova, TU Delft
Friday, April 8, 2022, 2-3pm (GMT-3)

Abstract: Structures that respond in desired ways once subject to external stimuli are called programmable structures. Programmability can be achieved with patterning unit cells resulting in uniquely designed metastructures, with integrations of smart materials or both. In my group we work on design of passive and active metastructures with tailorable mechanical properties, smart granular materials for soft robotics applications and bio-inspired lattice structures for drag reduction. We use multi-physics modelling approaches to capture the interfaces between the environmental stimuli and the structure response. We develop analytical and numerical models to introduce nonlinear behaviour (geometrical and material nonlinearities) to be able to quickly generate structure responses. Then we apply design optimization to maximize the structure functionality. We look into scalability of programmable structures and the effects of it in a large-scale domain, from manufacturing over design implications to real-scale implementation. In this talk I would show some examples of large scale metamaterial interface design for vibration attenuation in the offshore renewable energy sector; design for additive manufacturing of Nitinol lattice structures with tailored mechanical properties for energy absorption; design of piezoelectric metamaterials with exotic properties using machine learning; and smart grasper design with granular materials.
Chair: Josué Labaki (Unicamp)
More information and free registration here: bit.ly/mecsol6