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.
Finite element analysis for CFST columns under blast load
The impact of blast load is always taken into consideration in significant building and protective construction.Presently,concrete filled steel tubular(CFST) is widely used in construction because it has the beneficial qualities of both concrete and steel.In order to study the mechanical behavior of the CFST column under blast load the dynamic responses of a square CFST column under surface explosion were simulated by the nonlinear finite element program ANSYS/LS-DYNA.The JHC model was used for concrete material and the MAT-PLASTIC-KINEMATIC model which accounted for the strain rate used for steel.The failure behavior of the CFST column at scale distance equal to 1.0 was analyzed.The results indicate that the inner concrete was seriously damaged,while the deformation of concrete was restricted by the steel tube.It shows that CFST column has excellent ductility and blast resistance.The time-history curve of displacement of key nodes at different scale distance were compared,which indicates that the deformation of the column obviously decreases with the increase of scale distance.
Application design of a sun-tracking system
As a very good renewable energy, solar energy gets a lot of countries' concerns. How to improve the efficiency of solar panel is now a hot topic and sun tracking is one of the solutions. In this paper, a servo tracking system using dSPACE DS1104 R&D controller board is designed to improve solar collection efficiency. It combines electro-optical tracking and sun trajectory tracking, and can keep solar panels perpendicular to the sun during daylight hours. In order to reduce the amount of computation, a T-S fuzzy system based sun trajectory tracking is proposed. Because of the seamless connection between dSPACE and MATLAB/Simulink, the development cycle time is short. Experimental results show that the system can track the sun precisely and has higher efficiency.