Research On The SMA Vibration Damping Control Based On Multi-point Input Space Under The Large Cross-grid Structure

Large-span spatial structures develop rapidly because of the new structure shape, elegant construction design and strong cross-ability,but this structure has the following characteristics as various forms of itself,modeling complex and changeable,bars and nodes numbers.Now,the research of this structure has focused on the performance of static stability.And its dynamic analysis and vibration control of disaster research has just begun.This article will set the Shape Memory Alloys(SMA) damper on the large-span flat grid to form intelligent damping energy bars and replace original bars.Through finite element analysis to research the effectiveness of vibration control to this structure using this method at multi-input.The main research work carried out the following:Firstly,the random multi-point time-history analysis method is introduced on the basis of previous studies in the thesis.Secondly,a test of the shape memory alloy materials is done,and the effect to its performance by strain amplitude is introduced.Introduces shape memory alloy materials constitutive model and performance.And combining with the test results and theory analysis design a new type of SMA damper.Thirdly,This article through the large-scale common software of ANSYS, compares dynamic response and internal force of the different under the ideal large cross-grid structure in the same input and considering traveling-wave effect.Compare the difference of the displacement and axial force of flat grid under the acceleration of 400 gal and 70 gal of EL-CENTRO-wave at multi-input.It proves that analysis large-span spatial structures must take into account multi-input.Finally,considering the adverse effects of the multi-point input of large-span spatial structure,setting the SMA damper on the large-span flat grid to form intelligent damping energy bars and replace original bars.In this paper,there are two ways to replace SMA damper bars,one is replaced some lower chord's bars,another is replace some web bars.And compare the effects of this two replacement situations.The analysis has indicated that the lattice type is not changed and the reasonable control is done with this method.So it is a new and superior method of energy dissipation.