Mechanical Response Modeling of Column Experiments

In this chapter, the post-fire behavior of FRP composites was evaluated and modeled on the stmctural level. Results from the models compared well with results from fuU-scale post-fire experiments on cellular GFRP beam and column specimens that had been subjected to mechanical and thermal loading up to 120 min with inclusion of different thermal boundary conditions. On the basis of the previously proposed thermal and mechanical response models, existing approaches for post-fire evaluation can be applied. Predicted temperature profiles and the conversion degrees of decomposition can be used to estimate the post-fire stiHhess from existing two- and three-layer models. The borders between different layers can be determined either by a temperature criterion or a RRC criterion. 

An internal liquid cooling system as an active fire protection was implemented in full-scale GFRP panels for beam and column applications, the resulting thermal responses have been introduced and modeled in Chapter 6 and the mechanical responses in Chapter 7. The fire endurance time of each scenario is summarized in Table 9.1 and more details can be found in the previous chapters. It can be concluded that combined mechanical loading and fire experiments on full-scale water-cooled cellular slabs and columns proved the feasibility of an effective fire protection. Fire endurance durations of up to 2 h could be reached at slow water... 

After the removal of La from the third column of the periodic table, the problem still remained to explain its anomalously high Tc. Hamilton and Jensen (1963) and Kuper et al. (1964) therefore proposed a new pairing mechanism for La (and also for U) different from the normal electron-phonon interaction in order to specifically account for the superconductivity. The model involved a sharp unoccupied 4f level just above the Fermi energy. The theoretical model predicted that the reduced gap lAlkaTc should deviate significantly from the value of the BCS theory. This prediction was not confirmed by specific heat measurements (Johnson and Finnemore, 1967) or the most recent tunneling experiments (see section 2.2). On the contrary, from the phonon-induced structure in the tunneling characteristic one can conclude that the electron-phonon interaction is responsible for the superconductivity of La. 

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