Study On Mechanical Properties Of The Rotational Steel Pins Damper

Due to the existing rotational dampers,some of the ultimate rotational deformation capacity needs to be improved,some of the structure is complicated and not easy to construct,and some of the energy dissipation capacity is insufficient.In order to solve the above problems,combined with the excellent and reliable performance of steel material,a new type of rotational metal damper-rotational steel pins damper is proposed,mainly to study the mechanical properties of rotational steel pins damper,the main research results and research content are as follows:(1)The fatigue performance of steel pins was studied by conducting equal amplitude cyclic loading tests on three specimens with different weakening forms of energy dissipating elements,and the results showed that the hourglass type and circular arc type pins have excellent fatigue performance,while the fatigue performance of straight pin type pins is poor compared with the first two.(2)Six rotational steel pins dampers with different weakened steel pins were designed and fabricated,and two loading regimes("increase-equal amplitude" loading and "increase-decrease amplitude" loading)were used to conduct low circumferential cyclic loading tests to study the effect of different loading histories on the cyclic mechanical behavior of the dampers.The results show that the hysteresis curve of the rotational steel pins damper is full,the shape is parallelogram,and the shape of the hysteresis loop is basically the same under the same amplitude,which shows excellent and stable hysteresis performance;the specimens enter the elastic-plastic state at a small turning angle(0.01 rad)and exhibit excellent hysteresis performance.The equivalent viscous hysteresis damping ratio can reach 0.49 at 0.08 rad,which has good energy dissipation capability;good ultimate rotational deformation capability,the ultimate angle can reach 0.08rad;good cumulative plastic deformation capability,the cumulative plastic deformation capability is extremely important for metal dampers,and it is recommended that the study of metal dampers Consider the evaluation of cumulative plastic deformation capacity;the loading history of the specimen has less influence on its hysteresis performance,energy dissipation capacity and cumulative plastic deformation capacity;the reliability of the damper damping mechanism and the feasibility of the working mechanism have been verified.(3)The numerical model of the rotational steel pins damper is established by using the finite element software ABAQUS,and the numerical simulation results are compared with the experimental results to verify the validity of the numerical model in simulating the hysteresis behavior of the damper;the damping mechanism is further studied by analyzing the stress-strain distribution of the damper;the influence of the key structural parameters of the steel pins on the hysteresis performance of the damper is studied.(4)The mechanical performance parameters of the rotational steel pins damper are calculated by theoretical derivation,the hysteresis behavior of the damper is simulated by using the improved Bouc-Wen model,and the parameters of the improved Bouc-Wen model are identified by using the particle swarm algorithm.The results of test and parameter identification are taken into account,and the theoretical equations of mechanical properties are modified to give a semi-theoretical and semi-empirical equation,and the design process of the damper is given.