Study On Additional Effective Damping Ratio Calculation Methods Of Energy Dissipation Structures

The additional effective damping ratio is an important parameter in the design of the energy dissipation structure.However,the existing additional effective damping ratio calculation methods have a large approximation.In this paper,the additional effective damping ratio calculation methods is studied deeply,and the more effective and accurate methods are explored.The main research work and achievements are as follows:(1)Aiming at the existing additional effective damping ratio calculation methods,the calculation theory or calculation principle is introduced.The advantages,disadvantages and applicable conditions are summarized and compared.(2)Aiming at the more commonly used free vibration decay method and the cumulative energy ratio method,a detailed method to get the data is given.Combined with the engineering,the strain energy method,the free vibration decay method and the cumulative energy ratio method are compared.The results show that the calculation results obtained by the three calculation methods are not much different.The strain energy method are stable,but the accuracy is slightly low,slightly more complex.The cumulative energy ratio method has a slightly higher accuracy and simplicity,but the stability is poor.The free vibration decay method stability,accuracy,complexity are between the strain energy method and the cumulative energy ratio method.It is suggested to use the strain energy method as much as possible,the free vibration decay method and the cumulative energy ratio method can also be added to the specification for check,auxiliary calculation or rapid estimation.(3)Aiming at the widely used strain energy method,the time-varying characteristics of the additional effective damping ratio and the envelope properties of the code method are expounded.The problem of the existent time-varying method is pointed out,and the improved time-varying method is proposed.Combined with the engineering,the above methods are compared.The results show that the envelope method is simple,but the calculation accuracy is relatively low.The time-varying method can not reasonably and accurately calculate the additional effective damping ratio.The improved time-varying method has a higher calculation accuracy,but is more complex.The comprehensive method calculation accuracy and computational complexity are between the envelope method and the improved time-varying method.The accuracy is relatively high when the additional effective damping is low.It is suggested to use the improved time-varying method in the code to calculate the additional effective damping ratio and to recommend the preparation of the relevant data extraction and to write the relevant data extraction and data processing procedures to improve the computational efficiency.(4)Aiming at the envelope method and the improved time-varying method,it is proposed to use the interlayer harmful displacement to calculate the structural strain energy.A reasonable and feasible method is given to extract the harmful displacement.Combined with the engineering of the use of interlayer displacement and the use of interlayer harmful displacement for comparative analysis.The results show that both the envelope method and the improved time-varying method,the use of interlayer harmful displacement is more accurate than the use of interlayer displacement.The improved time-varying method using the interlayer harmful displacement has the highest accuracy,but is the most complex.For the improved time-varying method,the calculation results are not much difference.The improved time-varying method using the interlayer displacement is slightly more accuracy and more simple than the envelope method using the interlayer harmful displacement.It is suggested to use the interlayer harmful displacement to calculate the additional effective damping ratio in structure of bending shear deformation or bending deformation in the case of high accuracy requirements(5)Aiming at the speed-dependent energy dissipation components,the power method is proposed.The difference between the power method and the strain energy method is revealed.Combined with the engineering,the power method,the strain energy method and the timevarying strain energy method are compared.The results show that the strain energy has the lowest accuracy but is simple.The time-varying strain energy method has the highest accuracy,but it is complex.The power method is more accurate,only slightly lower than B,and simple.It is suggested to use the power method to calculate the additional effective damping ratio offered by peed-dependent energy dissipation components.