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 NewtonRaphson method and arch length control. However, the NewtonRaphson method can diverge and not produce a result, for example in bifurcations or during snapback. In order to enhance the robustness of solving nonlinear problems, a new method – called incremental sequentially linear analysis (ISLA) – is proposed. The method is based on a combination of the NewtonRaphson 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 nonproportional loading, geometrically nonlinear analysis and transient analysis. The robustness of ISLA has been demonstrated in four examples: a concrete beam with both prestress and vertical load; outofplane bending of a masonry wall with overburden; a differential settlement test on a preloaded masonry façade and a 3D pushover analysis of a masonry house.
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 nonproportional loading, geometrically nonlinear analysis and transient analysis. The robustness of ISLA has been demonstrated in four examples: a concrete beam with both prestress and vertical load; outofplane bending of a masonry wall with overburden; a differential settlement test on a preloaded masonry façade and a 3D pushover analysis of a masonry house.
Original language  English 

Qualification  Doctor of Philosophy 
Awarding Institution 

Supervisors/Advisors 

Award date  3 May 2019 
Print ISBNs  9789402814767 
DOIs  
Publication status  Published  2019 
Keywords
 Structural mechanics
 Computational mechanics
 Fracture mechanics
 Quasibrittle materials
 Incremental
 Saw tooth model
 Sequentially linear analysis (SLA)
 Smeared crack model
 Damage model
 Strong discontinuity
 NewtonRaphson (NR) method
 Piecewise, Iterative
 Implicit
 Explicit
 Masonry
 Concrete