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.
Substation automation based on IEC 61850 with new process-close technologies
New technologies in primary equipment like nonconventional instrument transformers require new interfaces to the substation automation system. The future standard IEC 61850 perfectly supports this requirement. With the introduction of the new technologies and the use of IEC 61850, a more decentralized architecture of the substation automation system will be possible. This provides several benefits but a careful system design is required to maintain the overall reliability of the system.