High Temperature, Non-linear Numerical Analysis Of Reinforced Concrete Slab

It is a long-term and arduous task throughout human life to prevent and control fire. As reinforced concrete structure is a main kind of modern structural styles in structure engineering, its investigation in temperature field has become more and more significant. It is not only difficult to situate the fire field in the laboratory but also in a considerable risk as well as human and financial resources consuming. This thesis aims to demonstrate finite element numerical simulation study about temperature - stress field of reinforced concrete slabs under permanent loads when it is in high-temperature conditions. The research of reinforced concrete structure in this thesis has been divided into two major parts.Part I: First of all, the variational regulation about heat engineering parameters and the thermal mechanical properties in high-temperature of reinforced concrete in China and abroad have been summarized and compared through this thesis. After deriving suitable parameters, the temperature field of reinforced concrete slabs has been analyzed; in addition to that, the ultimate bearing capacity has been calculated. By simulating the scene of a fire temperature according to the ISO standard temperature elevation curve and temperature field distribution of reinforced concrete slabs under high-temperature conditions with the finite element software, different temperature curves that are apart from the fire surface have been presented in this thesis. Then through the temperature field in heat conduction theory, the initial conditions and boundary conditions have been determined, semi-infinite slabs have been solved with the Laplace transformation. The rationality of the finite element simulation value has been analyzed by comparing the finite element simulation value with the value of Laplace transformation. Then error analysis has been done by comparing the finite element simulation value with the experimental observed value.Part II: When the fire, besides its ability to sustain normal use loads, each component of building is also required to sustain extra temperature stress. As a result of border restrictions, the whole reinforced concrete structures will be deformed by the temperature stress in addition to that, a great internal force will be produced. In this thesis, temperature stress and differential deflection equation of the thin slab interior will be derived from numerical calculation; the finite element software has been used to simulated temperature stress and the deformation and strain of thin slab interior by the non-linear theory. In the end, the slab stress, strain and deformation can be analyzed based on the numerical simulation.