Magnetism-mechanics Performance of Magnetically Controlled Shape Memory Alloy and Application For Active Control System

To control the dynamic stability of light steel structure, magnetism-mechanics performance of magnetically controlled shape memory alloy (MSMA) was studied, the MSMA actuator and MSMA active control system was developed. The material properties of MSMA related to magnetism and mechanics was studied, at the same time, the influence of the Ni-Mn-Ga contained in MSMA on the magnetism-mechanics properties was analysed, Ni53Mn25Ga22 was selected to build the design theoretical basis of MSMA actuator. Taking three MSMA rods with a size of 4x8x45mm as the core element, a new type of actuator was developed, and the corresponding magnetism-mechanics performance test was carried out. The key factors such as magnetic field, de-formation rate, preloading, active control force, etc. were determined, as well as the mathematical models with the changes of parameters were established. The controlled object (steel truss model structure), MSMA actuator, control algorithm, data acquisition system, etc. constitute the MSMA active control system. Two MSMA actuators are installed on the steel truss model structure, under the excitation of sine wave, the dynamic response of the steel truss model structure with the MSMA active control system was tested, and the results was compared with uncontrolled; The results show that the acceleration response of the steel truss model structure equipped with the MSMA active control system decreased by about 25%, and the displacement response decreased by about 20%. The active control system with MSMA actuator as the core component can better realize the dynamic stability control of steel structure.