Numerical formulations for the analysis of advanced materials and structures

Abstract

The development of new materials is a very important activity in the search for new structural engineering solutions. With the advent of new manufacturing techniques, some new materials can be designed as, for example, metamaterials. Metamaterials are a result of the combination of different materials in the constitution of their macro (or micro) structure leading different properties from those found in nature. Not only metamaterials, which are very popular today, are the result of this combination, but also all materials called composites. Both for the design of new materials and for the proper understanding of the behavior of composite materials, the existence of physical-mathematical models and dedicated numerical methods are essential. These numerical tools (softwares) are essential for the good modeling of civil, mechanical, aeronautical, naval structures, etc. For this reason, the numerical methods and physical-mathematical models must always be updated and incremented, since new structures must be designed with new materials and old structures must be reinforced or demolished. This research project aims to develop numerical methods for the design and mechanical analysis of complex materials (artificial or not), as well as structures in critical situation as progressive collapse (intentional or not). In this sense, the appropriate modeling of materials and the combination between them, as well as the simulation of structures in a post-critical regime are part of the scientific and technological challenges of the project. A well-highlighted scientific challenge of this project is the proposal and validation of a single constitutive model for the modeling of solids (in elastic or plastic regime) and viscous fluids, Newtonian or not, in a Lagrangian version, which facilitates the multiphase coupling of materials. Another innovative contribution is the introduction of numerical connection devices between parts of structures composed of thin-walled structural elements, enabling the concomitant analysis of global and local post-critical behaviors of this kind of structures. A third contribution of this project is the introduction of two degrees of freedom of cinematic enhancement for an accurate representation of shear stresses in symmetrical and non-symmetrical laminated shell elements. The financing of this project also allows the continuation of research and validation of specific constitutive models for the analysis of materials composed of fibers and particles immersed in a cement matrix, under development in the group since 2010. In general, the technological challenges associated with modeling composite materials and complex structures is the development of numerical coupling procedures between components such as contact, inclusion, 'boundary layers' etc. To proceed with good numerical processing of these strategies the parallelization of different computational procedures are also a challenge. (AU)