Development of a Matrix Method Based Framework for the Thermo-Mechanical Analysis of RCC Frames

Reinforced concrete frames are one of the predominant structural systems which are commonly used in India. Fire resistance is an important design aspect as fire is one of the most severe environmental conditions to which structures may be exposed to during their life time. Typical fire resistance analysis involves evaluation of temperature across the structural member and incorporation of the thermal effects in structural analysis by temperature dependent material models of concrete and steel employing various numerical schemes. The main limitation of these methods is that they evaluate the fire resistance of individual structural components and they lack the competency to quantify the response of whole structure. Thermo-mechanical analysis can be carried out in commercial finite element software like ANSYS but modeling an entire structure is computationally very intensive. To alleviate these difficulties, a matrix analysis methodology has been developed incorporating the effects of thermal strains as well as temperature dependent material models of concrete and steel. The key strength of matrix analysis lies in its computational efficiency compared to ANSYS while producing results of reasonable accuracy. Numerical examples are presented to demonstrate the efficacy of the developed methodology.