From sequentially linear analysis to incremental sequentially linear analysis

Robust algorithms for solving the non-linear equations of structures of quasi-brittle materials

Doctoral thesis (2019)

Authors

C. Yu Applied Mechanics - CEG
Research Group
Applied Mechanics (CEG) (TU Delft)
Copyright: © 2019 C. Yu
DOI: https://doi.org/10.4233/uuid:b20beffc-f69f-4723-9c91-77da79861f62
Concrete Incremental Structural mechanics Damage model Fracture mechanics Computational mechanics Quasi-brittle materials Saw tooth model Sequentially linear analysis (SLA) Smeared crack model Strong discontinuity Newton-Raphson (N-R) method Piecewise, Iterative Implicit Explicit Masonry
More Info
expand_more

Published Date

2019

Language

English

Reuse Rights

Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.

Faculty

Civil Engineering & Geosciences

Department

Materials- Mechanics- Management & Design

Research Group

Applied Mechanics

Abstract

It is difficult to accurately predict the strength of masonry and concrete structures. The most widely used method for simulating their behaviour is finite element analysis with the Newton-Raphson method and arch length control. However, the Newton-Raphson method can diverge and not produce a result, for example in bifurcations or during snap-back. In order to enhance the robustness of solving non-linear problems, a new method – called incremental sequentially linear analysis (ISLA) – is proposed. The method is based on a combination of the Newton-Raphson method and a total approach called sequentially linear analysis.

In ISLA, local damage is induced by reducing the material secant stiffness of the element that fails a unity check. The load is applied in force increments or displacement increments, which are adjusted to trace the complete structural response.

It has been showed that ISLA can handle non-proportional loading, geometrically non-linear analysis and transient analysis. The robustness of ISLA has been demonstrated in four examples: a concrete beam with both prestress and vertical load; out-of-plane bending of a masonry wall with overburden; a differential settlement test on a pre-loaded masonry façade and a 3D pushover analysis of a masonry house.