18SC009 - Modelling Approaches for Masonry Structures

Instructors:

Georgios E. Stavroulakis, Technical University of Crete, Greece

Georgios A. Drosopoulos, University of KwaZulu-Natal, South Africa

This course has been designed so as to satisfy specific outcomes, and provide the participants the opportunity to realize challenges and modelling techniques for the evaluation of the structural behaviour of masonry structures.

After the course, the participants will be able to:

  • Realize challenges and common difficulties related to modelling masonry structures.
  • Understand the wide range of methods, used to depict masonry’s structural behaviour.
  • Realize advantages-disadvantages of the mentioned methods.
  • Implement the presented methods in a range of problems.
  • Understand the general framework of the usage of commercial finite element packages (Abaqus, Ansys) and simplified Matlab models for modelling masonry structures.
  • Encounter practical difficulties related to numerical analysis in non-linear simulations.
  • Establish - further develop a valid research profile in masonry structures.

Towards these goals, electronic handouts, slides of presentations, input data for application examples and representative solved problems will be provided to the participants.

Objectives of the course

During the last hundreds of years, masonry is used for the construction of several type of buildings: residences, bridges, churches, domes, etc. Despite the wide usage of the material, there are still several challenges for the accurate representation of the structural behaviour of it. These are mainly attributed to the heterogeneous nature of masonry: masonry blocks or bricks, connected at mortar joint interfaces. Masonry blocks are stronger in compression than in tension, resulting in a smaller tensile resistance. Shear failure type is also involved.

To account for these issues, several numerical methods appropriate for the simulation of masonry structures have been developed. Among others, three fundamental categories are mentioned here:

  • Discrete methods
  • Continuous methods
  • Multi-scale methods

Discrete methods rely on the explicit simulation of the interfaces and multi-body systems, appearing in masonry structures. Continuous methods describe the mechanical behaviour of masonry using constitutive laws taken from continuum mechanics. Someone may identify both traditional (Mohr-Coulomb, Drucker-Prager) and modern approaches (damage mechanics). Both discrete and continuous methods describe the constitutive behaviour of masonry in a structural level. That means that all the non-linear phenomena, derived even from the micro-structure, are accounted for in a macroscopic level. To consider the microscopic scale, multi-scale methods focus on the detailed description of masonry’s constitutive behaviour in a microscopic scale and the proper derivation of average properties, which can be used in the macroscopic structural scale.

Finite element analysis is the most common numerical tool used for the implementation of those methods. From another point of view, limit analysis methods can be used for a fast representation of the structural performance with a smaller computational cost.

In the framework of this course, the participants will have the opportunity to receive up-to-date information related to the aforementioned main approaches used to simulate masonry structures. Representative examples and hints for the effective usage of existing software packages, will be presented.

In particular, the following topics will be covered:

  • Short introduction to finite element analysis
  • Non-linear finite element analysis oriented to the study of masonry structures, classical continuous elastoplastic models
  • Dynamic analysis for masonry (modal analysis, non-linear time history)
  • Incorporation of elements from non-smooth contact mechanics, unilateral contact interfaces as potential cracks.
  • Consideration of the microscopic/mesoscopic masonry structure: homogenization, multi-scale methods
  • Limit analysis, discrete element methods
  • Photogrammetry techniques and post-mortem analysis of masonry structures, damage identification, parametric simulation and optimization
  • Hints for the effective usage of existing software
  • Application examples and discussion

Target groups

  1. Graduate students, researchers and junior faculty members
  2. Junior structural analysis engineers, architects specializing in masonry analysis and rehabilitation