Dynamic Responses of RPC-Filled Steel Tubular Columns Post Fire Under Blast Loading
Blast-resistant capacities of 4 large scale circular Reactive Powder Concrete Filled Steel Tubular (RPC-FST) columns after exposure to fire are experimentally examined. The overpressures of shock wave, the deflections and strains of RPC-FST column specimens are recorded by advanced gauges. The influences of fire durations and scaled standoff distances of explosive charge on the dynamic behaviors and failure modes are discussed. It is shown that the RPC-FST columns remain excellent blast-resistant capacities after exposure to fire. RPC core column can be effectively confined by steel tube, but the blast-resistant capacities of RPC-FST columns are decreased as explosive charge or fire duration increased. The failure modes are transited from bending types to bendingshear types as explosive charge increased, and an obvious plastic hinge at mid-span section can be observed in the RPC-FST column with fire duration of 105min. It is also indicated that the maximum displacements of RPC-FST columns are more sensitive to fire duration than to explosive charge weight.
Study of Circular Reactive Powder Concrete-filled Steel Tube Stub Columns under Axial Compression
As a fundamental mechanical problem in steel and concrete composite structures, the axial compressive behavior of reactive powder concrete (RPC)-filled steel tube stub columns has been a concern of scholars worldwide. At present, the analysis method of RPC-filled steel tube is based on nonlinear finite element method and equivalent uniaxial stress–strain analysis model, but the analysis process is complicated and cannot accurately describe the interaction between the steel tube and RPC. Thus, this study proposed a nonlinear analytical procedure to evaluate the mechanical properties of steel tube and RPC accurately at different compressing stages. The method was employed to predict the load–deformation curves of RPC-filled steel tube stub columns under axial compression. Compressing experiments were conducted on such columns, and the characteristic hoop coefficient was derived. Comparison analysis was performed to verify the accuracy and efficiency of the analytical procedure. Results demonstrate that the characteristic hoop coefficient is a critical value for assessing whether the steel tube yields when columns reach the ultimate bearing capacity. Columns with small hoop coefficient have good ductility, but the material utilization rate of the steel tube is not high. Columns with large hoop coefficient have weak ductility and residual deformation capacity. Moreover, columns with characteristic hoop coefficient can reach good ductility and high material utilization rate. The characteristic hoop coefficient determined by the test analysis in this study is approximately 1.3. The analytical results are generally in good agreement with the experimental results until the starting position of strain hardening or local plastic buckling. The proposed method provides a good prospect for optimizing the design of RPC-filled steel tube columns.
Constructing gender and locality in late medieval England : the lives of Anglo-Saxon and British female saints in the South English Legendaries
..........................................................................................2 Acknowledgements.............................................................................5 Introduction....................................................................................8 1. Female Saints in the SELS 2. The SEL Manuscripts of Monastic Women’s Lives 3. Narratives of Medieval Monastic Women Chapter 1 Saint Frideswide of Oxford and Topoi of Virginity........................42