This paper on "Nonlinear Analysis of Fire-Resistant Masonry" was presented at the NAFEMS World Congress on Effective Engineering Analysis - 25-28 April 1999, Newport, Rhode Island, USA.

Summary

The analysis of masonry suffers under the different behaviour of a brick construction in the compressive and tensile direction of the straining. Additionally the three orthogonal directions behave more or less independant from each other, which excludes the usage of the normal isotropic material laws. In a finite-element-model every brick should be idealized ideally by an own element, which should be connected by any sort of contact condition or element. As this is not practicable a continuum model is used, where a orthotropic material law leads to the desired effects. In a fire-resistant masonry additionally a temperature load is permanently resident, which leads to temperature-dependant material properties and, as the temperatures may reach up to 1650^oC, an additional creep and yield effect is noticed simultaneously.
At several examples, different constructions of converter linings and different constructions of coke cooling equipments, the analysis of steady-state and time-transient temperature field analysis is performed. In coupled mechanical analysis the behaviour of the bricks are demonstrated and the interaction with the surrounding steel-construction, which is bearing partially the load, is also shown. Most of the steady-state temperature loads disappear due to the creep effect in the stones. Fast changes in the temperature lead to high stress concentrations and to yielding or even britteling of the stones. In some cases also the gaps between the brick are widening and a danger of the collapse of the self-carrying stone structure occurs. In some variational designs the weak points of the constructions could be eliminated on the basis of the numerical results.