About

Project Summary

An alternative continuum theory called Cosserats’ or micropolar theory is considered within this proposal and a case is made for its more thorough analysis within the framework of the so-called fixed-pole description with the aim of providing accurate and efficient finite elements for linear and non-linear static and dynamic analysis.

The elements will be developed by pursuing a set of research objectives consisting of (O1) linear static analysis, (O2) non-linear static analysis, (O3) dynamic analysis and (O4) parameter identification. In this way, through objectives O1-O3 the elements developed will be usable as a simulation tool in their own right while in O4 they will make a vital pre-requisite for a robust and reliable procedure needed for identification of material parameters from experimental measurements. The finite elements will be tested against a number of bench-mark problems, while a couple of experimental setups will be designed to complete O4.

The objectives will be reached through a series of research, training and management activities led by the members of the project team and built on previous achievements of the team in finite-element design involving linked interpolation, objective configuration-dependent interpolation, time-stepping algorithms, conventional Cosserats’ elasticity, fixed-pole approach in geometrically exact beams as well as experience in performing contactless measurements.

State-of-the-art highlights:

  • Cosserats’ continuum theory is a generalisation of classical Cauchy’s theory, in which couple stresses exist at the particle level. It can describe certain experimentally observed phenomena, which the classical theory cannot and is particularly applicable to natural and man-made materials with internal structure.
  • The theory itself is well known, but reliable experimental methods to determine the material parameters are still lacking, as are also the numerical procedures, in particular in non-linear analysis.
  • The fixed-pole description relies on defining all the couples that exist in the system with respect to a unique point of reference – the fixed pole – and in this way opens new avenues for development. In 2D and 3D Cosserats’ theory, however, it has not been as yet satisfactorily exploited.

Project-relevance highlights:

  • The fixed-pole approach enables a novel mathematical description of the theory within a configuration space of unique algebraic properties, thus facilitating a numerical treatment, in particular in development of conservative time-integration schemes.
  • Owing to the algebraic properties of the configuration space, the objectivity of the implementation may be achieved using the methods already proposed by the applicant and the project team for geometrically non-linear beams, including those achieved within the CSF project CANFAS.

Methodology highlights:

  • Cosserats’ theory will be re-written in the fixed-pole description with a specific aim to develop virtual-experiment tools for parameter identification and simulation tools for engineering analysis. 
  • The finite-element numerical approach will be utilised and the new finite elements for linear and non-linear static and dynamic analysis developed within FEAP.
  • The finite elements developed for linear static analysis will be employed to enable inverse identification of the Cosserat material parameters from a couple of own experimental setups.

Work-plan highlights:

  • There are four principal project objectives: development of novel fixed-pole finite elements for (i) linear static analysis, (ii) non-linear static analysis, (iii) dynamic analysis and (iv) parameter identification.
  • The objectives will be reached through a series of research, training and management activities led by the members of the project team with suitable qualification achieved through earlier CSF and other projects.
  • Post-doctoral and doctoral researchers are vital members of the team, who will be fully employed on the project and trained to boost their career perspectives through research workshops and study visits.
  • The research activities will be monitored by the applicant through regular fortnightly project meetings; professional assistance will be provided in recruitment, procurement, equipment maintenance and upgrade.

Impact highlights:

  • Four full-size scientific publications in Q1 WoS journals are planned, in which the results of activities on the four principal objectives will be respectively presented.
  • The national and international events organised annually by Croatian Society of Mechanics will be regularly attended by two members of the project team.
  • Project sessions are planned for 10th International Congress and 11th Meeting of Croatian Society of Mechanics in 2021 and 2022.
  • In addition, one to four international conferences abroad will be visited each year by various members of the project team.
  • The project work and achievements will be presented to the general public via a dedicated project web-page and on annual Science Festival events in Rijeka.

Research team:

Gordan Jelenić, | Google Scholar
Dragan Ribarić, | Google Scholar
Edita Papa Dukić, | Google Scholar
Nina Čeh, | Google Scholar
Laura Žiković, | Google Scholar
Sara Grbčić Erdelj, | Google Scholar
Magdy Ismail, | Google Scholar
Maedeh Ranjbar Zefreh, | Google Scholar
Marin Grbac, | Google Scholar
Damjan Jurković, | Google Scholar

Institution:
University of Rijeka, Faculty of Civil Engineering

This project is financially supported by Croatian Science Foundation (CSF)