Study on residual strength of concrete filled steel tube after exposure to explosing impact
The residual bearing mechanism of concrete filled steel tubular beams with different casing hoop steel coefficients after exposure to explosing impact were experimentally investigated. The experiments were carried out on the reaction frame for loading, and the pressure and the residual deformation modes were recorded. The results show that the concrete filled steel tubular beams have good anti-explosion ability and the casing hoop steel coefficient is an important factor to the value of residual strength.
Response of structural concrete elements to severe impulsive loads
Abstract The behavior and response of structural concrete elements under severe short duration dynamic loads was investigated numerically. The analytical approach utilized the Timoshenko beam theory for the analysis of reinforced concrete beams and one-way slabs. Nonlinear material models were used to derive the flexural and shear resistances, and the differential equations of the Timoshenko beam theory were solved numerically by applying the finite difference technique. A simplified approach was developed for estimating the strain rate in structural concrete members, and the corresponding strain rate effects on the strength of the steel and concrete were incorporated into the analysis. Detailed failure criteria were established for predicting the collapse of structural concrete members. Five cases subjected to localized impact loads and eleven cases subjected to distributed explosive loads were analyzed, and the results were compared to experimental data obtained by other investigators.
NEW DECAPODS FROM THE NAVIDAD FORMATION (MIOCENE) OF CHILE
Abstract A new Miocene decapod fauna is described from the Navidad Formation of coastal Chile. The fauna includes five callianassoid taxa, none of which is preserved sufficiently to identify to species level. New species include Calappilia? chilensis, Hepatus spinimarginatus, Proterocarcinus navidad, Pilumnus cucaoensis, and Pinnixa navidadensis. A possible rhizopine member of the Pilumnidae Samouelle, 1819, is described. Trichopeltarion levis Casadío et al., 2004, previously known from the late Oligocene of western Argentina, was also recovered from these rocks. Calappa circularis Beurlen, from the lower Miocene Pirabas Formation in Brazil, is herein referred to Calappilia. This report greatly increases the known number of fossil decapods from Chile and sets the stage for paleobiogeographic comparison of the decapod faunas of Chile and Argentina.