Wind-induced vibration of a long span space truss structure
In this paper, characteristic of wind-induced vibration of a a long span space truss structure was studied. Wind tunnel test was conducted in a boundary wind tunnel, based on which displacement along Z direction under all wind directions are discussed, and vibrations of typical nodals are emphasized. It is shown that the upwards corner of the roof may course greater peak displacement in this area than that in other areas. On the other hand, modal vibration of part area may be much greater than that of others, which may enhance the danger of local wind induced structural damage of these areas.
WIND RESPONSES ANALYSIS METHOD OF SPATIAL LATTICE STRUCTURES IN FREQUENCY DOMAIN WITH MODE COMPENSATION
The frequency domain method is the first adopted method for the analysis of wind responses of large span spatial structures. Because the large span spatial structures have dense frequencies, the frequency domain method is never suitable for these structures. In China, the high rise structures load code is used for the large span spatial structures, only the first frequency is taken account for the wind vibration analysis, which is not reasonable. According to the contribution of modes to strain energy of system, this paper presented a simple and efficient method to compute the wind vibration coefficient of large span spatial structures. The effectiveness of the proposed method is verified by a numerical analysis of the wind responses of a spherical dome.
Investigation of International Standard, International Electrotechnical Commission, IEC 62305 and Indian Standard IS 2309 in positioning the Air Terminals (ATs)
From 18th Century onwards, many scientists and researchers across the globe have conducted experiments and researches related to the subject called Lightning and as a result they have acquired success in protecting the structures against lightning strokes to a great extent. However, the science behind lightning has not been completely discovered and therefore any design of lightning protection scheme can’t be certified as cent percent safe. Here in this paper, a cuboid equivalent to a rectangular industrial building has been taken into consideration. Lightning Protection Scheme for the same has been designed in two ways: i) based on the Protective Angle Method and Rolling Sphere Method as per International Standard IEC 62305 and ii) based on the Protective Angle Method as per Indian Standard IS 2309. This paper mainly focuses on the comparison of those two designs which ultimately discloses the difference in safety level that we are having by adopting a particular standard.